@misc{RichterRachowIsraeletal., author = {Richter, Jana and Rachow, Fabian and Israel, Johannes and Roth, Norbert and Charlafti, Evgenia and G{\"u}nther, Vivien and Flege, Jan Ingo and Mauß, Fabian}, title = {Reaction Mechanism Development for Methane Steam Reforming on a Ni/Al2O3 Catalyst}, series = {Catalysts}, volume = {13}, journal = {Catalysts}, number = {5}, issn = {2073-4344}, doi = {10.3390/catal13050884}, pages = {23}, abstract = {In this work, a reliable kinetic reaction mechanism was revised to accurately reproduce the detailed reaction paths of steam reforming of methane over a Ni/Al2O3 catalyst. A steady-state fixed-bed reactor experiment and a 1D reactor catalyst model were utilized for this task. The distinctive feature of this experiment is the possibility to measure the axially resolved temperature profile of the catalyst bed, which makes the reaction kinetics inside the reactor visible. This allows for understanding the actual influence of the reaction kinetics on the system; while pure gas concentration measurements at the catalytic reactor outlet show near-equilibrium conditions, the inhere presented temperature profile shows that it is insufficient to base a reaction mechanism development on close equilibrium data. The new experimental data allow for achieving much higher quality in the modeling efforts. Additionally, by carefully controlling the available active surface via dilution in the experiment, it was possible to slow down the catalyst conversion rate, which helped during the adjustment of the reaction kinetics. To assess the accuracy of the revised mechanism, a monolith experiment from the literature was simulated. The results show that the fitted reaction mechanism was able to accurately predict the experimental outcomes for various inlet mass flows, temperatures, and steam-to-carbon ratios.}, language = {en} } @misc{MaussMachalDelfauetal., author = {Mauß, Fabian and Machal, C. and Delfau, J.-L. and Vovelle, C. and Mor{\´e}ac, Gladys and Mounam-Rousselle, G.}, title = {Modelling of Aromatics and Soot Formation from Large Fuel Molecules}, series = {Proceedings of the Combustion Institute}, volume = {32}, journal = {Proceedings of the Combustion Institute}, number = {1}, issn = {0082-0784}, pages = {753 -- 760}, language = {en} } @misc{MaussAhmedZeuch, author = {Mauß, Fabian and Ahmed, Syed Sayeed and Zeuch, Thomas}, title = {The Generation of a Compact n-Heptane / Toluene Reaction Mechanism Using the Chemistry Guided Reduction (CGR) Technique}, series = {Zeitschrift f{\"u}r Physikalische Chemie}, volume = {223}, journal = {Zeitschrift f{\"u}r Physikalische Chemie}, number = {4-5}, issn = {0942-9352}, pages = {551 -- 563}, language = {en} } @misc{MaussHoffmeyerMontefrancescoetal., author = {Mauß, Fabian and Hoffmeyer, Henrik and Montefrancesco, Emanuela and Beck, Linda and Willand, J{\"u}rgen and Ziebert, Florian}, title = {CARE - Catalytic Reformated Exhaust gases in turbocharged DISI-Engines}, series = {SAE International Journal of Fuels and Lubricants}, volume = {2}, journal = {SAE International Journal of Fuels and Lubricants}, number = {1}, issn = {1946-3952}, pages = {139 -- 148}, language = {en} } @misc{MaussNakovWenzeletal., author = {Mauß, Fabian and Nakov, Galin and Wenzel, Paul and Steiner, R{\"u}diger and Kr{\"u}ger, Christian and Zhang, Yongzeh and Rawat, Rajesh and Borg, Andreas and Perlman, Cathleen and Fr{\"o}jd, Karin and Lehtiniemi, Harry}, title = {Soot Simulation under Diesel Engine Conditions Using a Flamelet Approach}, series = {SAE International Journal of Engines}, volume = {2}, journal = {SAE International Journal of Engines}, number = {2}, issn = {1946-3936}, pages = {89 -- 104}, language = {en} } @misc{MaussBlurockTuner, author = {Mauß, Fabian and Blurock, Edward S. and Tuner, Martin}, title = {Phase Optimized Skeletal Mechanisms for Engine Simulations}, series = {Combustion Theory and Modelling}, volume = {14}, journal = {Combustion Theory and Modelling}, number = {3}, issn = {1364-7830}, pages = {295 -- 313}, language = {en} } @misc{MaussLovasMalik, author = {Mauß, Fabian and L{\o}v{\aa}s, Terese and Malik, Nadeem}, title = {Global reaction mechanism for ethylene flames with preferential diffusion}, language = {en} } @misc{MaussMalikLovas, author = {Mauß, Fabian and Malik, Nadeem and L{\o}v{\aa}s, Terese}, title = {The Effect of Preferential Diffusion on the Soot Initiation Process in Ethylene Diffusion Flames}, series = {Flow Turbulence and Combustion}, volume = {87}, journal = {Flow Turbulence and Combustion}, number = {2-3}, issn = {1386-6184}, pages = {293 -- 312}, language = {en} } @misc{MaussFroejd, author = {Mauß, Fabian and Fr{\"o}jd, Karin}, title = {A three-parameter transient 1D model for catalyst modeling}, series = {SAE International Journal of Engines}, volume = {4}, journal = {SAE International Journal of Engines}, number = {1}, issn = {1946-3936}, pages = {1747 -- 1763}, language = {en} } @misc{OsswaldKohseHoeinghausStruckmeieretal., author = {Oßwald, Patrick and Kohse-H{\"o}inghaus, Katharina and Struckmeier, Ulf and Zeuch, Thomas and Seidel, Lars and Leon, Larisa and Mauß, Fabian}, title = {Combustion chemistry of the butane isomers in premixed low-pressure flames}, series = {Zeitschrift f{\"u}r Physikalische Chemie}, volume = {225}, journal = {Zeitschrift f{\"u}r Physikalische Chemie}, number = {9-10}, issn = {0942-9352}, pages = {1029 -- 1054}, language = {en} } @incollection{MaussSchmittSchneideretal., author = {Mauß, Fabian and Schmitt, Frank and Schneider, Kai and Bockhorn, Henning}, title = {"NO formation during Ignition of One Dimensional Laminar Flamelets"}, language = {en} } @incollection{MaussLovasSoyhan, author = {Mauß, Fabian and L{\o}v{\aa}s, Terese and Soyhan, H. S.}, title = {"Reduction of Complex Fuel Chemistry for Simulation of Combustion in a PSR-PFR reactor sequence"}, language = {en} } @article{MaussLovasAmneusetal., author = {Mauß, Fabian and L{\o}v{\aa}s, Terese and Amn{\´e}us, Per and Mastorakos, Epaminondas}, title = {"Comparison of Automatic Reduction Procedures for Ignition Chemistry"}, language = {en} } @article{MaussMaigaardKraft, author = {Mauß, Fabian and Maigaard, Peter and Kraft, M.}, title = {"Homogeneous Charge Compression Ignition Engine: A Simulation Study on the Effects of Inhomogenities"}, language = {en} } @misc{MaussHiltnerAgamaetal., author = {Mauß, Fabian and Hiltner, Joel D. and Agama, Rey and Johansson, Borje}, title = {"HCCI Operation with Natural Gas: Fuel Composition Implications"}, language = {en} } @misc{MaussKellerPeters, author = {Mauß, Fabian and Keller, D. and Peters, Norbert}, title = {A Lagrangian Simulation of Flamelet Extinction and Re-Ignition in Turbulent Jet Diffusion Flames}, series = {Symposium (International) on Combustion}, volume = {23}, journal = {Symposium (International) on Combustion}, number = {1}, issn = {0082-0784}, pages = {693 -- 698}, language = {en} } @misc{MaussSeshadriPetersetal., author = {Mauß, Fabian and Seshadri, K. and Peters, Norbert and Warnatz, J.}, title = {A Flamelet Calculation of Benzene Formation in Coflowing Laminar Diffusion Flames}, series = {Symposium (International) on Combustion}, volume = {23}, journal = {Symposium (International) on Combustion}, number = {1}, issn = {0082-0784}, pages = {559 -- 566}, language = {en} } @misc{MaussGoettgensPeters, author = {Mauß, Fabian and G{\"o}ttgens, J. and Peters, Norbert}, title = {Analytic Approximation of Burning Velocities and Flame Thickness of Lean Hydrogen, Methane, Ethylene, Acetylene and Propane Flames}, series = {Symposium (International) on Combustion}, volume = {24}, journal = {Symposium (International) on Combustion}, number = {1}, issn = {0082-0784}, pages = {129 -- 135}, language = {en} } @misc{MaussSchlegelBuseretal., author = {Mauß, Fabian and Schlegel, A. and Buser, S. and Benz, P. and Bockhorn, Henning}, title = {NOx Emissions of Catalytic Stabilized Combustion to Lean Premixed Combustion}, series = {Symposium (International) on Combustion}, volume = {25}, journal = {Symposium (International) on Combustion}, number = {1}, issn = {0082-0784}, pages = {1019 -- 1026}, language = {en} } @misc{MaussBockhorn, author = {Mauß, Fabian and Bockhorn, Henning}, title = {Soot Formation in Premixed Hydrocarbon Flames, Prediction of Temperature and Pressure Dependence}, series = {Zeitschrift f{\"u}r physikalische Chemie}, volume = {188}, journal = {Zeitschrift f{\"u}r physikalische Chemie}, number = {1/2}, issn = {0942-9352}, pages = {45 -- 60}, language = {en} } @misc{MaussLovasNilsson, author = {Mauß, Fabian and L{\o}v{\aa}s, Terese and Nilsson, D.}, title = {Automatic Reduction Procedure for Chemical Mechanisms Applied to Premixed Methane-Air Flames}, series = {Symposium (International) on Combustion}, volume = {28}, journal = {Symposium (International) on Combustion}, number = {2}, issn = {0082-0784}, pages = {1809 -- 1815}, language = {en} } @incollection{MaussTrevino, author = {Mauß, Fabian and Trevi{\~n}o, C.}, title = {"Structure and Extinction of Non-Diluted Hydrogen-Air Diffusion Flames"}, language = {en} } @incollection{MaussLindstedt, author = {Mauß, Fabian and Lindstedt, R. P.}, title = {"Reduced Kinetic Mechanisms for Acetylene Diffusion Flames"}, language = {en} } @incollection{MaussChungLeeetal., author = {Mauß, Fabian and Chung, S. H. and Lee, S. H. and Peters, Norbert}, title = {"Reduced Kinetic Mechanisms and NOx-Formation in Diffusion Flames of CH4 /C2H6 Mixtures"}, language = {en} } @inproceedings{MaussGoganSundenetal., author = {Mauß, Fabian and Gogan, Adina and Sund{\´e}n, Bengt and Montorsi, Luca and Akmed, S. S.}, title = {"Knock Modelling: An Integrated Tool for Detailed Chemistry and Engine Cycle Simulation"}, doi = {10.4271/2003-01-3122}, language = {en} } @misc{MaussBhaveKraftetal., author = {Mauß, Fabian and Bhave, Amit and Kraft, Markus and Montorsi, Luca}, title = {"Modelling a Dual-fuelled Multi-cylinder HCCI Engine Using a PDF based Engine Cycle Simulator"}, language = {en} } @inproceedings{MaussHajirezaSunden, author = {Mauß, Fabian and Hajireza, S. and Sund{\´e}n, Bengt}, title = {"Investigation of End-Gas Temperature and Pressure Increases in Gasoline Engines and its Relevance to Knock Occurrence"}, language = {en} } @inproceedings{MaussKarlssonMagnussonetal., author = {Mauß, Fabian and Karlsson, A. and Magnusson, I. and Balthasar, M.}, title = {"Simulation of Soot Formation under Diesel Engine Conditions Using a detailed Kinetic Soot Model"}, language = {en} } @inproceedings{MaussChristensenJohanssonetal., author = {Mauß, Fabian and Christensen, Magnus and Johansson, Bengt and Amn{\´e}us, Per}, title = {"Supercharged Homogeneous Charge Compression Ignition"}, language = {en} } @misc{MaussMosbachKraftetal., author = {Mauß, Fabian and Mosbach, Sebastian and Kraft, Markus and Bhave, Amit and Mack, John Hunter and Dibble, Robert W.}, title = {"Simulating a Homogeneous Charge Compression Ignition Engine Fuelled with a DEE/EtOH Blend"}, language = {en} } @inproceedings{MaussLehtiniemiZhangetal., author = {Mauß, Fabian and Lehtiniemi, Harry and Zhang, Y. and Rawat, Rajesh}, title = {"Efficient 3-D CFD Combustion Modeling with Transient Flamelet Models"}, language = {en} } @inproceedings{MaussPasternakBensler, author = {Mauß, Fabian and Pasternak, Michal and Bensler, H.}, title = {Diesel Engine Cycle Simulation with Reduced Set of Modeling Parameter Based on Detailed Kinetics}, language = {en} } @inproceedings{MaussEbenezerLehtiniemi, author = {Mauß, Fabian and Ebenezer, N. and Lehtiniemi, Harry}, title = {Adaptive Polynomial Tabulation (APT): A computationally economical strategy for the HCCI engine simulation of complex fuel}, language = {en} } @inproceedings{MaussTunerFroejdetal., author = {Mauß, Fabian and Tuner, Martin and Fr{\"o}jd, Karin and Seidel, Lars}, title = {"Diesel-PPC engine: Predictive Full Cycle Modeling with Reduced and Detailed Chemistry"}, language = {en} } @inproceedings{MaussFivelandChristensenetal., author = {Mauß, Fabian and Fiveland, Scott B. and Christensen, Magnus and Johansson, Bengt and Hiltner, Joel D. and Agama, Rey and Assanis, Dennis N.}, title = {"Experimental and Simulated Results Detailing the Sensitivity of Natural Gas HCCI Engines to Fuel Composition"}, doi = {10.4271/2001-01-3609}, language = {en} } @inproceedings{MaussLovasHasseetal., author = {Mauß, Fabian and L{\o}v{\aa}s, Terese and Hasse, C. and Peters, Norbert}, title = {"Modelling of HCCI Combustion using Adaptive Chemical Kinetics"}, language = {en} } @inproceedings{MaussCantoreMontorsietal., author = {Mauß, Fabian and Cantore, G. and Montorsi, Luca and Amn{\´e}us, Per and Erlandsson, O. and Johansson, B. and Morel, T.}, title = {"Analysis of a 6-Cylinder Turbocharged HCCI Engine Using A Detailed Kinetic Mechanism"}, language = {en} } @misc{GuentherMaussKlaueretal., author = {G{\"u}nther, Vivien and Mauß, Fabian and Klauer, Christian and Schlawitschek, Christiane}, title = {Kinetic Monte Carlo simulation of the epitaxial growth of Si(100)}, series = {Physica status solidi : C}, volume = {9}, journal = {Physica status solidi : C}, number = {10-11}, issn = {1610-1634}, pages = {1955 -- 1962}, language = {en} } @misc{GoosSickfeldMaussetal., author = {Goos, Elke and Sickfeld, Christina and Mauß, Fabian and Seidel, Lars and Ruscic, Branko and Burcat, Alexander and Zeuch, Thomas}, title = {Prompt NO formation in flames: The influence of NCN thermochemistry}, series = {Proceedings of the Combustion Institute}, volume = {Vol. 34}, journal = {Proceedings of the Combustion Institute}, issn = {1540-7489}, pages = {657 -- 666}, language = {en} } @misc{SeidelHoyermannMaussetal., author = {Seidel, Lars and Hoyermann, Karlheinz and Mauß, Fabian and Nothdurft, J{\"o}rg and Zeuch, Thomas}, title = {Pressure Dependent Product Formation in the Photochemically Initiated allyl + allyl reaction}, series = {Molecules}, volume = {18}, journal = {Molecules}, number = {11}, issn = {1420-3049}, pages = {13608 -- 13622}, language = {en} } @inproceedings{LehtiniemiMaussBalthasaretal., author = {Lehtiniemi, Harry and Mauß, Fabian and Balthasar, M. and Magnusson, I.}, title = {Diesel Spray Ignition using a Progress Variable Approach}, series = {Book of abstracts, Fifth Symposium Towards Clean Diesel Engines, 2 - 3 June 2005, Lund, Sweden}, booktitle = {Book of abstracts, Fifth Symposium Towards Clean Diesel Engines, 2 - 3 June 2005, Lund, Sweden}, publisher = {Univ., Lund Institute of Technology}, address = {Lund}, language = {en} } @misc{TunerPasternakMaussetal., author = {Tuner, Martin and Pasternak, Michal and Mauß, Fabian and Bensler, H.}, title = {A PDF-Based Model for Full Cycle Simulation of Direct Injected Engines}, series = {SAE Technical Papers}, journal = {SAE Technical Papers}, number = {2008-01-1606}, issn = {0096-5170}, abstract = {In one-dimensional engine simulation programs the simulation of engine performance is mostly done by parameter fitting in order to match simulations with experimental data. The extensive fitting procedure is especially needed for emissions formation - CO, HC, NO, soot - simulations. An alternative to this approach is, to calculate the emissions based on detailed kinetic models. This however demands that the in-cylinder combustion-flow interaction can be modeled accurately, and that the CPU time needed for the model is still acceptable. PDF based stochastic reactor models offer one possible solution. They usually introduce only one (time dependent) parameter - the mixing time - to model the influence of flow on the chemistry. They offer the prediction of the heat release, together with all emission formation, if the optimum mixing time is given. Hence parameter fitting for a number of kinetic processes, that depend also on the in cylinder flow conditions is replaced by a single parameter fitting for the turbulent mixing time. In this work a PDF based model was implemented and coupled to the full cycle engine simulation tool, WAVE, and calculations were compared to engine experiments. Modeling results show good agreement with the experiments and show that PDF based Dl models can be used for fast and accurate simulation of Dl engine emissions and performance.}, language = {en} } @inproceedings{AhmedMoreacZeuchetal., author = {Ahmed, Syed Sayeed and Mor{\´e}ac, Gladys and Zeuch, Thomas and Mauß, Fabian}, title = {Reduced Mechanism for the Oxidation of the Mixtures of n-Heptane and iso-Octane}, series = {Proceedings of the European Combustion Meeting, Louvain-la-Neuve, Belgium, April 3 - 6, 2005}, booktitle = {Proceedings of the European Combustion Meeting, Louvain-la-Neuve, Belgium, April 3 - 6, 2005}, publisher = {Combustion Inst.}, address = {Louvain-la-Neuve}, language = {en} } @inproceedings{GoganLehtiniemiMaussetal., author = {Gogan, Adina and Lehtiniemi, Harry and Mauß, Fabian and Sunden, Bengt}, title = {Stochastic Reactor Model for Auto-Ignition Calculation in Spark Ignition Engines}, series = {Proceedings of the European Combustion Meeting, Louvain-la-Neuve, Belgium, April 3 - 6, 2005}, booktitle = {Proceedings of the European Combustion Meeting, Louvain-la-Neuve, Belgium, April 3 - 6, 2005}, address = {Louvain-la-Neuve}, language = {en} } @phdthesis{Mauss, author = {Mauß, Fabian}, title = {Entwicklung eines kinetischen Modells der Rußbildung mit schneller Polymerisation}, publisher = {Cuvillier Verlag}, address = {G{\"o}ttingen}, isbn = {3-89712-152-2}, language = {de} } @inproceedings{PasternakMauss, author = {Pasternak, Michal and Mauß, Fabian}, title = {Simulation von Kraftstoffeffekten unter Dieselmotorischen Bedingungen mittels eines OD Kraftstoff-Versuchsstandes}, series = {Motorische Verbrennung, aktuelle Probleme und moderne L{\"o}sungsans{\"a}tze XI. Tagung im Haus der Technik e.V., Ludwigsburg, 14./15. M{\"a}rz 2013}, booktitle = {Motorische Verbrennung, aktuelle Probleme und moderne L{\"o}sungsans{\"a}tze XI. Tagung im Haus der Technik e.V., Ludwigsburg, 14./15. M{\"a}rz 2013}, editor = {Leipertz, Alfred}, publisher = {ESYTEC Energie- u. Systemtechnik}, address = {Erlangen}, isbn = {978-3-931901-87-5}, pages = {337 -- 346}, language = {de} } @inproceedings{LehtiniemiBorgMauss, author = {Lehtiniemi, Harry and Borg, Andreas and Mauß, Fabian}, title = {Konditionierte Momenten-Schließung mit einem Fortschritts-Variablen-Ansatz}, series = {Motorische Verbrennung, aktuelle Probleme und moderne L{\"o}sungsans{\"a}tze XI. Tagung im Haus der Technik e.V., Ludwigsburg, 14./15. M{\"a}rz 2013}, booktitle = {Motorische Verbrennung, aktuelle Probleme und moderne L{\"o}sungsans{\"a}tze XI. Tagung im Haus der Technik e.V., Ludwigsburg, 14./15. M{\"a}rz 2013}, editor = {Leipertz, Alfred}, publisher = {ESYTEC Energie- u. Systemtechnik}, address = {Erlangen}, isbn = {978-3-931901-87-5}, pages = {347 -- 358}, language = {de} } @incollection{LehtiniemiBorgMauss, author = {Lehtiniemi, Harry and Borg, Andreas and Mauß, Fabian}, title = {Conditional Moment Closure with a Progress Variable Approach}, series = {Engine processes}, booktitle = {Engine processes}, publisher = {Expert Verlag}, address = {Renningen}, isbn = {978-3-8169-3222-2}, pages = {100 -- 111}, language = {en} } @misc{SeidelMoshammerWangetal., author = {Seidel, Lars and Moshammer, Kai and Wang, Xiaoxiao and Zeuch, Thomas and Kohse-H{\"o}inghaus, Katharina and Mauß, Fabian}, title = {Comprehensive kinetic modeling and experimental study of a fuel-rich, premixed n-heptane flame}, series = {Combustion and Flame}, volume = {162}, journal = {Combustion and Flame}, number = {5}, issn = {0010-2180}, doi = {10.1016/j.combustflame.2015.01.002}, pages = {2045 -- 2058}, abstract = {An existing comprehensive kinetic hydrocarbon oxidation model has been augmented and revised for a detailed analysis of n-heptane flame chemistry. The analysis was enabled by experiments in which the detailed species composition in a fuel-rich flat premixed (ϕ=1.69) n-heptane flame at 40mbar has been studied by flame-sampling molecular-beam mass spectrometry using electron impact ionization. Mole fraction profiles of more than 80 different species have been measured and compared against the new detailed kinetic model consisting of 349 species and 3686 elementary reactions. For all major products and most of the minor intermediates, a good agreement of the modeling results with the experimentally-observed mole fraction profiles has been found. The presence of low- and intermediate-temperature chemistry close to the burner surface was consistently observed in the experiment and the simulation. With the same kinetic model, n-heptane auto-ignition timing, flame speeds and species composition in a jet-stirred reactor have been successfully simulated for a broad range of temperatures (500-2000K) and pressures (1-40bar). The comprehensive nature and wide applicability of the new model were further demonstrated by the examination of various target experiments for other C1 to C7 fuels.}, language = {en} } @inproceedings{MaussMatrisciano, author = {Mauß, Fabian and Matrisciano, Andrea}, title = {SRM in Engines: Performance and Emissions}, series = {3rd International Combustion Institute Summer School, June 19-23, Chania, Greece}, booktitle = {3rd International Combustion Institute Summer School, June 19-23, Chania, Greece}, language = {en} } @inproceedings{LeondeSyniawaNawdiyalSeideletal., author = {Leon de Syniawa, Larisa and Nawdiyal, A. and Seidel, Lars and Mauß, Fabian}, title = {Formation of C5 Species from iso-Butene}, series = {Book of Abstracts, SMARTCATs 2nd General Meeting \& Workshop on Smart Energy Carriers in Industry Lisbon, 14-16 November - 2016}, booktitle = {Book of Abstracts, SMARTCATs 2nd General Meeting \& Workshop on Smart Energy Carriers in Industry Lisbon, 14-16 November - 2016}, pages = {42 -- 43}, language = {en} } @inproceedings{FischerGuentherBergeretal., author = {Fischer, Michael and G{\"u}nther, Michael and Berger, Carsten and Troeger, Ralf and Pasternak, Michal and Mauß, Fabian}, title = {Suppressing Knocking by Using CleanEGR - Better Fuel Economy and Lower Raw Emissions Simultaneously}, series = {Knocking in Gasoline Engines, 5th International Conference, December 12-13, 2017, Berlin, Germany}, booktitle = {Knocking in Gasoline Engines, 5th International Conference, December 12-13, 2017, Berlin, Germany}, editor = {G{\"u}nther, Michael and Sens, Marc}, publisher = {Springer International Publishing}, address = {Cham}, isbn = {978-3-319-69760-4}, doi = {10.1007/978-3-319-69760-4_21}, pages = {384}, language = {en} } @inproceedings{PasternakNetzerMaussetal., author = {Pasternak, Michal and Netzer, Corinna and Mauß, Fabian and Fischer, Michael and Sens, Marc and Riess, Michael}, title = {Simulation of the Effects of Spark Timing and External EGR on Gasoline Combustion Under Knock-Limited Operation at High Speed and Load}, series = {Knocking in Gasoline Engines, 5th International Conference, December 12-13, 2017, Berlin, Germany}, booktitle = {Knocking in Gasoline Engines, 5th International Conference, December 12-13, 2017, Berlin, Germany}, editor = {G{\"u}nther, Michael and Sens, Marc}, publisher = {Springer International Publishing}, address = {Cham}, isbn = {978-3-319-69760-4}, doi = {10.1007/978-3-319-69760-4_8}, pages = {121 -- 142}, language = {en} } @inproceedings{AslanjanKlauerGuentheretal., author = {Aslanjan, Jana and Klauer, Christian and G{\"u}nther, Vivien and Mauß, Fabian}, title = {On the Influence of Inlet Gas Variations and Gas Phase Chemistry in a Three-Way Catalyst}, series = {COMODIA - The Ninth International Conference on Modeling and Diagnostics for Advanced, July 25, 2017 - July 28, 2017}, booktitle = {COMODIA - The Ninth International Conference on Modeling and Diagnostics for Advanced, July 25, 2017 - July 28, 2017}, doi = {10.1299/jmsesdm.2017.9.A308}, abstract = {The conversion effects of a three-way catalyst are simulated in previous works using single and multiple representative channel approaches with detailed surface kinetic models. In addition, this article introduces global gas phase chemistry to the model. This allows reflecting ongoing reactions due to incomplete combustion products in low temperature regime. The 1D single-channel model representative for the catalyst is used here. Next to the comparison of the catalyst outlet emissions with and without gas phase chemistry, the transient temperature increase is simulated in order to model the catalysts light off temperature. Additionally, the transient inlet emissions are enhanced to show the influence of water and hydrogen on the modeling results. The heat transfer is modeled by wall heat losses to provide proper heat dissipation out of the catalyst. The modeling results show a good agreement to the experimental data with low computational cost.}, language = {en} } @misc{FrankenKlauerKienbergetal., author = {Franken, Tim and Klauer, Christian and Kienberg, Martin and Matrisciano, Andrea and Mauß, Fabian}, title = {Prediction of thermal stratification in an engine-like geometry using a zero-dimensional stochastic reactor model}, series = {International Journal of Engine Research}, journal = {International Journal of Engine Research}, isbn = {2041-3149}, issn = {1468-0874}, doi = {10.1177/1468087418824217}, pages = {14}, language = {en} } @misc{SiddareddyFrankenPasternaketal., author = {Siddareddy, Reddy Babu and Franken, Tim and Pasternak, Michal and Leon de Syniawa, Larisa and Oder, Johannes and Rottengruber, Hermann and Mauß, Fabian}, title = {Real-Time Simulation of CNG Engine and After-Treatment System Cold Start. Part 1: Transient Engine-Out Emission Prediction Using a Stochastic Reactor Model}, series = {SAE Technical Paper}, journal = {SAE Technical Paper}, issn = {2688-3627}, doi = {10.4271/2023-01-0183}, abstract = {During cold start of natural gas engines, increased methane and formaldehyde emissions can be released due to flame quenching on cold cylinder walls, misfiring and the catalyst not being fully active at low temperatures. Euro 6 legislation does not regulate methane and formaldehyde emissions. New limits for these two pollutants have been proposed by CLOVE consortium for Euro 7 scenarios. These proposals indicate tougher requirements for aftertreatment systems of natural gas engines. In the present study, a zero-dimensional model for real-time engine-out emission prediction for transient engine cold start is presented. The model incorporates the stochastic reactor model for spark ignition engines and tabulated chemistry. The tabulated chemistry approach allows to account for the physical and chemical properties of natural gas fuels in detail by using a-priori generated laminar flame speed and combustion chemistry look-up tables. The turbulence-chemistry interaction within the combustion chamber is predicted using a K-k turbulence model. The optimum turbulence model parameters are trained by matching the experimental cylinder pressure and engine-out emissions of nine steady-state operating points. Subsequently, the trained engine model is applied for predicting engine-out emissions of a WLTP passenger car engine cold start. The predicted engine-out emissions comprise nitrogen oxide, carbon monoxide, carbon dioxide, unburnt methane, formaldehyde, and hydrogen. The simulation results are validated by comparing to transient engine measurements at different ambient temperatures (-7°C, 0°C, 8°C and 20°C). Additionally, the sensitivity of engine-out emissions towards air-fuel-ratio (λ=1.0 and λ=1.3) and natural gas quality (H-Gas and L-Gas) is investigated.}, language = {en} } @misc{LeondeSyniawaSiddareddyOderetal., author = {Leon de Syniawa, Larisa and Siddareddy, Reddy Babu and Oder, Johannes and Franken, Tim and G{\"u}nther, Vivien and Rottengruber, Hermann and Mauß, Fabian}, title = {Real-Time Simulation of CNG Engine and After-Treatment System Cold Start. Part 2: Tail-Pipe Emissions Prediction Using a Detailed Chemistry Based MOC Model}, series = {SAE Technical Report}, journal = {SAE Technical Report}, issn = {2688-3627}, doi = {10.4271/2023-01-0364}, abstract = {In contrast to the currently primarily used liquid fuels (diesel and gasoline), methane (CH4) as a fuel offers a high potential for a significant reduction of greenhouse gas emissions (GHG). This advantage can only be used if tailpipe CH4 emissions are reduced to a minimum, since the GHG impact of CH4 in the atmosphere is higher than that of carbon dioxide (CO2). Three-way catalysts (TWC - stoichiometric combustion) and methane oxidation catalysts (MOC - lean combustion) can be used for post-engine CH4 oxidation. Both technologies allow for a nearly complete CH4 conversion to CO2 and water at sufficiently high exhaust temperatures (above the light-off temperature of the catalysts). However, CH4 combustion is facing a huge challenge with the planned introduction of Euro VII emissions standard, where stricter CH4 emission limits and a decrease of the cold start starting temperatures are discussed. The aim of the present study is to develop a reliable kinetic catalyst model for MOC conversion prediction in order to optimize the catalyst design in function of engine operation conditions, by combining the outputs from the predicted transient engine simulations as inputs to the catalyst model. Model development and training has been performed using experimental engine test bench data at stoichiometric conditions as well as engine simulation data and is able to reliably predict the major emissions under a broad range of operating conditions. Cold start (-7°C and +20°C) experiments were performed for a simplified worldwide light vehicle test procedure (WLTP) driving cycle using a prototype gas engine together with a MOC. For the catalyst simulations, a 1-D catalytic converter model was used. The model includes detailed gas and surface chemistry that are computed together with catalyst heat up. In a further step, a virtual transient engine cold start cycle is combined with the MOC model to predict tail-pipe emissions at transient operating conditions. This method allows to perform detailed emission investigations in an early stage of engine prototype development.}, language = {en} } @inproceedings{ShresthaSeidelMaussetal., author = {Shrestha, Krishna Prasad and Seidel, Lars and Mauß, Fabian and Zeuch, Thomas}, title = {Development of a kinetic mechanism for NOx fuel interaction}, series = {Proceedings, Joint Meeting of the German and Italian Sections of the Combustion Institute, 41st Meeting on Combustion, Sorrento, May 2018}, booktitle = {Proceedings, Joint Meeting of the German and Italian Sections of the Combustion Institute, 41st Meeting on Combustion, Sorrento, May 2018}, editor = {Bockhorn, Henning and Scala, F. and Commodo, M. and Tregrossi, A.}, publisher = {Associazione Sezione Italiana del Combustion Institute}, address = {Napoli}, isbn = {978-88-88104-22-5}, pages = {6}, abstract = {This work introduces a newly developed reaction mechanism to predict fuel/NOx interaction in freely propagating, burner stabilized premixed flames, shock tubes, jet stirred reactors and plug flow reactors experiments. The study focuses on pure ammonia as fuel as well as H₂,H₂/CO, CH₄ doped with NO, NO₂ and N₂O. The kinetic scheme also focuses on the formation and consumption of nitrogen oxides at different experimental conditions. It is found that the doping with N₂O has almost no sensitivity on the H₂ chemistry, while small amount of NO₂ is enough to change the pressure dependence of H₂ auto ignition. The experiments with N₂O still show the significant influence of the chain breaking reaction H+O₂(+M)⇋HO₂(+M) on the H₂ ignition delay times, resulting in the crossing lines for the ignition delay times, which are moved at higher pressure to higher temperature. The concentration of HO₂ is decisive for the active reaction pathway in shock tube oxidation as well as in jet stirred and flow reactor. Reaction NO+HO₂⇋NO₂+OH and NO₂+H⇋NO+OH are very important because they strongly influence the inter conversion process of NO and NO₂ in jet stirred reactor and flow reactor for cases studied herein. The formation of NO in burner stabilized premixed flames is shown to demonstrate the capability of the mechanism to be integrated into mechanisms for hydrocarbon oxidation.}, language = {en} } @inproceedings{NetzerSeidelLehtiniemietal., author = {Netzer, Corinna and Seidel, Lars and Lehtiniemi, Harry and Ravet, Fr{\´e}d{\´e}ric and Mauß, Fabian}, title = {Impact of gasoline surrogates with different fuel sensitivity (RON-MON) on knock prediction}, series = {Proceedings of the 6th European Conference on Computational Mechanics (Solids, Structures and Coupled Problems) ECCM 6 and 7th European Conference on Computational Fluid Dynamics ECFD 7, Glasgow, Scotland, UK June 11 - 15, 2018}, booktitle = {Proceedings of the 6th European Conference on Computational Mechanics (Solids, Structures and Coupled Problems) ECCM 6 and 7th European Conference on Computational Fluid Dynamics ECFD 7, Glasgow, Scotland, UK June 11 - 15, 2018}, pages = {906 -- 917}, language = {en} } @inproceedings{FrankenNetzerPasternaketal., author = {Franken, Tim and Netzer, Corinna and Pasternak, Michal and Mauß, Fabian and Seidel, Lars and Matrisciano, Andrea and Borg, Anders and Lehtiniemi, Harry and Kulzer, Andr{\´e} Casal}, title = {Assessment of Water Injection in a SI Engine using a Fast Running Detailed Chemistry Based Combustion Model}, series = {Symposium of Combustion Control 2018, Aachen}, booktitle = {Symposium of Combustion Control 2018, Aachen}, address = {Aachen}, pages = {10}, language = {en} } @inproceedings{FrankenDugganFengetal., author = {Franken, Tim and Duggan, Alexander and Feng, Tao and Mauß, Fabian}, title = {Multi-Objective Optimization of Fuel Consumption and NOx Emissions for a Heavy-Duty Direct Injection Diesel Engine}, series = {European ESTECO User Meeting 2018, Trieste, Italy}, booktitle = {European ESTECO User Meeting 2018, Trieste, Italy}, language = {en} } @inproceedings{NetzerSeidelLehtiniemietal., author = {Netzer, Corinna and Seidel, Lars and Lehtiniemi, Harry and Ravet, Fr{\´e}d{\´e}ric and Mauß, Fabian}, title = {Impact of Formulation of Fuel Surrogates on Engine Knock Prediction}, series = {International Multidimensional Engine Modeling User's Group Meeting at the SAE Congress, April 9th , 2018, Detroit, USA}, booktitle = {International Multidimensional Engine Modeling User's Group Meeting at the SAE Congress, April 9th , 2018, Detroit, USA}, pages = {6}, language = {en} } @inproceedings{ShresthaSeidelMauss, author = {Shrestha, Krishna Prasad and Seidel, Lars and Mauß, Fabian}, title = {Kinetic study of methanol and ethanol oxidation in presence of NOx}, series = {Workshop on Gas-phase reaction kinetics of biofuels oxygenated molecules}, booktitle = {Workshop on Gas-phase reaction kinetics of biofuels oxygenated molecules}, language = {en} } @misc{LeondeSyniawaSiddareddyPrehnetal., author = {Leon de Syniawa, Larisa and Siddareddy, Reddy Babu and Prehn, Sascha and G{\"u}nther, Vivien and Franken, Tim and Buchholz, Bert and Mauß, Fabian}, title = {Simulation of CNG Engine in Agriculture Vehicles. Part 2: Coupled Engine and Exhaust Gas Aftertreatment Simulations Using a Detailed TWC Model}, series = {SAE Technical Paper}, journal = {SAE Technical Paper}, issn = {0148-7191}, doi = {10.4271/2023-24-0112}, abstract = {In more or less all aspects of life and in all sectors, there is a generalized global demand to reduce greenhouse gas (GHG) emissions, leading to the tightening and expansion of existing emissions regulations. Currently, non-road engines manufacturers are facing updates such as, among others, US Tier 5 (2028), European Stage V (2019/2020), and China Non-Road Stage IV (in phases between 2023 and 2026). For on-road applications, updates of Euro VII (2025), China VI (2021), and California Low NOx Program (2024) are planned. These new laws demand significant reductions in nitrogen oxides (NOx) and particulate matter (PM) emissions from heavy-duty vehicles. When equipped with an appropriate exhaust aftertreatment system, natural gas engines are a promising technology to meet the new emission standards. Gas engines require an appropriate aftertreatment technology to mitigate additional GHG releases as natural gas engines have challenges with methane (CH4) emissions that have 28 times more global warming potential compared to CO2. Under stoichiometric conditions a three-way catalytic converter (TWC - stoichiometric combustion) can be used to effectively reduce emissions of harmful pollutants such as nitrogen oxides and carbon monoxide (CO) as well as GHG like methane. The aim of the present study is to understand the performance of the catalytic converter in function of the engine operation and coolant temperature in order to optimize the catalyst operating conditions. Different cooling temperatures are chosen as the initial device temperature highly affects the level of warm up emissions such that low coolant temperatures entail high emissions. In order to investigate the catalyst performance, experimental and virtual transient engine emissions are coupled with a TWC model to predict tail-pipe emissions at transient operating conditions. Engine experiments are conducted at two initial engine coolant temperatures (10°C and 25°C) to study the effects on the Non-Road Transient Cycle (NRTC) emissions. Engine simulations of combustion and emissions with acceptable accuracy and with low computational effort are developed using the Stochastic Reactor Model (SRM). Catalyst simulations are performed using a 1D catalytic converter model including detailed gas and surface chemistry. The initial section covers essential aspects including the engine setup, definition of the engine test cycle, and the TWC properties and setup. Subsequently, the study introduces the transient SI-SRM, 1D catalyst model, and kinetic model for the TWC. The TWC model is used for the validation of a NRTC at different coolant temperatures (10°C and 25°C) during engine start. Moving forward, the next section includes the coupling of the TWC model with measured engine emissions. Finally, a virtual engine parameter variation has been performed and coupled with TWC simulations to investigate the performance of the engine beyond the experimental campaign. Various engine operating conditions (lambda variation for this paper) are virtually investigated, and the performance of the engine can be extrapolated. The presented virtual development approach allows comprehensive emission evaluations during the initial stages of engine prototype development}, language = {en} } @misc{SiddareddyFrankenLeondeSyniawaetal., author = {Siddareddy, Reddy Babu and Franken, Tim and Leon de Syniawa, Larisa and Pasternak, Michal and Prehn, Sascha and Buchholz, Bert and Mauß, Fabian}, title = {Simulation of CNG Engine in Agriculture Vehicles. Part 1: Prediction of Cold Start Engine-Out Emissions Using Tabulated Chemistry and Stochastic Reactor Model}, series = {SAE Technical Paper}, journal = {SAE Technical Paper}, issn = {0148-7191}, doi = {10.4271/2023-24-0006}, abstract = {Worldwide, there is the demand to reduce harmful emissions from non-road vehicles to fulfill European Stage V+ and VI (2022, 2024) emission legislation. The rules require significant reductions in nitrogen oxides (NOx), methane (CH4) and formaldehyde (CH2O) emissions from non-road vehicles. Compressed natural gas (CNG) engines with appropriate exhaust aftertreatment systems such as threeway catalytic converter (TWC) can meet these regulations. An issue remains for reducing emissions during the engine cold start where the CNG engine and TWC yet do not reach their optimum operating conditions. The resulting complexity of engine and catalyst calibration can be efficiently supported by numerical models. Hence, it is required to develop accurate simulation models which can predict cold start emissions. This work presents a real-time engine model for transient engine-out emission prediction using tabulated chemistry for CNG. The engine model is based on a stochastic reactor model (SRM) which describes the in-cylinder processes of spark ignition (SI) engines including large-scale and lowscale turbulence, convective heat transfer, turbulent flame propagation and chemistry. Chemistry is described using a tabulated chemistry model which calculates the major exhaust gas emissions of CNG engines such as CO2, NOx, CO, CH4 and CH2O. By best practice, the engine model parameters are optimized by matching the experimental cylinder pressure and engine-out emissions from steady-state operating points. The engine model is trained for a non-road transient cycle (NRTC) cold start at 25°C ambient temperature and validated for a NRTC cold start at 10°C ambient temperature. The trained model is evaluated regarding their feasibility and accuracy predicting transient engineout emissions.}, language = {en} } @misc{IssayevGiriElbazetal., author = {Issayev, Gani and Giri, Binod Raj and Elbaz, Ayman M. and Shrestha, Krishna Prasad and Mauß, Fabian and Roberts, William L. and Farooq, Aamir}, title = {Ignition delay time and laminar flame speed measurements of ammonia blended with dimethyl ether: A promising low carbon fuel blend}, series = {Renewable Energy}, volume = {181}, journal = {Renewable Energy}, issn = {1879-0682}, doi = {10.1016/j.renene.2021.09.117}, pages = {1353 -- 1370}, abstract = {Ammonia (NH3) has recently received much attention as a promising future fuel for mobility and power generation. The use of ammonia as a fueling vector can help curb global warming by cutting CO2 emissions because it is a carbon-free fuel and a hydrogen carrier with a high percentage of hydrogen atoms per unit volume. Liquid ammonia contains a higher volumetric density of hydrogen than liquid hydrogen. The low reactivity of ammonia, however, hinders its direct usage as a combustible fuel. One feasible way to boost the reactivity of ammonia is to target a dual-fuel system comprising of ammonia and a suitable combustion promoter. In this work, combustion properties of ammonia were investigated by blending it with various proportions of dimethyl ether (DME) using a rapid compression machine (RCM) and a constant volume spherical reactor (CVSR) over a wide range of experimental conditions. DME is a highly reactive fuel that may be produced in a sustainable carbon cycle with a net zero-carbon emission. Ignition delay times (IDTs) of NH3/DME blends were measured over a temperature (T) range of 649e950 K, pressures (P) of 20 and 40 bar, equivalence ratios (F) of 0.5 and 1 for a range of DME mole fractions (cDME) of 0.05e0.5 in the blends. In addition, the laminar burning velocities of NH3/DME blends were measured at P ¼ 1, 3 and 5 bar, F ¼ 0.8e1.3 and T ¼ 300 K for cDME ranging from 0.18 to 0.47. Our results suggest that DME is a good ignition promoter, resulting in a significant shortening of IDTs and an increase of flame speeds of NH3. A detailed chemical model has been developed and validated against the experimental data. Overall, our kinetic model offered reasonable predictive capabilities capturing the experimental trends over a wide range of conditions. In the worst-case scenario, our model underpredicted IDTs by a factor of ~2.5 while overpredicting laminar flame speed by ~20\%.}, language = {en} } @misc{ShresthaGiriElbazetal., author = {Shrestha, Krishna Prasad and Giri, Binod Raj and Elbaz, Ayman M. and Issayev, Gani and Roberts, William L. and Seidel, Lars and Mauß, Fabian and Farooq, Aamir}, title = {A detailed chemical insights into the kinetics of diethyl ether enhancing ammonia combustion and the importance of NOx recycling mechanism}, series = {Fuel Communications}, volume = {10}, journal = {Fuel Communications}, issn = {2666-0520}, doi = {10.1016/j.jfueco.2022.100051}, pages = {18}, abstract = {In this work, we investigated the combustion characteristics of ammonia (NH3) by blending it with various proportions of diethyl ether (DEE). We measured laminar flame speed of various NH3/DEE blends (DEE, 10-40\% by mole) using a constant volume spherical vessel at Ti = 298 K and Pi = 3 and 5 bar and Φ = 0.8-1.3. We developed a detailed kinetic model to describe the trends of the current and previously published experimental data. For the robustness of the model, we first developed a comprehensive diethyl ether kinetic mechanism to accurately characterize neat DEE oxidation behavior. We validated the kinetic model using a large pool of experimental data comprising shock tube, rapid compression machine, jet-stirred and flow reactors, freely propagating, and burner-stabilized premixed flames. The developed kinetic model performs remarkably in capturing the combustion behavior of pure DEE and NH3. Importantly, our model captures the experimental data of laminar flame speed and ignition delay times of various NH3/DEE blends over a wide range of conditions. We found that DEE is a promising candidate to promote the combustion characteristics of NH3. A small portion of DEE (10\%) enhances the laminar flame speed of NH3 by a factor of 2 at Pi = 1 bar, Ti = 298 K, and Φ = 1.0. A further doubling of the DEE mole fraction to 20\% did not enhance the laminar flame speed of NH3 with the same propensity. At low temperatures, adding 5\% DEE in NH3 blend has significantly expedited the system reactivity by lowering the autoignition temperature. A further 5\% increment of DEE (i.e., 10\% DEE in NH3) lowers the autoignition temperature by ∼120 K to achieve the same ignition delay time. The "NOsingle bondNO2" looping mechanism predominantly drives such reactivity accelerating effect. Here, the reactions, NO + HO2 = NO2 + OH and NO2 + H = NO + OH, appear to enhance the reactive radical pool by generating OH radicals. We observed that the HNO path is favored more with increasing DEE content which eventually liberates NO. Other key reactions in "NOsingle bondNO2" looping mechanism are: CH3 + NO2 = CH3O + NO, CH3O2 + NO = CH3O + NO2, C2H5 + NO2 = C2H5O + NO, C2H5O2 + NO = C2H5O + NO2. In addition, CH3 + NH2(+M) = CH3NH2(+M) reaction is also one of the important cross-reactions which leads to the formation of HCN. Therefore, cross-reactions between the nitrogen and carbon family are crucial in accurately predicting autoignition timing. This work provides a detailed chemical insight into the NH3 and DEE interaction, which could be applied to other fuel blends of NH3. The kinetic model is also validated for several C1single bondC3 fuels including their interaction with NOx.}, language = {en} } @misc{FrankenSrivastavaLeeetal., author = {Franken, Tim and Srivastava, Vivek and Lee, Sung-Yong and Heuser, Benedikt and Shrestha, Krishna Prasad and Seidel, Lars and Mauß, Fabian}, title = {Numerical Analysis of the Combustion of Diesel, Dimethyl Ether, and Polyoxymethylene Dimethyl Ethers (OMEn, n=1-3) Using Detailed Chemistry}, series = {THIESEL 2022 : Conference on Thermo- and Fluid-Dynamics of Clean Propulsion Powerplants, 13th-16th September 2022 : conference proceedings}, journal = {THIESEL 2022 : Conference on Thermo- and Fluid-Dynamics of Clean Propulsion Powerplants, 13th-16th September 2022 : conference proceedings}, editor = {Xandra, Margot and Payri, Ra{\´u}l and Serrano, Jos{\´e} Ram{\´o}n}, publisher = {Editorial Universitat Polit{\`e}cnica de Val{\`e}ncia}, address = {Val{\`e}ncia}, isbn = {978-84-1396-055-5}, doi = {10.4995/Thiesel.2022.632801}, abstract = {New types of synthetic fuels are introduced in internal combustion engine applications to achieve carbon-neutral and ultra-low emission combustion. Dimethyl Ether (DME) and Polyoxymethylene Dimethyl Ethers (OMEn) belong to such kind of synthetic fuels. Recently, Shrestha et al. (2022) have developed a novel detailed chemistry model for OMEn (n=1-3) to predict the ignition delay time, laminar flame speed and species formation for various thermodynamic conditions. The detailed chemistry model is applied in the zero dimensional (0D) stochastic reactor model (DI-SRM) to investigate the non-premixed combustion in a 2-liter diesel engine. Further insights in the formation of unburned hydrocarbons (HC), carbon monoxide and nitrogen oxides during the combustion of OMEn fuels are obtained in this work. The combustion and emission formation of DME and OMEn (n=1-3) are investigated and compared to conventional Diesel combustion. The mixture formation is governed by an earlier vaporization of the DME and OMEn fuels, faster homogenization of the respective air-fuel mixture and higher reactivity. At the same injection pressure, the OMEn fuels obtain higher NOx but lower CO and HC emissions. High amounts of aromatics, ethene, methane formaldehyde and formic acid are found within the Diesel exhaust gas. The DME and OMEn exhaust gas contains higher fractions of formaldehyde and formic acid, and fractions of methane, methyl formate and nitromethane.}, language = {en} } @misc{PicernoLeePasternaketal., author = {Picerno, Mario and Lee, Sung-Yong and Pasternak, Michal and Siddareddy, Reddy Babu and Franken, Tim and Mauß, Fabian and Andert, Jakob}, title = {Real-Time Emission Prediction with Detailed Chemistry under Transient Conditions for Hardware-in-the-Loop Simulations}, series = {Energies}, volume = {15}, journal = {Energies}, number = {1}, issn = {1996-1073}, doi = {10.3390/en15010261}, pages = {1 -- 21}, abstract = {The increasing requirements to further reduce pollutant emissions, particularly with regard to the upcoming Euro 7 (EU7) legislation, cause further technical and economic challenges for the development of internal combustion engines. All the emission reduction technologies lead to an increasing complexity not only of the hardware, but also of the control functions to be deployed in engine control units (ECUs). Virtualization has become a necessity in the development process in order to be able to handle the increasing complexity. The virtual development and calibration of ECUs using hardware-in-the-loop (HiL) systems with accurate engine models is an effective method to achieve cost and quality targets. In particular, the selection of the best-practice engine model to fulfil accuracy and time targets is essential to success. In this context, this paper presents a physically- and chemically-based stochastic reactor model (SRM) with tabulated chemistry for the prediction of engine raw emissions for real-time (RT) applications. First, an efficient approach for a time-optimal parametrization of the models in steady-state conditions is developed. The co-simulation of both engine model domains is then established via a functional mock-up interface (FMI) and deployed to a simulation platform. Finally, the proposed RT platform demonstrates its prediction and extrapolation capabilities in transient driving scenarios. A comparative evaluation with engine test dynamometer and vehicle measurement data from worldwide harmonized light vehicles test cycle (WLTC) and real driving emissions (RDE) tests depicts the accuracy of the platform in terms of fuel consumption (within 4\% deviation in the WLTC cycle) as well as NOx and soot emissions (both within 20\%).}, language = {en} } @misc{FritscheShresthaEckartetal., author = {Fritsche, Chris and Shrestha, Krishna Prasad and Eckart, Sven and Mauß, Fabian and Krause, Hartmut}, title = {Temperature and pressure dependency of the burning velocity in laminar premixed methanol and polyoxymethylene dimethyl ether (OME1, OME2, and OME3) flames}, series = {10th European Combustion Meeting, Proceedings of the European Combustion Meeting}, journal = {10th European Combustion Meeting, Proceedings of the European Combustion Meeting}, abstract = {This work reports the laminar burning velocities (LBV) for the liquid fuels methanol, and polyoxymethylene dimethyl ethers (OMEn, n = 1-3) in mixtures with air utilizing the heat flux burner and constant volume chamber at temperature 393 to 443 K, pressure 1 to 10 bar, and equivalence ratio 0.6 to 1.9. Laminar burning velocities for OME2 and OME3 higher than 1 bar are reported for the first time. A detailed chemical kinetic model for OME2 and OME3 was developed based on our previous work utilizing experimental data from this work. Overall, model predictions are in good agreement with the experimental data. It is previously shown that with increases in unburned gas temperature laminar burning velocity increases and shows a linear trend with respect to temperature. Further, laminar burning velocity decreases with an increase of initial pressure. The dependence of burning velocity is not linear for all the fuels investigated. For comparable temperature and pressure conditions, it was found that with an additional CH2O group the laminar burning velocities increase marginally and there is no shift of maximum laminar burning velocity with respect to equivalence ratio.}, language = {en} } @misc{FritscheEckartShresthaetal., author = {Fritsche, Chris and Eckart, Sven and Shrestha, Krishna Prasad and Mauß, Fabian and Krause, Hartmut}, title = {Methane flames with a substitution of 50 to 100 percent hydrogen: Experimental and numerical investigation of the temperature and pressure dependence of the laminar burning velocities}, series = {10th European Combustion Meeting, Proceedings of the European Combustion Meeting}, journal = {10th European Combustion Meeting, Proceedings of the European Combustion Meeting}, abstract = {This work reports the laminar burning velocities for CH4/H2 blends in mixtures with air utilizing the constant volume chamber at temperatures from 300 to 423 K, pressures from 2 to 10 bar and equivalence ratios from 0.7 to 2.4. A detailed chemical kinetic model based on our previous work is used to reproduce the experimental data. The chemical kinetic model can reproduce the experimental data better at lean conditions compared to rich conditions. It is observed that with an increase in H2 fraction in fuel blend, laminar burning velocities increase. Model reveals that with increasing H2 fraction in the fuel blend, formation of key radicals H, OH and O are promoted leading to higher laminar burning velocities. The most sensitive reactions are O2+H=OH+O, CO+OH=CO2+H, CH4+H=CH3+H2 and CH4+OH=CH3+H2O. It is found that as initial mixture temperature increases, the laminar burning velocity increases and shows a linear trend whereas this trend is reversed as the initial pressure increases.}, language = {en} } @misc{ShresthaGiriSeideletal., author = {Shrestha, Krishna Prasad and Giri, Binod Raj and Seidel, Lars and Farooq, Aamir and Mauß, Fabian}, title = {A Kinetic Modeling Study for the Effect of NOx on Oxymethylene ethers (OMEn, n = 0 and 1) oxidation}, series = {10th European Combustion Meeting, Neapel}, journal = {10th European Combustion Meeting, Neapel}, address = {Neapel}, abstract = {We present a detailed kinetic model for the oxidation of dimethyl ether (OME0) and dimethoxymethane (OME1) in presence of NOx. We further explored the effect of NOx chemistry on the oxidation kinetics of the two OMEs. Our kinetic model is validated against the recent flow reactor data from Zhang et al. (Combust. Flame. 224 (2021) 94- 107). The results indicated that NO doping severely alters the oxidation kinetics of both fuels. The onset temperature for total fuel consumption is significantly shifted to lower temperatures for both fuels, which is in line with the experimental observation. We found that the addition of NO significantly inhibited the NTC behaviour of dimethyl ether. This inhibiting effect appears to stem from the competition between CH3OCH2O2 radical consumption by NO directly and the isomerization/dissociation reactions of CH3OCH2O2. Unlike dimethyl ether, dimethoxymethane does not exhibit a strong NTC behavior, and NO addition completely inhibited its weak NTC behavior.}, language = {en} } @misc{FrankenMatriscianoSarietal., author = {Franken, Tim and Matrisciano, Andrea and Sari, Rafael and Robles, Alvaro Fogue and Monsalve-Serrano, Javier and Pintor, Dario Lopez and Pasternak, Michal and Garcia, Antonio and Mauß, Fabian}, title = {Modeling of Reactivity Controlled Compression Ignition Combustion Using a Stochastic Reactor Model Coupled with Detailed Chemistry}, series = {SAE technical papers : 15th International Conference on Engines \& Vehicles}, journal = {SAE technical papers : 15th International Conference on Engines \& Vehicles}, issn = {0148-7191}, doi = {10.4271/2021-24-0014}, pages = {18}, abstract = {Advanced combustion concepts such as reactivity controlled compression ignition (RCCI) have been proven to be capable of fundamentally improve the conventional Diesel combustion by mitigating or avoiding the soot-NOx trade-off, while delivering comparable or better thermal efficiency. To further facilitate the development of the RCCI technology, a robust and possibly computationally efficient simulation framework is needed. While many successful studies have been published using 3D-CFD coupled with detailed combustion chemistry solvers, the maturity level of the 0D/1D based software solution offerings is relatively limited. The close interaction between physical and chemical processes challenges the development of predictive numerical tools, particularly when spatial information is not available. The present work discusses a novel stochastic reactor model (SRM) based modeling framework capable of predicting the combustion process and the emission formation in a heavy-duty engine running under RCCI combustion mode. The combination of physical turbulence models, detailed emission formation sub-models and stateof-the-art chemical kinetic mechanisms enables the model to be computationally inexpensive compared to the 3D-CFD approaches. A chemical kinetic mechanism composed of 248 species and 1428 reactions was used to describe the oxidation of gasoline and diesel using a primary reference fuel (PRF)mixture and n-heptane, respectively. The model is compared to operating conditions from a single-cylinder research engine featuring different loads, speeds, EGR and gasoline fuel fractions. The model was found to be capable of reproducing the combustion phasing as well as the emission trends measured on the test bench, at some extent. The proposed modeling approach represents a promising basis towards establishing a comprehensive modeling framework capable of simulating transient operation as well as fuel property sweeps with acceptable accuracy.}, language = {en} } @misc{FrankenShresthaSeideletal., author = {Franken, Tim and Shrestha, Krishna Prasad and Seidel, Lars and Mauß, Fabian}, title = {Effect of Gasoline-Ethanol-Water Mixtures on Auto-Ignition in a Spark Ignition Engine}, series = {International Conference on Knocking in Gasoline Engines}, journal = {International Conference on Knocking in Gasoline Engines}, editor = {Sens, Marc}, publisher = {expert}, address = {T{\"u}bingen}, isbn = {978-3-8169-3544-5}, doi = {10.24053/9783816985440}, pages = {175 -- 222}, abstract = {The climate protection plan of the European Union requires a significant reduction of CO2 emissions from the transportation sector by 2030. Today ethanol is already blended by 10vol-\% in gasoline and further increase of the ethanol content to 20vol-\% is discussed. During the ethanol production process, distillation and molecular sieving is required to remove the water concentration to achieve high-purity ethanol. However, hydrous ethanol can be beneficial to suppress knock of spark ignition engines. The hygroscopic nature of ethanol can allow to increase the water content in gasoline - water emulsions even more, without adding additional surfactants, and improve the thermal efficiency by optimized combustion phasing, while keeping the system complexity low. Hence, the effect of gasoline - ethanol - water mixtures on the auto-ignition in a single-cylinder spark ignition engine is investigated by using multi-dimensional simulation and detailed chemistry. The gasoline - ethanol mixtures are defined to keep the Research Octane Number constant, while the Motored Octane Number is decreasing. In total five surrogates are defined and investigated: E10 (10vol-\% ethanol-in-gasoline), E20, E30, E70 and E100. The water content is determined according to experimentally defined ternary diagrams that evaluated stable gasoline - ethanol - water emulsion at different gasoline - ethanol blending ratios. The auto-ignition modes of the surrogates are analyzed using the diagram, which determines if hotspots are within harmless deflagration or harmful developing detonation regime. The strongest auto-ignition is observed for the E10 surrogate, while increasing ethanol content reduces the surrogate reactivity and increases the resonance parameter. No auto-ignition of the unburnt mixture is observed for the E70 and E100 surrogates. The addition of hydrous ethanol decreased the excitation time of the surrogates, especially at low ethanol content, wherefor the reactivity parameter is significantly increased. The hotspots for E10, E20 and E30 surrogates with hydrous ethanol are found within the developing detonation regime, while hotspots of the E70 surrogate with hydrous ethanol are found in the transition regime. For the hydrous E100 surrogate no auto-ignition is predicted because of reduced temperature of the unburnt mixture due to water vaporization, which outweighs the increased reactivity due to water vapor addition.}, language = {en} } @inproceedings{AslanjanKlauerGuentheretal., author = {Aslanjan, Jana and Klauer, Christian and Guenther, Vivien and Mauß, Fabian}, title = {Simulation of a three-way catalyst using a transient multi-channel model}, series = {Digital Proceedings of the 8th European Combustion Meeting (ECM 2017), Dubrovnik, Croatia}, booktitle = {Digital Proceedings of the 8th European Combustion Meeting (ECM 2017), Dubrovnik, Croatia}, address = {Dubrovnik}, pages = {570 -- 574}, abstract = {The conversion effects of a three-way catalyst (TWC) are simulated in previous works using single-channel approaches and detailed kinetic models. In addition to the single-channel model multiple representative catalyst channels are used in this work to take heat transfer between the channels into account. Furthermore, different inlet temperature distributions are considered and tested. An experimental four-stroke engine setup with emission outputs fed into a TWC is used to validate the model. Furthermore, the temperature progress is simulated to reflect the catalyst's light off temperature. Heat conduction between the channels is modeled to provide proper heat dissipation during the catalytic process. A good agreement to the experimental data can be achieved with low computational cost.}, language = {en} } @misc{FrankenSeidelShresthaetal., author = {Franken, Tim and Seidel, Lars and Shrestha, Krishna Prasad and Gonzalez Mestre, Laura Catalina and Mauß, Fabian}, title = {Multi-objective Optimization of Gasoline, Ethanol, and Methanol in Spark Ignition Engines}, abstract = {In this study, an engine and fuel co-optimization is performed to improve the efficiency and emissions of a spark ignition engine utilizing detailed reaction mechanisms and stochastic combustion modelling. The reaction mechanism for gasoline surrogates (Seidel 2017), ethanol, and methanol (Shrestha et al. 2019) is validated for experiments at different thermodynamic conditions. Liquid thermophysical properties of the RON95E10 surrogate (iso-octane, n-heptane, toluene, and ethanol mixture), ethanol, and methanol are determined using the NIST standard reference database (NIST 2018) and Yaws database (Yaws 2014). The combustion chemistry, laminar flame speed, and thermophysical data are pre-compiled in look-up tables to speed up the simulations (tabulated chemistry). The auto-ignition in the stochastic reactor model is predicted by the detailed chemistry and subsequently evaluated using the Bradley Detonation Diagram (Bradley et al. 2002, Gu et al. 2003, Neter 2019), which assigns two dimensionless parameters (resonance parameter and reactivity parameter). According to the defined developing detonation limits, the auto-ignition is either in deflagration, sub-sonic auto-ignition, or developing detonation mode. Ethanol and methanol show a knock-reducing characteristic, which is mainly due to the high heat of vaporization. The multi-objective optimization process includes mathematical algorithms for design space exploration with Uniform Latin Hypercube, pareto front convergence with Non-dominated Sorting Genetic Algorithm II (NSGA-II), and multi-criteria decision making (Deb et al. 2002). The optimization input parameter ranges are selected according to the previous sensitivity analysis, and the objectives are to minimize specific CO2 and specific CO and maximize indicated efficiency. The performance study of different optimization algorithms shows that the incorporation of metamodels is beneficial to improve the design space exploration, while keeping the optimization duration low. The comparison of different reaction mechanisms, which are applied in the optimization process, shows a strong impact on the pareto front solutions. This is due to differences in the emission formation and auto-ignition between the different reaction schemes. Overall, the engine efficiency is increased by 3.5 \% points, and specific CO2 emissions are reduced by 99 g/kWh for ethanol and 142 g/kWh for methanol combustion compared to the base case. This is achieved by advanced spark timing, lean combustion, and reduced C:H ratio of ethanol and methanol in relation to RON95E10.}, language = {en} } @misc{ShresthaSeidelZeuchetal., author = {Shrestha, Krishna Prasad and Seidel, Lars and Zeuch, Thomas and Mor{\´e}ac, Gladys and Dagaut, Philippe and Mauß, Fabian}, title = {On the implications of nitromethane - NOx chemistry interactions for combustion processes}, series = {Fuel}, volume = {289}, journal = {Fuel}, issn = {0016-2361}, doi = {10.1016/j.fuel.2020.119861}, pages = {8}, abstract = {In this work, we report a detailed investigation of the CH3NO2 chemistry effect on fuel-NO interactions for the fuels methane and n-heptane using a recently developed and extensively validated H2/O2/CO/NOx/NH3/CH3NO2 baseline chemistry. In general, the model predictions show good agreement with temperature profiles of major and intermediate species in jet-stirred reactor experiments and they capture the subtle effect of NO addition. For both fuels, the CH3NO2 kinetics retard the system reactivity in the low temperature range by delaying the production of key radicals like OH and HO2. This explains the retarding effect of NO for n-heptane low temperature ignition and the overprediction of reactivity enhancement by NO in earlier studies on methane combustion. For methane, the recently explored roaming mediated dissociation channel of CH3NO2 to CH3O + NO is a major reaction pathway for CH3NO2 consumption. Our analysis suggests that at higher pressure, relevant to engine conditions, the two key intermediate species HONO and CH3NO2 feature strongly increased concentrations during n-heptane combustion and they may be detectable under such conditions in combustion experiments of this fuel-NOx system. The results of this work call for detailed future investigations of the CH3NO2 chemistry effect in the context of exhaust gas recirculation, also with regard to the suppression of engine knock.}, language = {en} } @misc{RichterGuentherMauss, author = {Richter, Jana and G{\"u}nther, Vivien and Mauß, Fabian}, title = {Reaction mechanism development and investigation on the convergence influence in a 1D catalyst model for a γ-alumina stabilized three-way catalyst}, series = {The Proceedings of the International symposium on diagnostics and modeling of combustion in internal combustion engines}, journal = {The Proceedings of the International symposium on diagnostics and modeling of combustion in internal combustion engines}, issn = {2424-2918}, doi = {10.1299/jmsesdm.2022.10.A10-3}, abstract = {Accurate and computational cost-effective modeling tools for the optimization of processes and devices of all kinds are needed in nearly all scientific fields. While experimental optimization entails high expenses in terms of cost and time virtual optimization may be a promising alternative. In this work, the suitability and accuracy of a 1D heterogeneous catalytic model is investigated. First, the influence of cell discretization and residence time on the convergence in a 1D catalyst model are investigated. Second, the catalyst model is investigated and validated with use of a stoichiometric steady state three-way catalyst experiment. With the help of these investigations the reaction mechanism is further developed and new reaction rates for two reactions are presented. The modeling results are compared to a 2D simulation approach in terms of computational time and catalyst conversion behavior. The presented model is capable to capture the experimental results with a drastically reduced computational time in comparison to the 2D simulation presented in literature.}, language = {en} } @misc{ShresthaGiriAdiletal., author = {Shrestha, Krishna Prasad and Giri, Binod Raj and Adil, Mohammad and Seidel, Lars and Zeuch, Thomas and Farooq, Aamir and Mauß, Fabian}, title = {Detailed Chemical Kinetic Study of Acetaldehyde Oxidation and Its Interaction with NOx}, series = {Energy \& fuels}, volume = {35}, journal = {Energy \& fuels}, number = {18}, issn = {1520-5029}, doi = {10.1021/acs.energyfuels.1c01948}, pages = {14963 -- 14983}, abstract = {This work entails a detailed modeling and experimental study for the oxidation kinetics of acetaldehyde (CH3CHO) and its interaction with NOx. The ignition behavior of CH3CHO/O2/Ar has been investigated in a shock tube over the temperature range of 1149 to 1542 K, with equivalence ratios of 0.5 and 1.0 and pressures near 1.2 bar. Absorbance-time profiles of acetaldehyde were recorded using a mid-IR laser during the autoignition measurements. A comprehensive kinetic model has been developed to quantitatively predict the oxidation of acetaldehyde and its interaction with NOx. The kinetic model has been validated using experimental data of this work and available literature data from shock tube, plug flow, and jet-stirred reactors, freely propagating, and burner-stabilized premixed flames. For better accuracy of the kinetic model, the thermochemistry of 14 important species in the acetaldehyde submechanism was calculated using ab initio methods. The heat of formation of these species was computed using atomization and isodesmic reaction schemes. For the first time, this modeling study examines the effect of NO on acetaldehyde oxidation behavior over a wide range of experimental conditions. In most cases, the proposed kinetic model captures the experimental trends remarkably well. Interestingly, the doping of NO in CH3CHO did not perturb the NTC behavior of CH3CHO in contrast to other fuels, such as n-heptane and dimethyl ether. However, for flow reactor conditions at 1 atm, doping with 504 ppm of NO was found to promote the reactivity of acetaldehyde by lowering the onset temperature for CH3CHO oxidation by ∼140 K. The hydroxyl radical is the main cause of this shift, which originates from the NO + HO2 = OH + NO2 reaction. Further evolution of hydroxyl radicals occurs via the "NO-NO2" looping mechanism and expedites the reactivity of the system. This experimental and modeling work sheds new light on acetaldehyde oxidation behavior and its interaction with NOx under combustion-relevant conditions.}, language = {en} } @misc{ShresthaVinHerbinetetal., author = {Shrestha, Krishna Prasad and Vin, Nicolas and Herbinet, Olivier and Seidel, Lars and Battin-Leclerc, Fr{\´e}d{\´e}rique and Zeuch, Thomas and Mauß, Fabian}, title = {Insights into nitromethane combustion from detailed kinetic modeling - Pyrolysis experiments in jet-stirred and flow reactors}, series = {Fuel}, volume = {261}, journal = {Fuel}, issn = {0016-2361}, doi = {https://doi.org/10.1016/j.fuel.2019.116349}, pages = {19}, abstract = {The pyrolysis of nitromethane highly diluted in helium was studied in a plug flow reactor and in a jet-stirred reactor at 1.07 bar and over the temperature range from 500 to 1100 K. Mole fraction profiles of major products and of intermediates were identified with gas chromatography and Fourier transform infrared spectroscopy. Using these experimental data, as well as published ones, we have developed a newly compiled model for the prediction of the pyrolysis and of the oxidation of nitromethane in jet-stirred and flow reactors, freely propagating, and burner-stabilized premixed flames, as well as in shock-tubes. The experimental results from the present work and from the literature are interpreted with the help of the kinetic model derived here. This study mainly focuses on the analysis of speciation in different reactors. Among the nitrogenous species, NO is found to be a major product for pyrolysis and oxidation. The model suggests that for nitromethane pyrolysis and oxidation the thermal dissociation channel to CH3 and NO2 is the main reaction path for the nitromethane degradation followed by the H-atom abstraction channel. The most sensitive reactions for nitromethane pyrolysis in a flow reactor and during pyrolysis and oxidation in a jet-stirred reactor are found to be CH3NO2(+M) ⇋ CH3 + NO2(+M) and CH3 + NO2 ⇋ CH3O + NO. The reaction CH3 + NO2 ⇋ CH3O + NO is found to be the most important reaction for all conditions studied. In a burner-stabilized premixed flame, as the mixture gets richer, the thermal dissociation channel CH3NO2(+M) ⇋ CH3 + NO2(+M) becomes more important as the contribution of the H-atom abstraction channel is decreased. Furthermore, in the burner-stabilized premixed flames, it was found that NO is mainly formed via NO2: NO2 + H ⇋ NO + OH, NO2 + CH3 ⇋ CH3O + NO. The model provided an overall reasonable agreement with the experimental data. However, for pyrolysis conditions, future work is desirable to improve predictions of intermediate species. This work extends the kinetic database and helps to improve the understanding of nitromethane chemistry. The kinetic model presented in this work can serve as a base model for hydrocarbons and oxygenated fuels higher than C2 and nitrogen-containing compounds higher than C1 as well as for pure nitrogen compounds.}, language = {en} } @misc{NetzerPasternakSeideletal., author = {Netzer, Corinna and Pasternak, Michal and Seidel, Lars and Ravet, Fr{\´e}d{\´e}ric and Mauß, Fabian}, title = {Computationally efficient prediction of cycle-to-cycle variations in spark-ignition engines}, series = {International Journal of Engine Research}, volume = {21}, journal = {International Journal of Engine Research}, number = {4}, issn = {2041-3149}, doi = {10.1177/1468087419856493}, pages = {649 -- 663}, abstract = {Cycle-to-cycle variations are important to consider in the development of spark-ignition engines to further increase fuel conversion efficiency. Direct numerical simulation and large eddy simulation can predict the stochastics of flows and therefore cycle-to-cycle variations. However, the computational costs are too high for engineering purposes if detailed chemistry is applied. Detailed chemistry can predict the fuels' tendency to auto-ignite for different octane ratings as well as locally changing thermodynamic and chemical conditions which is a prerequisite for the analysis of knocking combustion. In this work, the joint use of unsteady Reynolds-averaged Navier-Stokes simulations for the analysis of the average engine cycle and the spark-ignition stochastic reactor model for the analysis of cycle-to-cycle variations is proposed. Thanks to the stochastic approach for the modeling of mixing and heat transfer, the spark-ignition stochastic reactor model can mimic the randomness of turbulent flows that is missing in the Reynolds-averaged Navier-Stokes modeling framework. The capability to predict cycle-to-cycle variations by the spark-ignition stochastic reactor model is extended by imposing two probability density functions. The probability density function for the scalar mixing time constant introduces a variation in the turbulent mixing time that is extracted from the unsteady Reynolds-averaged Navier-Stokes simulations and leads to variations in the overall mixing process. The probability density function for the inflammation time accounts for the delay or advancement of the early flame development. The combination of unsteady Reynolds-averaged Navier-Stokes and spark-ignition stochastic reactor model enables one to predict cycle-to-cycle variations using detailed chemistry in a fraction of computational time needed for a single large eddy simulation cycle.}, language = {en} } @misc{NetzerSeidelRavetetal., author = {Netzer, Corinna and Seidel, Lars and Ravet, Fr{\´e}d{\´e}ric and Mauß, Fabian}, title = {Assessment of the validity of RANS knock prediction using the resonance theory}, series = {International Journal of Engine Research}, volume = {21}, journal = {International Journal of Engine Research}, number = {4}, issn = {2041-3149}, doi = {10.1177/1468087419846032}, pages = {610 -- 621}, abstract = {Following the resonance theory by Bradley and co-workers, engine knock is a consequence of an auto-ignition in the developing detonation regime. Their detonation diagram was developed using direct numerical simulations and was applied in the literature to engine knock assessment using large eddy simulations. In this work, it is analyzed if the detonation diagram can be applied for post-processing and evaluation of predicted auto-ignitions in Reynolds-averaged Navier-Stokes simulations even though the Reynolds-averaged Navier-Stokes approach cannot resolve the fine structures resolved in direct numerical simulations and large eddy simulations that lead to the prediction of a developing detonation. For this purpose, an engine operating point at the knock limit spark advance is simulated using Reynolds-averaged Navier-Stokes and large eddy simulations. The combustion is predicted using the G-equation and the well-stirred reactor model in the unburnt gases based on a detailed gasoline surrogate reaction scheme. All the predicted ignition kernels are evaluated using the resonance theory in a post-processing step. According to the different turbulence models, the predicted pressure rise rates and gradients differ. However, the predicted ignition kernel sizes and imposed gas velocities by the auto-ignition event are similar, which suggests that the auto-ignitions predicted by Reynolds-averaged Navier-Stokes simulations can be given a meaningful interpretation within the detonation diagram.}, language = {en} } @misc{ShresthaEckartElbazetal., author = {Shrestha, Krishna Prasad and Eckart, Sven and Elbaz, Ayman M. and Giri, Binod Raj and Fritsche, Chris and Seidel, Lars and Roberts, William L. and Krause, Hartmut and Mauß, Fabian}, title = {A comprehensive kinetic model for dimethyl ether and dimethoxymethane oxidation and NOx interaction utilizing experimental laminar flame speed measurements at elevated pressure and temperature}, series = {Combustion and Flame}, volume = {218}, journal = {Combustion and Flame}, issn = {1556-2921}, doi = {10.1016/j.combustflame.2020.04.016}, pages = {57 -- 74}, abstract = {Laminar flame speeds of dimethyl ether and dimethoxymethane at pressures from 1 to 5 bar and initial temperatures from 298 to 373 K were determined experimentally using a constant volume spherical vessel and a heat flux burner setup. This study is the first to report dimethoxymethane laminar flame speeds at a pressure higher than 1 bar. Using these experimental data along with data available in the literature, a new kinetic model for the prediction of the oxidation behavior of dimethyl ether and dimethoxymethane in freely propagating and burner stabilized premixed flames, in shock tubes, rapid compression machines, flow reactors, and a jet-stirred reactor has been developed. The experimental results from the present work and literature are interpreted with the help of the derived kinetic model. This newly developed reaction mechanism considers the redox chemistry of NOx to accommodate the influence of the oxygen level on the onset of fuel conversion and interconversion of NO and NO2. The current model suggests that an increased O2 level promotes the HO2 production, which in turn leads to the formation of OH radicals, which promotes the combustion of the fuel/air mixture under lean conditions. The increase of OH radical concentrations is mainly via the NO/NO2 interconversion reaction channel, NO+HO2=NO2+OH, NO2+H=NO+OH, CH3OCH3+NO2=CH3OCH2+HONO, followed by the thermal decomposition of HONO. This work extends the kinetic database and helps to improve the understanding of dimethyl ether and dimethoxymethane combustion behavior. The kinetic model presented in this work can serve as a base model for hydrocarbons and oxygenated fuels higher than C2.}, language = {en} } @misc{FrankenMaussSeideletal., author = {Franken, Tim and Mauß, Fabian and Seidel, Lars and Gern, Maike Sophie and Kauf, Malte and Matrisciano, Andrea and Kulzer, Andre Casal}, title = {Gasoline engine performance simulation of water injection and low-pressure exhaust gas recirculation using tabulated chemistry}, series = {International Journal of Engine Research}, volume = {21}, journal = {International Journal of Engine Research}, number = {10}, issn = {2041-3149}, doi = {10.1177/1468087420933124}, pages = {1857 -- 1877}, abstract = {This work presents the assessment of direct water injection in spark-ignition engines using single cylinder experiments and tabulated chemistry-based simulations. In addition, direct water injection is compared with cooled low-pressure exhaust gas recirculation at full load operation. The analysis of the two knock suppressing and exhaust gas cooling methods is performed using the quasi-dimensional stochastic reactor model with a novel dual fuel tabulated chemistry model. To evaluate the characteristics of the autoignition in the end gas, the detonation diagram developed by Bradley and coworkers is applied. The single cylinder experiments with direct water injection outline the decreasing carbon monoxide emissions with increasing water content, while the nitrogen oxide emissions indicate only a minor decrease. The simulation results show that the engine can be operated at l = 1 at full load using water-fuel ratios of up to 60\% or cooled low-pressure exhaust gas recirculation rates of up to 30\%. Both technologies enable the reduction of the knock probability and the decrease in the catalyst inlet temperature to protect the aftertreatment system components. The strongest exhaust temperature reduction is found with cooled low-pressure exhaust gas recirculation. With stoichiometric air-fuel ratio and water injection, the indicated efficiency is improved to 40\% and the carbon monoxide emissions are reduced. The nitrogen oxide concentrations are increased compared to the fuel-rich base operating conditions and the nitrogen oxide emissions decrease with higher water content. With stoichiometric air-fuel ratio and exhaust gas recirculation, the indicated efficiency is improved to 43\% and the carbon monoxide emissions are decreased. Increasing the exhaust gas recirculation rate to 30\% drops the nitrogen oxide emissions below the concentrations of the fuel-rich base operating conditions.}, language = {en} } @misc{FrankenSeidelMatriscianoetal., author = {Franken, Tim and Seidel, Lars and Matrisciano, Andrea and Mauß, Fabian and Kulzer, Andre Casal and Schuerg, Frank}, title = {Analysis of the Water Addition Efficiency on Knock Suppression for Different Octane Ratings}, series = {SAE World Congress}, journal = {SAE World Congress}, issn = {2688-3627}, doi = {10.4271/2020-01-0551}, pages = {5}, abstract = {Water injection can be applied to spark ignited gasoline engines to increase the Knock Limit Spark Advance and improve the thermal efficiency. The Knock Limit Spark Advance potential of 6 °CA to 11 °CA is shown by many research groups for EN228 gasoline fuel using experimental and simulation methods. The influence of water is multi-layered since it reduces the in-cylinder temperature by vaporization and higher heat capacity of the fresh gas, it changes the chemical equilibrium in the end gas and increases the ignition delay and decreases the laminar flame speed. The aim of this work is to extend the analysis of water addition to different octane ratings. The simulation method used for the analysis consists of a detailed reaction scheme for gasoline fuels, the Quasi-Dimensional Stochastic Reactor Model and the Detonation Diagram. The detailed reaction scheme is used to create the dual fuel laminar flame speed and combustion chemistry look-up tables. The Detonation Diagram is used as a novel approach in the Quasi-Dimensional Stochastic Reactor Model to evaluate the auto-ignition characteristic in the end gas and determine if it is a harmless deflagration or developing detonation. First, the Quasi-Dimensional Stochastic Reactor Model is trained for three engine operating points and a RON95 E10 fuel. Its performance is evaluated based on experimental results of a single cylinder research engine. Subsequently, different spark timings and water-fuel ratios are investigated for different Primary Reference Fuels. The results outline that water addition can effectively reduce the strength of auto-ignition in the end gas for different Primary Reference Fuels. Thereby, it can be stated that the reduction of the auto-ignition strength through water addition by 50 - 80 \% water-fuel ratio for high octane number fuels corresponds to the spark timing delay of 6 °CA or an increase of research octane number by 10 points.}, language = {en} } @misc{ShresthaLhuillierBarbosaetal., author = {Shrestha, Krishna Prasad and Lhuillier, Charles and Barbosa, Amanda Alves and Brequigny, Pierre and Contino, Francesco and Mouna{\"i}m-Rousselle, Christine and Seidel, Lars and Mauß, Fabian}, title = {An experimental and modeling study of ammonia with enriched oxygen content and ammonia/hydrogen laminar flame speed at elevated pressure and temperature}, series = {Proceedings of the Combustion Institute}, volume = {2020}, journal = {Proceedings of the Combustion Institute}, issn = {1540-7489}, doi = {10.1016/j.proci.2020.06.197}, pages = {1 -- 12}, abstract = {Laminar flame speeds of ammonia with oxygen-enriched air (oxygen content varying from 21 to 30 vol.\%) and ammonia-hydrogen-air mixtures (fuel hydrogen content varying from 0 to 30 vol.\%) at elevated pressure (1-10 bar) and temperature (298-473 K) were determined experimentally using a constant volume combustion chamber. Moreover, ammonia laminar flame speeds with helium as an inert were measured for the first time. Using these experimental data along with published ones, we have developed a newly compiled kinetic model for the prediction of the oxidation of ammonia and ammonia-hydrogen blends in freely propagating and burner stabilized premixed flames, as well as in shock tubes, rapid compression machines and a jet-stirred reactor. The reaction mechanism also considers the formation of nitrogen oxides, as well as the reduction of nitrogen oxides depending on the conditions of the surrounding gas phase. The experimental results from the present work and the literature are interpreted with the help of the kinetic model derived here. The experiments show that increasing the initial temperature, fuel hydrogen content, or oxidizer oxygen content causes the laminar flame speed to increase, while it decreases when increasing the initial pressure. The proposed kinetic model predicts the same trends than experiments and a good agreement is found with measurements for a wide range of conditions. The model suggests that under rich conditions the N2H2 formation path is favored compared to stoichiometric condition. The most important reactions under rich conditions are: NH2+NH=N2H2+H, NH2+NH2=N2H2+H2, N2H2+H=NNH+H2 and N2H2+M=NNH+H+M. These reactions were also found to be among the most sensitive reactions for predicting the laminar flame speed for all the cases investigated.}, language = {en} } @misc{IssayevGiriElbazetal., author = {Issayev, Gani and Giri, Binod Raj and Elbaz, Ayman M. and Shrestha, Krishna Prasad and Mauß, Fabian and Roberts, William L. and Farooq, Aamir}, title = {Combustion behavior of ammonia blended with diethyl ether}, series = {Proceedings of the Combustion Institute}, volume = {38 (2021)}, journal = {Proceedings of the Combustion Institute}, number = {1}, issn = {1540-7489}, doi = {10.1016/j.proci.2020.06.337}, pages = {499 -- 506}, abstract = {Ammonia (NH3) is recognized as a carbon-free hydrogen-carrier fuel with a high content of hydrogen atoms per unit volume. Recently, ammonia has received increasing attention as a promising alternative fuel for internal combustion engine and gas turbine applications. However, the viability of ammonia fueling future combustion devices has several barriers to overcome. To overcome the challenge of its low reactivity, it is proposed to blend it with a high-reactivity fuel. In this work, we have investigated the combustion characteristics of ammonia/diethyl ether (NH3/DEE) blends using a rapid compression machine (RCM) and a constant volume spherical reactor (CVSR). Ignition delay times (IDTs) of NH3/DEE blends were measured using the RCM over a temperature range of 620 to 942 K, pressures near 20 and 40 bar, equivalence ratios (Φ) of 1 and 0.5, and a range of mole fractions of DEE, χDEE, from 0.05 to 0.2 (DEE/NH3 = 5 - 20\%). Laminar burning velocities of NH3/DEE premixed flames were measured using the CVSR at 298 K, 1 bar, Φ of 0.9 to 1.3, and χDEE from 0.1 to 0.4. Our results indicate that DEE promotes the reactivity of fuel blends resulting in significant shortening of the ignition delay times of ammonia under RCM conditions. IDTs expectedly exhibited strong dependence on pressure and equivalence ratio for a given blend. Laminar burning velocity was found to increase with increasing fraction of DEE. The burnt gas Markstein length increased with equivalence ratio for χDEE = 0.1 as seen in NH3-air flames, while the opposite evolution of Markstein length was observed with Φ for 0.1 < χDEE ≤ 0.4, as observed in isooctane-air flames. A detailed chemical kinetics model was assembled to analyze and understand the combustion characteristics of NH3/DEE blends.}, language = {en} } @misc{ElbazGiriIssayevetal., author = {Elbaz, Ayman M. and Giri, Binod Raj and Issayev, Gani and Shrestha, Krishna Prasad and Mauß, Fabian and Farooq, Aamir and Roberts, William L.}, title = {Experimental and Kinetic Modeling Study of Laminar Flame Speed of Dimethoxymethane and Ammonia Blends}, series = {Energy \& Fuels}, volume = {34}, journal = {Energy \& Fuels}, number = {11}, issn = {1520-5029}, doi = {10.1021/acs.energyfuels.0c02269}, pages = {14727 -- 14740}, abstract = {Ammonia (NH3) is considered a promising carbon-neutral fuel, with a high hydrogen content, that can diversify the global energy system. Blending ammonia with a highly reactive fuel is one possible strategy to enhance its combustion characteristics. Here, an investigation of blends of NH3 and dimethoxymethane (DMM), a biofuel with high fuel-born oxygen content and no carbon-carbon bonds, is reported. Unstretched laminar burning velocity (SL) and Markstein length of different NH3/DMM blends were experimentally determined using spherically propagating premixed flames. The DMM mole fraction was varied from 0.2 to 0.6 while measuring SL at 298 K, 0.1 MPa, and equivalence ratios (Φ) over the range of 0.8-1.3. The addition of DMM was found to immensely enhance the combustion characteristics of ammonia. DMM 20\% (by mole fraction) in the NH3/DMM blend increased SL by more than a factor of 3 over neat ammonia; such enhancement was found to be comparable to 60\% CH4 in NH3 (Φ = 0.9-1.1) blends. Increasing Φ was found to significantly decrease the burned gas Markstein length for lean cases, whereas a negligible effect was observed for rich mixtures. A composite chemical kinetic model of DMM/NH3, aimed at interpreting the high-temperature combustion chemistry, was able to reliably predict SL for neat NH3 and DMM flames. Also, the predictive capability of the kinetic model to describe SL for DMM/NH3 blends is reasonably good. Sensitivity analysis and reaction path analysis indicated that the NH3/DMM blends could be understood as dual oxidation processes of the individual fuels that are competing for the same radical pool.}, language = {en} } @misc{NetzerLiSeideletal., author = {Netzer, Corinna and Li, Tian and Seidel, Lars and Mauß, Fabian and L{\o}v{\aa}s, Terese}, title = {Stochastic Reactor-Based Fuel Bed Model for Grate Furnaces}, series = {Energy \& Fuels}, volume = {34}, journal = {Energy \& Fuels}, number = {12}, issn = {1520-5029}, doi = {10.1021/acs.energyfuels.0c02868}, pages = {16599 -- 16612}, abstract = {Biomass devolatilization and incineration in grate-fired plants are characterized by heterogeneous fuel mixtures, often incompletely mixed, dynamical processes in the fuel bed and on the particle scale, as well as heterogeneous and homogeneous chemistry. This makes modeling using detailed kinetics favorable but computationally expensive. Therefore, a computationally efficient model based on zero-dimensional stochastic reactors and reduced chemistry schemes, consisting of 83 gas-phase species and 18 species for surface reactions, is developed. Each reactor is enabled to account for the three phases: the solid phase, pore gas surrounding the solid, and the bulk gas. The stochastic reactors are connected to build a reactor network that represents the fuel bed in grate-fired furnaces. The use of stochastic reactors allows us to account for incompletely mixed fuel feeds, distributions of local temperature and local equivalence ratio within each reactor and the fuel bed. This allows us to predict the released gases and emission precursors more accurately than if a homogeneous reactor network approach was employed. The model approach is demonstrated by predicting pyrolysis conditions and two fuel beds of grate-fired plants from the literature. The developed approach can predict global operating parameters, such as the fuel bed length, species release to the freeboard, and species distributions within the fuel bed to a high degree of accuracy when compared to experiments.}, language = {en} } @misc{FrankenDugganTaoetal., author = {Franken, Tim and Duggan, Alexander and Tao, Feng and Matrisciano, Andrea and Lehtiniemi, Harry and Borg, Anders and Mauß, Fabian}, title = {Multi-Objective Optimization of Fuel Consumption and NOx Emissions of a heavy-duty Diesel engine using a Stochastic Reactor Model}, series = {SAE technical paper}, journal = {SAE technical paper}, number = {2019-01-1173}, issn = {0096-5170}, abstract = {Highly fuel-efficient Diesel engines, combined with effective exhaust aftertreatment systems, enable an economic and low-emission operation of heavy-duty vehicles. The challenge of its development arises from the present engine complexity, which is expected to increase even more in the future. The approved method of test bench measurements is stretched to its limits, because of the high demand for large parameter variations. The introduction of a physics-based quasi-dimensional stochastic reactor model combined with tabulated chemistry enables the simulation-supported development of these Diesel engines. The stochastic reactor model mimics mixture and temperature inhomogeneities induced by turbulence, direct injection and heat transfer. Thus, it is possible to improve the prediction of NOx emissions compared to common mean-value models. To reduce the number of designs to be evaluated during …}, language = {en} } @misc{NetzerSeidelRavetetal., author = {Netzer, Corinna and Seidel, Lars and Ravet, Fr{\´e}d{\´e}ric and Mauß, Fabian}, title = {Impact of the surrogate formulation on 3D CFD engine knock prediction using detailed chemistry}, series = {Fuel}, volume = {Volume 254}, journal = {Fuel}, issn = {1873-7153}, doi = {10.1016/j.fuel.2019.115678}, pages = {13}, abstract = {For engine knock prediction, surrogate fuels are often composed of iso-octane and n-heptane since they are the components of the Primary Reference Fuel (PRF). By definition, a PRF has no octane sensitivity (S = RON-MON). However, for a commercial gasoline fuel holds RON > MON and therefor S > 0. More complex surrogates are Toluene Reference Fuels (TRF) and Ethanol containing Toluene Reference Fuels (ETRF). In this work, the impact of the surrogate formulation on the prediction of flame propagation and auto-ignition in the unburnt gases are investigated. The surrogates are composed such that the Research Octane Number is the same. The auto-ignition events ahead of the flame front are predicted using 3D CFD and a combustion model based on the ETRF mechanism by Seidel (2017). The strength of the auto-ignition is determined using the detonation diagram by Bradley and co-workers (2002, 2003). Applying the different surrogates, ignition kernels of different size and reactivity are predicted. The results indicate a dependency on the local temperature history and the low temperature chemistry of the fuel species. The comparison of homogenous constant volume reactor and transient simulations show that the analysis of ignition delay time and octane rating solely from homogenous simulations is not sufficient if the knock tendency of a surrogate in engine simulations needs to be characterized.}, language = {en} } @misc{ShresthaSeidelZeuchetal., author = {Shrestha, Krishna Prasad and Seidel, Lars and Zeuch, Thomas and Mauß, Fabian}, title = {Kinetic Modeling of NOx Formation and Consumption during Methanol and Ethanol Oxidation}, series = {Combustion Science and Technology}, volume = {191}, journal = {Combustion Science and Technology}, number = {9}, issn = {1563-521X}, doi = {10.1080/00102202.2019.1606804}, pages = {1628 -- 1660}, language = {en} } @misc{FrankenNetzerMaussetal., author = {Franken, Tim and Netzer, Corinna and Mauß, Fabian and Pasternak, Michal and Seidel, Lars and Borg, Anders and Lehtiniemi, Harry and Matrisciano, Andrea and Kulzer, Andr{\´e} Casal}, title = {Multi-objective optimization of water injection in spark-ignition engines using the stochastic reactor model with tabulated chemistry}, series = {International Journal of Engine Research}, volume = {20}, journal = {International Journal of Engine Research}, number = {10}, issn = {2041-3149}, doi = {10.1177/1468087419857602}, pages = {1089 -- 1100}, abstract = {Water injection is investigated for turbocharged spark-ignition engines to reduce knock probability and enable higher engine efficiency. The novel approach of this work is the development of a simulation-based optimization process combining the advantages of detailed chemistry, the stochastic reactor model and genetic optimization to assess water injection. The fast running quasi-dimensional stochastic reactor model with tabulated chemistry accounts for water effects on laminar flame speed and combustion chemistry. The stochastic reactor model is coupled with the Non-dominated Sorting Genetic Algorithm to find an optimum set of operating conditions for high engine efficiency. Subsequently, the feasibility of the simulation-based optimization process is tested for a three-dimensional computational fluid dynamic numerical test case. The newly proposed optimization method predicts a trade-off between fuel efficiency and low knock probability, which highlights the present target conflict for spark-ignition engine development. Overall, the optimization shows that water injection is beneficial to decrease fuel consumption and knock probability at the same time. The application of the fast running quasi-dimensional stochastic reactor model allows to run large optimization problems with low computational costs. The incorporation with the Non-dominated Sorting Genetic Algorithm shows a well performing multi-objective optimization and an optimized set of engine operating parameters with water injection and high compression ratio is found.}, language = {en} } @misc{LeonRuweMoshammeretal., author = {Le{\´o}n, Larisa and Ruwe, Lena and Moshammer, Kai and Seidel, Lars and Shrestha, Krishna Prasad and Wang, Xiaoxiao and Mauß, Fabian and Kohse-H{\"o}inghaus, Katharina and Hansen, Nils}, title = {Chemical insights into the larger sooting tendency of 2-methyl-2-butene compared to n-pentane}, series = {Combustion and Flame}, volume = {208}, journal = {Combustion and Flame}, issn = {0010-2180}, doi = {10.1016/j.combustflame.2019.06.029}, pages = {182 -- 197}, abstract = {A comprehensive, chemically detailed mechanism for the combustion of 2-methyl-2-butene and n-pentane is presented to provide insights into the different sooting tendencies of these two structurally different C5 hydrocarbons. A hierarchically assembled mechanism has been developed to specifically target speciation data from low-pressure premixed flames of 2-methyl-2-butene [Ruwe et al., Combust. Flame, 175, 34-46, 2017] and newly measured mole fraction data for a fuel-rich (ɸ=1.8) n-pentane flame, in which species profiles up to phenol were quantified. The partially isomer-resolved chemical composition of this flame was determined using flame-sampling molecular-beam mass spectrometry with single-photon ionization by tunable, synchrotron-generated vacuum-ultraviolet radiation. The presented model, which includes a newly determined, consistent set of the thermochemistry data for the C5 species, presents overall satisfactory capabilities to predict the mole fraction profiles of common combustion intermediates. The analysis of the model predictions revealed the fuel-structure dependencies (i.e. saturated vs. unsaturated and linear vs. branched) of the formation of small aromatic species that are considered as soot precursors. The propensity of the 2-methyl-2-butene flame to form larger concentrations of aromatic species was traced back to the readily available formation routes of several small precursor molecules and the efficient formation of "first aromatic rings" beyond benzene.}, language = {en} } @misc{ShresthaSeidelZeuchetal., author = {Shrestha, Krishna Prasad and Seidel, Lars and Zeuch, Thomas and Mauß, Fabian}, title = {Modeling for Nitromethane oxidation}, series = {1st International Conference on Smart Energy Carriers Napoli, 2019}, journal = {1st International Conference on Smart Energy Carriers Napoli, 2019}, abstract = {The diminishing availability of conventional fuels and stricter regulations on pollution control and CO2 emission targets have led scientist and engineers to look for alternative fuels. Recently nitromethane has slowly gained interest as alternative fuel over conventional fuel for internal combustion engines. In the past, it was mostly used as rocket propellant or as an explosives [1,2]. Nitromethane is an energetic compound with a wide variety of applications, including its use as a monopropellant, a liquid explosive, a solvent for chemical processing and analysis, and a highperformance fuel additive for internal combustion engines and pulsed detonation engines [3]. The chemical formula of nitromethane is CH3NO2. As the name suggests, the molecule is essentially methane with one of the four hydrogens replaced by a nitro group. In essence, it is the simplest of possible energetic CHON molecules that contain nitro groups, which is why it is often used in reaction studies as a prototype for more complex energetic materials. There is no reliable kinetic model for nitromethane combustion, which is validated over a wide range of experimental conditions. There are a few published studies [4-8] both numerically and experimentally focusing often on a single reactor at very specific conditions. The aim of the present work is to extend our recently published mechanism [9] for syngas, methane and ammonia oxidation to include CH3NO2 as fuel and validate against the available experimental data from the literature. The development and compilation strategy for our mechanism is described in our recent work [9] and this study is conducted in a similar manner. Rates are taken mainly from [7,10-16]. This makes the kinetic model more robust and reliable for combustion modelling.}, language = {en} } @misc{ShresthaSeidelZeuchetal., author = {Shrestha, Krishna Prasad and Seidel, Lars and Zeuch, Thomas and Mauß, Fabian}, title = {Modeling of NOx Formation and Consumption during Oxidation of Small Alcohols}, series = {9th European Combustion Meeting, Proceedings of the European Combustion Meeting}, journal = {9th European Combustion Meeting, Proceedings of the European Combustion Meeting}, pages = {6}, abstract = {This work presents a newly developed kinetic mechanism extending our recent work (Shrestha et al. [1]) for the oxidation of methanol and ethanol and their fuel interaction with NO x chemistry in jet-stirred reactors, flow reactors, and burner-stabilized premixed flames. The work mainly focuses on fuel interaction with nitrogen chemistry and NO formation in laminar premixed flames. It is found that for methanol oxidation in jet-stirred reactor doping of the fuel blends with NO increase the reactivity of the system by increasing the net production of OH radicals. The increased amount of OH is formed via NO/NO 2 interconversion reaction channels NO+HO 2 ⇋NO 2 +OH, NO 2 +H⇋NO+OH, NO 2 +HO 2 ⇋HONO+O 2, followed by the thermal decomposition of HONO producing NO and OH. In burner-stabilized premixed flames studied here for methanol/air and ethanol/air, NO is mainly formed via the NCN route (CH+N 2 ⇋NCN+H) and minor contribution comes from the NNH route (NNN⇋N 2 +H).}, language = {en} } @misc{MedinaMendezSchmidtMaussetal., author = {Medina M{\´e}ndez, Juan Ali and Schmidt, Heiko and Mauß, Fabian and Jozefik, Zoltan}, title = {Constant volume n-Heptane autoignition using One-Dimensional Turbulence}, series = {Combustion and Flame}, volume = {190}, journal = {Combustion and Flame}, issn = {0010-2180}, doi = {10.1016/j.combustflame.2017.12.015}, pages = {388 -- 401}, abstract = {Abstract Constant volume premixed lean n-Heptane/air autoignition at high pressure is investigated using the One-Dimensional Turbulence (ODT) model. The configuration consists of a 1D fixed volume domain with a prescribed velocity spectrum and temperature fluctuations superimposed on an initial uniformly elevated scalar field. The sensitivity of the heat release rate and pressure evolution to the initial temperature distribution is studied by imposing different initial temperature fields while holding the mean, RMS and integral length scale of the field constant. Three detailed chemical mechanisms are employed for the prediction of autoignition and heat release rate. To mitigate the high computational cost associated with the calculation of the chemical source terms in the stiff complex mechanisms, an approach based on the Strang-Splitting method is presented. Finally, a …}, language = {en} } @misc{AslanjanKlauerGuentheretal., author = {Aslanjan, Jana and Klauer, Christian and G{\"u}nther, Vivien and Mauß, Fabian}, title = {Development of a Physical Parameter Optimizer for 1D Catalyst Modeling on the Example of a Transient Three-Way Catalyst Experiment, 37th International Symposium on Combustion 2018, Dublin}, pages = {1}, abstract = {The importance of catalytic after-treatment for automotive emissions is not neglectable concerning current environmental protection discussions. A reasonable and time efficient catalyst model can help to reduce the necessity of time consuming experimental investigations on physical parameters for catalytic converter construction. It can further support the preparation of necessary experimental setups to analyze physical and chemical phenomena in catalysts. Physical parameter and/or chemical kinetic optimizers can be an advanced tool to support computational models in terms of adjustment to an experiment. In this work a physical parameter optimizer is developed and validated against a transient three-way catalyst experiment. The modeling results are compared to the measured data in terms of temperature and emission conversion behavior and show a good agreement.}, language = {en} } @misc{NetzerFrankenLehtiniemietal., author = {Netzer, Corinna and Franken, Tim and Lehtiniemi, Harry and Mauß, Fabian and Seidel, Lars}, title = {Numerical Analysis of the Impact of Water Injection on Combustion and Thermodynamics in a Gasoline Engine using Detailed Chemistry}, series = {SAE technical papers}, journal = {SAE technical papers}, number = {2018-01-0200}, issn = {0148-7191}, doi = {10.4271/2018-01-0200}, pages = {14}, language = {en} } @misc{PasternakMaussKlaueretal., author = {Pasternak, Michal and Mauß, Fabian and Klauer, Christian and Matrisciano, Andrea}, title = {Diesel engine performance mapping using a parametrized mixing time model}, series = {International Journal of Engine Research}, volume = {19}, journal = {International Journal of Engine Research}, number = {2}, issn = {2041-3149}, doi = {10.1177/1468087417718115}, pages = {202 -- 213}, language = {en} } @misc{FrankenDugganFengetal., author = {Franken, Tim and Duggan, Alexander and Feng, Tao and Borg, Anders and Lehtiniemi, Harry and Matrisciano, Andrea and Mauß, Fabian}, title = {Multi-Objective Optimization of Fuel Consumption and NOx Emissions using a Stochastic Reactor Model, THIESEL 2018 Conference on Thermo- and Fluid Dynamic Processes in Direct Injection Engines}, language = {en} } @misc{FrankenNetzerPasternaketal., author = {Franken, Tim and Netzer, Corinna and Pasternak, Michal and Mauß, Fabian and Seidel, Lars and Matrisciano, Andrea and Borg, Anders and Lehtiniemi, Harry and Kulzer, Andr{\´e} Casal}, title = {Simulation of Spark-Ignited Engines with Water Injection using the Stochastic Reactor Model, 37th International Symposium on Combustion}, language = {en} } @misc{FrankenNetzerMauss, author = {Franken, Tim and Netzer, Corinna and Mauß, Fabian}, title = {Water Injection in Spark-Ignition Engines, FVV Autumn Conference 2018}, language = {en} } @misc{AgbroTomlinZhangetal., author = {Agbro, Edirin and Tomlin, Alison S. and Zhang, Wankang and Burluka, Alexey and Mauß, Fabian and Alfazazi, Adamu and Sarathy, S. Mani}, title = {Chemical Kinetic Modeling Study on the Influence of n-Butanol Blending on the Combustion, Autoignition, and Knock Properties of Gasoline and Its Surrogate in a Spark-Ignition Engine}, series = {American Chemical Society}, volume = {32}, journal = {American Chemical Society}, number = {10}, issn = {1520-5029}, doi = {10.1021/acs.energyfuels.8b00962}, pages = {10065 -- 10077}, abstract = {The ability of a mechanism describing the oxidation kinetics of toluene reference fuel (TRF)/n-butanol mixtures to predict the impact of n-butanol blending at 20\% by volume on the autoignition and knock properties of gasoline has been investigated under conditions of a strongly supercharged spark-ignition (SI) engine. Simulations were performed using the LOGEengine code for stoichiometric fuel/air mixtures at intake temperature and pressure conditions of 320 K and 1.6 bar, respectively, for a range of spark timings. At the later spark timing of 6° crank angle (CA) before top dead center (BTDC), the predicted knock onsets for a gasoline surrogate (TRF) and the TRF/n-butanol blend are higher compared to the measurements, which is consistent with an earlier study of ignition delay times predicted in a rapid compression machine (RCM; Agbro, E.; Tomlin, A. S.; Lawes, M.; Park, S.; Sarathy, S. M. The influence of n …}, language = {en} } @misc{ShresthaSeidelZeuchetal., author = {Shrestha, Krishna Prasad and Seidel, Lars and Zeuch, Thomas and Mauß, Fabian}, title = {Detailed Kinetic Mechanism for the Oxidation of Ammonia Including the Formation and Reduction of Nitrogen Oxides}, series = {Energy \& Fuels}, volume = {32}, journal = {Energy \& Fuels}, number = {10}, issn = {1520-5029}, doi = {10.1021/acs.energyfuels.8b01056}, pages = {10202 -- 10217}, abstract = {This work introduces a newly developed reaction mechanism for the oxidation of ammonia in freely propagating and burner-stabilized premixed flames as well as shock-tube, jet-stirred reactor, and plug-flow reactor experiments. The paper mainly focuses on pure ammonia and ammonia-hydrogen fuel blends. The reaction mechanism also considers the formation of nitrogen oxides as well as the reduction of nitrogen oxides depending upon the conditions of the surrounding gas phase. Doping of the fuel blend with NO2 can result in acceleration of H2 autoignition via the reaction NO2 + HO2 ⇋ HONO + O2, followed by the thermal decomposition of HONO, or deceleration of H2 oxidation via NO2 + OH ⇋ NO + HO2. The concentration of HO2 is decisive for the active reaction pathway. The formation of NO in burner-stabilized premixed flames is shown to demonstrate the capability of the mechanism to be integrated …}, language = {en} } @misc{AslanjanKlauerGuentheretal., author = {Aslanjan, Jana and Klauer, Christian and G{\"u}nther, Vivien and Mauß, Fabian}, title = {Simulation of a three-way-catalyst using a transient multi-channel model}, pages = {S. 103}, abstract = {The importance to reduce automotive exhaust gas emissions is constantly increasing. Not only the country-specific laws are getting more stringent also the global increase of automobiles is requiring a responsible handling of the issue. The three-way-catalytic converter (TWC) is one of the most common catalysts for the engine exhaust gas after treatment. The reduction of CO, NO and unburned hydrocarbons is fulfilled via oxidation of carbon monoxide and hydrocarbons, and reduction of nitrogen oxides. These conversion effects were simulated in previous works using single channel approaches [e.g. Fr{\"o}jd/Mauss, SAE International 2011-01-1306] and detailed kinetic models [e.g Chatterjee et al., Faraday Discussions 119 (2001) 371-384 and Koop et al., Appl. Catal.B: Environmental 91 (2009), 47-58]. In this work multiple representative catalyst channels are used to take heat variations in between the catalyst into account. Each channel is split into a user given number of cells and each cell is treated like a perfectly stirred reactor (PSR). The simulation is validated against an experimental four-stroke engine setup with emission outputs fed into a TWC. Next to the emissions the transient temperature increase is simulated in order to model the catalyst light off temperature. The heat transfer is modelled by wall heat losses to provide a proper heat dissipation out of the catalyst. The simulation results show a good agreement to the experimental data with low computational cost.}, language = {en} } @misc{NetzerSeidelPasternaketal., author = {Netzer, Corinna and Seidel, Lars and Pasternak, Michal and Lehtiniemi, Harry and Perlman, Cathleen and Ravet, Fr{\´e}d{\´e}ric and Mauß, Fabian}, title = {Three-dimensional computational fluid dynamics engine knock prediction and evaluation based on detailed chemistry and detonation theory}, series = {International Journal of Engine Research}, volume = {19}, journal = {International Journal of Engine Research}, number = {1}, issn = {1468-0874}, doi = {10.1177/1468087417740271}, pages = {33 -- 44}, abstract = {Engine knock is an important phenomenon that needs consideration in the development of gasoline-fueled engines. In our days, this development is supported using numerical simulation tools to further understand and predict in-cylinder processes. In this work, a model tool chain which uses a detailed chemical reaction scheme is proposed to predict the auto-ignition behavior of fuels with different octane ratings and to evaluate the transition from harmless auto-ignitive deflagration to knocking combustion. In our method, the auto-ignition characteristics and the emissions are calculated using a gasoline surrogate reaction scheme containing pathways for oxidation of ethanol, toluene, n-heptane, iso-octane and their mixtures. The combustion is predicted using a combination of the G-equation based flame propagation model utilizing tabulated laminar flame speeds and well-stirred reactors in the burned and …}, language = {en} } @misc{WernerNetzerLehtiniemietal., author = {Werner, Adina and Netzer, Corinna and Lehtiniemi, Harry and Borg, Anders and Matrisciano, Andrea and Seidel, Lars and Mauß, Fabian}, title = {A Computationally Efficient Combustion Progress Variable (CPV) Approach for Engine Applications}, doi = {10.13140/RG.2.2.15334.27209}, language = {en} } @misc{WernerMatriscianoNetzeretal., author = {Werner, Adina and Matrisciano, Andrea and Netzer, Corinna and Lehtiniemi, Harry and Borg, Anders and Seidel, Lars and Mauß, Fabian}, title = {Further Application of the Fast Tabulated CPV Approach}, doi = {10.13140/RG.2.2.18689.71529}, language = {en} } @misc{HoyermannMaussOlzmannetal., author = {Hoyermann, Karlheinz and Mauß, Fabian and Olzmann, Matthias and Welz, Oliver and Zeuch, Thomas}, title = {Exploring the chemical kinetics of partially oxidized intermediates by combining experiments, theory, and kinetic modeling}, series = {Physical Chemistry Chemical Physics}, volume = {19}, journal = {Physical Chemistry Chemical Physics}, number = {28}, issn = {1463-9076}, doi = {10.1039/C7CP02759A}, pages = {18128 -- 18146}, abstract = {Partially oxidized intermediates play a central role in combustion and atmospheric chemistry. In this perspective, we focus on the chemical kinetics of alkoxy radicals, peroxy radicals, and Criegee intermediates, which are key species in both combustion and atmospheric environments. These reactive intermediates feature a broad spectrum of chemical diversity. Their reactivity is central to our understanding of how volatile organic compounds are degraded in the atmosphere and converted into secondary organic aerosol. Moreover, they sensitively determine ignition timing in internal combustion engines. The intention of this perspective article is to provide the reader with information about the general mechanisms of reactions initiated by addition of atomic and molecular oxygen to alkyl radicals and ozone to alkenes. We will focus on critical branching points in the …}, language = {en} } @misc{WeberLiLovasetal., author = {Weber, Kathrin and Li, T. and L{\o}v{\aa}s, Terese and Perlman, Cathleen and Seidel, Lars and Mauß, Fabian}, title = {Stochastic reactor modeling of biomass pyrolysis and gasification}, series = {Journal of analytical and applied pyrolysis}, volume = {124}, journal = {Journal of analytical and applied pyrolysis}, issn = {0165-2370}, doi = {10.1016/j.jaap.2017.01.003}, pages = {592 -- 601}, abstract = {Abstract In this paper, a partially stirred stochastic reactor model is presented as an alternative for the modeling of biomass pyrolysis and gasification. Instead of solving transport equations in all spatial dimensions as in CFD simulations, the description of state variables and mixing processes is based on a probability density function, making this approach computationally efficient. The virtual stochastic particles, an ensemble of flow elements consisting of porous solid biomass particles and surrounding gas, mimic the turbulent exchange of heat and mass in practical systems without the computationally expensive resolution of spatial dimensions. Each stochastic particle includes solid phase, pore gas and bulk gas interaction. The reactor model is coupled with a chemical mechanism for both surface and gas phase reactions. A Monte Carlo algorithm with operator splitting …}, language = {en} } @misc{SeidelNetzerHilbigetal., author = {Seidel, Lars and Netzer, Corinna and Hilbig, Martin and Mauß, Fabian and Klauer, Christian and Pasternak, Michal and Matrisciano, Andrea}, title = {Systematic reduction of detailed chemical reaction mechanisms for engine applications}, series = {Journal of Engineering for Gas Turbines and Power}, volume = {139}, journal = {Journal of Engineering for Gas Turbines and Power}, number = {9}, issn = {1528-8919}, doi = {10.1115/1.4036093}, pages = {091701-1 -- 091701-9}, abstract = {In this work, we apply a sequence of concepts for mechanism reduction on one reaction mechanism including novel quality control. We introduce a moment-based accuracy rating method for species profiles. The concept is used for a necessity-based mechanism reduction utilizing 0D reactors. Thereafter a stochastic reactor model for internal combustion engines is applied to control the quality of the reduced reaction mechanism during the expansion phase of the engine. This phase is sensitive on engine out emissions, and is often not considered in mechanism reduction work. The proposed process allows to compile highly reduced reaction schemes for computational fluid dynamics application for internal combustion engine simulations. It is demonstrated that the resulting reduced mechanisms predict combustion and emission formation in engines with accuracies comparable to the original detailed scheme.}, language = {en} } @misc{NagyMatriscianoLehtiniemietal., author = {Nagy, Imre Gergely and Matrisciano, Andrea and Lehtiniemi, Harry and Mauß, Fabian and Schmid, Andreas}, title = {Influence of nozzle eccentricity on spray structures in marine diesel sprays}, series = {SAE technical papers}, journal = {SAE technical papers}, number = {2017-24-0031}, issn = {0148-7191}, pages = {13}, abstract = {Abstract: Large two-stroke marine Diesel engines have special injector geometries, which differ substantially from the configurations used in most other Diesel engine applications. One of the major differences is that injector orifices are distributed in a highly non-symmetric fashion affecting the spray characteristics. Earlier investigations demonstrated the dependency of the spray morphology on the location of the spray orifice and therefore on the resulting flow conditions at the nozzle tip. Thus, spray structure is directly influenced by the flow formation within the orifice. Following recent Large Eddy Simulation resolved spray primary breakup studies, the present paper focuses on spray secondary breakup odelling of asymmetric spray structures in Euler-Lagrangian framework based on previously obtained droplet distributions of primary breakup. Firstly, the derived droplet distributions were …}, language = {en} } @misc{NetzerSeidelPasternaketal., author = {Netzer, Corinna and Seidel, Lars and Pasternak, Michal and Klauer, Christian and Perlman, Cathleen and Ravet, Fr{\´e}d{\´e}ric and Mauß, Fabian}, title = {Engine Knock Prediction and Evaluation Based on Detonation Theory Using a Quasi-Dimensional Stochastic Reactor Mode}, series = {SAE technical paper}, journal = {SAE technical paper}, number = {2017-01-0538}, issn = {0096-5170}, doi = {10.4271/2017-01-0538}, pages = {11 Seiten}, language = {en} } @misc{MatriscianoFrankenPerlmanetal., author = {Matrisciano, Andrea and Franken, Tim and Perlman, Cathleen and Borg, Anders and Lehtiniemi, Harry and Mauß, Fabian}, title = {Development of a Computationally Efficient Progress Variable Approach for a Direct Injection Stochastic Reactor Model}, series = {SAE technical papers}, journal = {SAE technical papers}, number = {2017-01-0512}, issn = {0148-7191}, doi = {10.4271/2017-01-0512}, pages = {18 Seiten}, language = {en} } @misc{AslanjanKlauerPerlmanetal., author = {Aslanjan, Jana and Klauer, Christian and Perlman, Cathleen and G{\"u}nther, Vivien and Mauß, Fabian}, title = {Simulation of a Three-Way Catalyst Using Transient Single and Multi-Channel Models}, series = {SAE technical paper}, journal = {SAE technical paper}, number = {2017-01-0966}, issn = {0148-7191}, doi = {10.4271/2017-01-0966}, pages = {11 Seiten}, language = {en} } @inproceedings{NetzerSeidelPasternaketal., author = {Netzer, Corinna and Seidel, Lars and Pasternak, Michal and Mauß, Fabian and Lehtiniemi, Harry and Perlman, Cathleen and Ravet, Fr{\´e}d{\´e}ric}, title = {3D CFD Engine Knock Predication and Evaluation Based on Detailed Chemistry and Detonation Theory}, series = {Motorische Verbrennung : aktuelle Probleme und moderne L{\"o}sungsans{\"a}tze, XIII. Tagung im Haus der Technik Ludwigsburg, 16.-17. M{\"a}rz 2017}, booktitle = {Motorische Verbrennung : aktuelle Probleme und moderne L{\"o}sungsans{\"a}tze, XIII. Tagung im Haus der Technik Ludwigsburg, 16.-17. M{\"a}rz 2017}, editor = {Leipertz, Alfred and Fr{\"o}ba, Andreas Paul}, publisher = {ESYTEC Energie- und Systemtechnik GmbH}, address = {Erlangen}, isbn = {978-3-945806-08-1}, language = {en} } @inproceedings{NetzerSeidelPasternaketal., author = {Netzer, Corinna and Seidel, Lars and Pasternak, Michal and Klauer, Christian and Perlman, Cathleen and Ravet, Fr{\´e}d{\´e}ric and Mauß, Fabian}, title = {Impact of Gasoline Octane Rating on Engine Knock using Detailed Chemistry and a Quasi-dimensional Stochastic Reaktior Model}, series = {Digital Proceedings of the 8th European Combustion Meeting (ECM 2017), Dubrovnik, Croatia}, booktitle = {Digital Proceedings of the 8th European Combustion Meeting (ECM 2017), Dubrovnik, Croatia}, pages = {493 -- 498}, language = {en} } @misc{FrankenSommerhoffWillemsetal., author = {Franken, Tim and Sommerhoff, Arnd and Willems, Werner and Matrisciano, Andrea and Lehtiniemi, Harry and Borg, Anders and Netzer, Corinna and Mauß, Fabian}, title = {Advanced Predictive Diesel Combustion Simulation Using Turbulence Model and Stochastic Reactor Model}, series = {SAE technical paper}, journal = {SAE technical paper}, issn = {0148-7191}, doi = {10.4271/2017-01-0516}, language = {en} } @inproceedings{NetzerSeidelLehtiniemietal., author = {Netzer, Corinna and Seidel, Lars and Lehtiniemi, Harry and Ravet, Fr{\´e}d{\´e}ric and Mauß, Fabian}, title = {Efficient tracking of knock onset for a wide range of fuel surrogates}, series = {International Multidimensional Engine Modeling User's Group Meeting at the SAE Congress}, booktitle = {International Multidimensional Engine Modeling User's Group Meeting at the SAE Congress}, pages = {6}, language = {en} } @misc{MoshammerSeidelWangetal., author = {Moshammer, Kai and Seidel, Lars and Wang, Yu and Selim, Hatem and Sarathy, S. Mani and Mauß, Fabian and Hansen, Nils}, title = {Aromatic ring formation in opposed-flow diffusive 1, 3-butadiene flames}, series = {Proceedings of the Combustion Institute}, volume = {36}, journal = {Proceedings of the Combustion Institute}, number = {1}, issn = {1540-7489}, doi = {10.1016/j.proci.2016.09.010}, pages = {947 -- 955}, abstract = {This paper is concerned with the formation of one-and two-ring aromatic species in near atmospheric-pressure opposed-flow diffusion flames of 1, 3-butadiene (1, 3-C 4 H 6). The chemical structures of two different 1, 3-C 4 H 6/Ar-O 2/Ar flames were explored using flame-sampling molecular-beam mass spectrometry with both electron and single-photon ionization. We provide mole fraction profiles of 47 components as function of distance from the fuel outlet and compare them to chemically detailed modeling results. To this end, the hierarchically developed model described by Seidel et al.[16] has been updated to accurately comprise the chemistry of 1, 3-butadiene. Generally a very good agreement is observed between the experimental and modeling data, allowing for a meaningful reaction path analysis. With regard to the formation of aromatic species up to naphthalene, it was essential to improve the fulvene …}, language = {en} } @misc{ShresthaSeidelMaussetal., author = {Shrestha, Krishna Prasad and Seidel, Lars and Mauß, Fabian and Zeuch, Thomas}, title = {Kinetic Modeling for NOx prediction with improved base Chemistry}, series = {COST 1404, SMARTCATs, Chemistry of smart energy carriers and technologies, 3rd General Meeting and Workshop on SECs in Industry of SMARTCATs Action}, journal = {COST 1404, SMARTCATs, Chemistry of smart energy carriers and technologies, 3rd General Meeting and Workshop on SECs in Industry of SMARTCATs Action}, language = {en} } @misc{SvenssonLiShamunetal., author = {Svensson, Erik and Li, Changle and Shamun, Sam and Johansson, Bengt and Tuner, Martin and Perlman, Cathleen and Lehtiniemi, Harry and Mauß, Fabian}, title = {Potential Levels of Soot, NOx , HC and CO for Methanol Combustion}, series = {SAE Technical Papers}, journal = {SAE Technical Papers}, number = {2016-01-0887}, issn = {0148-7191}, doi = {10.4271/2016-01-0887}, pages = {17 Seiten}, abstract = {Methanol is today considered a viable green fuel for combustion engines because of its low soot emissions and the possibility of it being produced in a CO2-neutral manner. Methanol as a fuel for combustion engines have attracted interest throughout history and much research was conducted during the oil crisis in the seventies. In the beginning of the eighties the oil prices began to decrease and interest in methanol declined. This paper presents the emission potential of methanol. T-Φ maps were constructed using a 0-D reactor with constant pressure, temperature and equivalence ratio to show the emission characteristics of methanol. These maps were compared with equivalent maps for diesel fuel. The maps were then complemented with engine simulations using a stochastic reactor model (SRM), which predicts end-gas emissions. The SRM was validated using experimental results from a truck engine running in Partially Premixed Combustion (PPC) mode at medium loads. The SRM was able to predict the combustion in terms of pressure trace and rate of heat release. The CO and NOx emissions were matched, however, the HC emissions were underestimated. Finally, the trajectories from the SRM simulations were superimposed on the T-Φ maps to investigate the in engine conditions. The T-Φ map analysis shows that emission of soot are non-existent, formaldehyde can be avoided and that emissions of methane are kept at, compared to diesel combustion, low levels, however CO and NOx levels are similar to diesel combustion. These results were confirmed for engine conditions by the SRM simulations and the engine experiments.}, language = {en} } @misc{FrankenMauss, author = {Franken, Tim and Mauß, Fabian}, title = {Development of Methodology for Predictive Diesel Combustion Simulation Using 0D Stochastic Reactor Model}, series = {SAE Technical Papers}, journal = {SAE Technical Papers}, number = {2016-01-0566}, issn = {0148-7191}, doi = {10.4271/2016-01-0566}, pages = {14 Seiten}, abstract = {Stringent exhaust emission limits and new vehicle test cycles require sophisticated operating strategies for future diesel engines. Therefore, a methodology for predictive combustion simulation, focused on multiple injection operating points is proposed in this paper. The model is designated for engine performance map simulations, to improve prediction of NOx, CO and HC emissions.The combustion process is calculated using a zero dimensional direct injection stochastic reactor model based on a probability density function approach. Further, the formation of exhaust emissions is described using a detailed reaction mechanism for n-heptane, which involves 56 Species and 206 reactions. The model includes the interaction between turbulence and chemistry effects by using a variable mixing time profile. Thus, one is able to capture the effects of mixture inhomogeneities on NOx, CO and HC emission formation.The mixing time model is parameterized using transfer functions for engine operating parameters, e.g., injection mass, injection duration, air fuel ratio, start of injection and speed. These functions are calibrated for nine operating points using multi objective simulated annealing optimization combined with fast running metamodels that speed up the optimization process. The calibrated transfer functions are validated for nine additional operating points. The results for the calibration and validation points show a good match of the combustion heat release rate. Especially the main injection heat release rate is well predicted by the model. The NOx and CO emissions reflect the experimental trends and are in close range to the measurements. Finally, the model is tested for triple injection operating points. The results match the measurements, which show the applicability of the stochastic reactor model in conjunction with the mixing time transfer functions for engine performance map simulations.}, language = {en} } @inproceedings{SeidelNetzerHilbigetal., author = {Seidel, Lars and Netzer, Corinna and Hilbig, Martin and Mauß, Fabian and Klauer, Christian and Pasternak, Michal and Matrisciano, Andrea}, title = {Systematic Reduction of Detailed Chemical Reaction Mechanisms for Engine Applications}, series = {ASME 2016 Internal Combustion Engine Division Fall Technical Conference Greenville, South Carolina, USA, October 9-12, 2016}, booktitle = {ASME 2016 Internal Combustion Engine Division Fall Technical Conference Greenville, South Carolina, USA, October 9-12, 2016}, publisher = {The American Society of Mechanical Engineers}, address = {New York, N.Y.}, isbn = {978-0-7918-5050-3}, pages = {12}, abstract = {In this work we apply a sequence of concepts for mechanism reduction on one reaction mechanism including novel quality control. We introduce a moment based accuracy rating method for species profiles. The concept is used for a necessity based mechanism reduction utilizing 0D reactors. Thereafter a stochastic reactor model (SRM) for internal combustion engines is applied to control the quality of the reduced reaction mechanism during the expansion phase of the engine. This phase is sensitive on engine out emissions, and is often not considered in mechanism reduction work. The proposed process allows to compile highly reduced reaction schemes for CFD application for internal combustion engine simulations. It is demonstrated that the resulting reduced mechanisms predict combustion and emission formation in engines with accuracies comparable to the original detailed scheme.}, language = {en} } @misc{PasternakMaussSensetal., author = {Pasternak, Michal and Mauß, Fabian and Sens, Marc and Riess, Michael and Benz, Andreas and Stapf, Karl Georg}, title = {Gasoline Engine Simulations Using a Zero-Dimensional Spark Ignition Stochastic Reactor Model and Three-Dimensional Computational Fluid Dynamics Engine Model}, series = {International Journal of Engine Research}, volume = {17}, journal = {International Journal of Engine Research}, number = {1}, issn = {1468-0874}, doi = {10.1177/1468087415599859}, pages = {76 -- 85}, abstract = {A simulation process for spark ignition gasoline engines is proposed. The process is based on a zero-dimensional spark ignition stochastic reactor model and three-dimensional computational fluid dynamics of the cold in-cylinder flow. The cold flow simulations are carried out to analyse changes in the turbulent kinetic energy and its dissipation. From this analysis, the volume-averaged turbulent mixing time can be estimated that is a main input parameter for the spark ignition stochastic reactor model. The spark ignition stochastic reactor model is used to simulate combustion progress and to analyse auto-ignition tendency in the end-gas zone based on the detailed reaction kinetics. The presented engineering process bridges the gap between three-dimensional and zero-dimensional models and is applicable to various engine concepts, such as, port-injected and direct injection engines, with single and multiple spark plug technology. The modelling enables predicting combustion effects and estimating the risk of knock occurrence at different operating points or new engine concepts for which limited experimental data are available.}, language = {en} } @misc{LehtiniemiBorgMauss, author = {Lehtiniemi, Harry and Borg, Anders and Mauß, Fabian}, title = {Combustion Modeling of Diesel Sprays}, series = {SAE Technical Papers}, journal = {SAE Technical Papers}, number = {2016-01-0592}, issn = {0148-7191}, doi = {10.4271/2016-01-0592}, pages = {1 -- 11}, abstract = {Several models for ignition, combustion and emission formation under diesel engine conditions for multi-dimensional computational fluid dynamics have been proposed in the past. It has been recognized that the use of a reasonably detailed chemistry model improves the combustion and emission prediction especially under low temperature and high exhaust gas recirculation conditions.The coupling of the combustion chemistry and the turbulent flow can be achieved with different assumptions. In this paper we investigate a selection of n-heptane spray experiments published by the Engine Combustion Network (ECN spray H) with three different combustion models: well-stirred reactor model, transient interactive flamelet model and progress variable based conditional moment closure. All models cater for the use of detailed chemistry, while the turbulence-chemistry interaction modeling and the ability to consider local effects differ.The same chemical mechanism is used by all combustion models, which allows a comparison of ignition delay, flame stabilization and flame lift-off length between the experiments and the results from simulations using the different combustion models. The investigated parameters influence the predictions of computational fluid dynamics simulations of diesel engines. This study indicates that the most reasonable behavior with respect to ignition, flame stabilization and flame structure is predicted by the progress variable based conditional moment closure model.}, language = {en} } @inproceedings{MalliotakisBanyonCurranetal., author = {Malliotakis, Zisis and Banyon, Colin and Curran, Henry J. and Founti, Maria and Keramiotis, Christos and Vourliotakis, George and Koutmos, Panagiotis and Paterakis, George and Souflas, Konstantinos and Mauß, Fabian and Rodriguez Henriquez, Jose Juan and Skevis, George}, title = {A Comperative Study on the Oxidation of Gaseous and Liquid fuels in a Swirlstabilized Flame via Chemiluminescence Measurements}, series = {Book of abtracts, COST SMARTCATs 2nd General Meeting, Lisbon, 14-16th November}, booktitle = {Book of abtracts, COST SMARTCATs 2nd General Meeting, Lisbon, 14-16th November}, publisher = {Cost, European Cooperation in Science and Technology}, pages = {84 -- 85}, language = {en} } @inproceedings{MatriscianoBorgPerlmanetal., author = {Matrisciano, Andrea and Borg, Anders and Perlman, Cathleen and Pasternak, Michal and Seidel, Lars and Netzer, Corinna and Mauß, Fabian and Lehtiniemi, Harry}, title = {Simulation of DI-Diesel combustion using tabulated chemistry approach}, series = {1st Conference on Combustion Processes in Marine and Automotive Engines, 7th - 8th June 2016, Lund, Schweden}, booktitle = {1st Conference on Combustion Processes in Marine and Automotive Engines, 7th - 8th June 2016, Lund, Schweden}, pages = {44 -- 47}, language = {en} } @misc{LocciColinPoitouetal., author = {Locci, Carlo and Colin, Olivier and Poitou, Damien and Mauß, Fabian}, title = {A tabulated, flamelet based no model for large eddy simulations of non premixed turbulent jets with enthalpy loss}, series = {Flow, Turbulence and Combustion}, volume = {94}, journal = {Flow, Turbulence and Combustion}, number = {4}, issn = {1386-6184}, doi = {10.1007/s10494-014-9591-z}, pages = {691 -- 729}, abstract = {Three LES models devoted to the NO prediction in under-adiabatic furnaces are evaluated in this paper: the NORA (NO relaxation Approach) model, based on the NO relaxation towards equilibrium, the linear model (LM) which employs a linear relation to rescale the NO consumption rate, and a new model, DF-NORA, in which the linear approximation of the LM is replaced by a tabulation of the reaction rate as a function of a NO progress variable. To generate this table, NO relaxation complex chemistry calculations are used like in NORA, but the homogeneous reactor is replaced by a steady laminar diffusion flame. These models are validated on Sandia Flame D and on the flameless case of Verissimo et al. (Ener. Fuel. 25, 2469-2480 ([32])). For both cases, NORA underpredicts the NO production due to its insensitivity to strain, while LM overpredicts NO by a factor 2 on Flame D and a factor 13 on the flameless case. DF-NORA presents the best prediction with a maximal underprediction of 30\% on Flame D and an over-prediction of 30\% on the final NO yield of the flameless case. The impact of a radiative source term is also assessed on Flame D, showing a local decrease of NO by less than 7\% compared to the adiabatic calculation for the DF-NORA model.}, language = {en} } @incollection{PasternakMauss, author = {Pasternak, Michal and Mauß, Fabian}, title = {Aspects of Diesel Engine In-Cylinder Processes Simulation Using 0D Stochastic Reactor Model}, series = {Engine processes}, booktitle = {Engine processes}, editor = {Sens, Marc and Baar, Roland}, publisher = {Expert Verlag}, address = {Renningen}, isbn = {978-3-8169-3222-2}, pages = {139}, language = {en} } @inproceedings{RodriguezHenriquezKeramiotisVourliotakisetal., author = {Rodriguez Henriquez, Jose Juan and Keramiotis, Christos and Vourliotakis, George and Mauß, Fabian and Founti, Maria}, title = {An Experimental Investigation of the Effect of Simulated EGR on Typical Gaseous Fuels Mixtures}, series = {1st Conference on Combustion Processes in Marine and Automotive Engines, 7th - 8th June 2016, Lund, Schweden}, booktitle = {1st Conference on Combustion Processes in Marine and Automotive Engines, 7th - 8th June 2016, Lund, Schweden}, pages = {18 -- 21}, language = {en} } @inproceedings{RodriguezHenriquezKeramiotisVourliotakisetal., author = {Rodriguez Henriquez, Jose Juan and Keramiotis, Christos and Vourliotakis, George and Mauß, Fabian and Founti, Maria}, title = {An emission characterization study on a model flame fuelled with natural gas and commercial grade propane}, series = {Proceedings, The MCAA Poster Session - ESOF 2016, EuroScience Open Forum - Manchester, United Kingdom, 24-27 July 2016}, booktitle = {Proceedings, The MCAA Poster Session - ESOF 2016, EuroScience Open Forum - Manchester, United Kingdom, 24-27 July 2016}, editor = {Krstić, Snežana and Cunningham, Paul}, publisher = {MCAA}, address = {Brussels}, isbn = {978-2-9601724-2-3}, pages = {27 -- 28}, language = {en} } @misc{MatriscianoBorgPerlmanetal., author = {Matrisciano, Andrea and Borg, Anders and Perlman, Cathleen and Lehtiniemi, Harry and Pasternak, Michal and Mauß, Fabian}, title = {Soot Source Term Tabulation Strategy for Diesel Engine Simulations with SRM}, series = {SAE Technical Papers}, journal = {SAE Technical Papers}, number = {2015-24-2400}, issn = {0148-7191}, doi = {10.4271/2015-24-2400}, pages = {1 -- 15}, abstract = {In this work a soot source term tabulation strategy for soot predictions under Diesel engine conditions within the zero-dimensional Direct Injection Stochastic Reactor Model (DI-SRM) framework is presented. The DI-SRM accounts for detailed chemistry, in-homogeneities in the combustion chamber and turbulence-chemistry interactions. The existing implementation [1] was extended with a framework facilitating the use of tabulated soot source terms. The implementation allows now for using soot source terms provided by an online chemistry calculation, and for the use of a pre-calculated flamelet soot source term library. Diesel engine calculations were performed using the same detailed kinetic soot model in both configurations. The chemical mechanism for n-heptane used in this work is taken from Zeuch et al. [2] and consists of 121 species and 973 reactions including PAH and thermal NO chemistry. The engine case presented in [1] is used also for this work. The case is a single-injection part-load passenger car Diesel engine with 27 \% EGR fueled with regular Diesel fuel. The two different approaches are analyzed and a detailed comparison is presented for the different soot processes globally and in the mixture fraction space. The contribution of the work presented in this paper is that a method which allows for a direct comparison of soot source terms - calculated online or retrieved from a flamelet table - without any change in the simulation setup has been developed within the SRM framework. It is a unique tool for model development. Our analysis supports our previous conclusion [1] that flamelet soot source terms libraries can be used for multi-dimensional modeling of soot formation in Diesel engines.}, language = {en} } @misc{PasternakMaussXavieretal., author = {Pasternak, Michal and Mauß, Fabian and Xavier, Fabio and Riess, Michael and Sens, Marc and Benz, Andreas}, title = {0D/3D Simulations of Combustion in Gasoline Engines Operated with Multiple Spark Plug Technology}, series = {SAE Technical Papers}, journal = {SAE Technical Papers}, number = {2015-01-1243}, issn = {0148-7191}, doi = {10.4271/2015-01-1243}, abstract = {A simulation method is presented for the analysis of combustion in spark ignition (SI) engines operated at elevated exhaust gas recirculation (EGR) level and employing multiple spark plug technology. The modeling is based on a zero-dimensional (0D) stochastic reactor model for SI engines (SI-SRM). The model is built on a probability density function (PDF) approach for turbulent reactive flows that enables for detailed chemistry consideration. Calculations were carried out for one, two, and three spark plugs. Capability of the SI-SRM to simulate engines with multiple spark plug (multiple ignitions) systems has been verified by comparison to the results from a three-dimensional (3D) computational fluid dynamics (CFD) model. Numerical simulations were carried for part load operating points with 12.5\%, 20\%, and 25\% of EGR. At high load, the engine was operated at knock limit with 0\%, and 20\% of EGR and different inlet valve closure timing. The quasi-3D treatment of combustion chamber geometry and the spherical flame propagation by the 0D SI-SRM enabled for estimating the impact of number of spark plugs on the combustion progress and the risk of knock occurrence. Application of three spark plugs shortened significantly the combustion process. When the engine was operated at knock limit and with 20\% EGR, combustion duration was similar to that of engine operation without EGR and with one spark plug. Overall, the results presented demonstrate that this method has the potential to support early stages of engine development with limited experimental data available.}, language = {en} } @inproceedings{MatriscianoSeidelKlaueretal., author = {Matrisciano, Andrea and Seidel, Lars and Klauer, Christian and Lehtiniemi, Harry and Mauß, Fabian}, title = {An a priori thermodynamic data analysis based chemical lumping method for the reduction of large and multi-component chemical kinetic mechanisms}, series = {5th International Workshop on Model Reduction in Reacting Flows, L{\"u}bbenau, 2015}, booktitle = {5th International Workshop on Model Reduction in Reacting Flows, L{\"u}bbenau, 2015}, pages = {2}, abstract = {A chemical species lumping approach for reduction of large hydrocarbons and oxygenated fuels is presented. The methodology is based on an a priori analysis of the Gibbs free energy of the isomer species which is then used as main criteria for the evaluation of lumped group. Isomers with similar Gibbs free energy are lumped assuming they present equal concentrations when applied to standard reactor conditions. Unlike several lumping approaches found in literature, no calculation results from the primary mechanism have been employed prior to the application of our chemical lumping strategy.}, language = {en} } @inproceedings{SeidelKlauerPasternaketal., author = {Seidel, Lars and Klauer, Christian and Pasternak, Michal and Matrisciano, Andrea and Netzer, Corinna and Hilbig, Martin and Mauß, Fabian}, title = {Systematic Mechanism Reduction for Engine Applications}, series = {5th International Workshop on Model Reduction in Reacting Flows, L{\"u}bbenau, 2015}, booktitle = {5th International Workshop on Model Reduction in Reacting Flows, L{\"u}bbenau, 2015}, pages = {2}, abstract = {In this work we apply various concepts of mechanism reduction with a PDF based method for species profile conservation. The reduction process is kept time efficient by only using 0D and 1D reactors. To account for the expansion phase in internal combustion engines a stochastic engine tool is used to validate the reduction steps.}, language = {en} } @inproceedings{MatriscianoSeidelKlaueretal., author = {Matrisciano, Andrea and Seidel, Lars and Klauer, Christian and Mauß, Fabian and Lehtiniemi, Harry}, title = {An a priori thermodynamic data analysis based on chemical lumping method for the reduction of large and multi-component chemical kinetic mechanisms}, series = {5th Annual Internation Workshop on Model Reduction in Reaction Flows (IWMRRF) L{\"u}bbenau, 28.06-01.07.2015, proceedings}, booktitle = {5th Annual Internation Workshop on Model Reduction in Reaction Flows (IWMRRF) L{\"u}bbenau, 28.06-01.07.2015, proceedings}, pages = {2}, language = {en} } @inproceedings{RodriguezHenriquezSeidelMauss, author = {Rodriguez Henriquez, Jose Juan and Seidel, Lars and Mauß, Fabian}, title = {Plug Flow Reactor Set-up evaluation with methane decomposition at mild conditions and overpressure}, series = {Abstract book, 7th European Combustion Meeting (ECM), Budapest, Hungary, March 30-April 2}, booktitle = {Abstract book, 7th European Combustion Meeting (ECM), Budapest, Hungary, March 30-April 2}, isbn = {978-963-12-1257-0}, language = {en} } @inproceedings{PasternakMaussMatrisciano, author = {Pasternak, Michal and Mauß, Fabian and Matrisciano, Andrea}, title = {Diesel Engine Performance Mapping Using Stochastic Reactor Model}, series = {Proceedings of the 2nd Conference on Engine Processes, July 2-3, 2015, Berlin, Germany}, booktitle = {Proceedings of the 2nd Conference on Engine Processes, July 2-3, 2015, Berlin, Germany}, editor = {Sens, Marc and Baar, Roland}, publisher = {Tech. Univ., Universit{\"a}tsverlag}, address = {Berlin}, isbn = {978-3-7983-2768-9}, pages = {217 -- 232}, language = {en} } @inproceedings{LehtiniemiBorgMauss, author = {Lehtiniemi, Harry and Borg, Andreas and Mauß, Fabian}, title = {Modeling of Spray Combustion under Diesel Engine Conditions}, series = {Proceedings of the 2nd Conference on Engine Processes, July 2-3, 2015, Berlin, Germany}, booktitle = {Proceedings of the 2nd Conference on Engine Processes, July 2-3, 2015, Berlin, Germany}, editor = {Sens, Marc and Baar, Roland}, publisher = {Universit{\"a}tsverlag der TU Berlin}, address = {Berlin}, isbn = {978-3-7983-2768-9}, pages = {217 -- 249}, language = {en} } @misc{MatriscianoPasternakWangetal., author = {Matrisciano, Andrea and Pasternak, Michal and Wang, Xiaoxiao and Antoshkiv, Oleksiy and Mauß, Fabian and Berg, Peter}, title = {On the Performance of Biodiesel Blends - Experimental Data and Simulations Using a Stochastic Fuel Test Bench}, series = {SAE Technical Papers}, journal = {SAE Technical Papers}, number = {2014-01-1115}, issn = {0148-7191}, doi = {10.4271/2014-01-1115}, pages = {1 -- 8}, language = {en} } @inproceedings{SeidelPerlmanFroejdetal., author = {Seidel, Lars and Perlman, Cathleen and Fr{\"o}jd, Karin and Klaus, Anna-Katharina and Laska, Timothy and Jalving, J. and Mauß, Fabian}, title = {CPU Efficient Modelling of Biomass Gasification Using a Stochastic Reactor Approach and Chemistry Guided Reduction}, series = {22nd European Biomass Conference and Exhibition}, booktitle = {22nd European Biomass Conference and Exhibition}, editor = {Seidel, Lars}, language = {en} } @misc{SeidelPerlmanFroejdetal., author = {Seidel, Lars and Perlman, Cathleen and Fr{\"o}jd, Karin and Klaus, Anna-Katharina and Laska, Timothy and Jalving, T. and Mauß, Fabian}, title = {CPU Efficient Modelling of Biomass Gasification Using a Stochastic Reactor Approach and Chemistry Guided Reduction}, pages = {1}, language = {en} } @inproceedings{LehtiniemiBorgMauss, author = {Lehtiniemi, Harry and Borg, Andreas and Mauß, Fabian}, title = {Conditional Moment Closure with a Progress Variable Approach}, series = {COMODIA 2012, proceedings of the Eighth International Conference on Modeling and Diagnostics for Advanced Engine Systems, July 23 - 26, 2012, Fukuoka, Japan}, booktitle = {COMODIA 2012, proceedings of the Eighth International Conference on Modeling and Diagnostics for Advanced Engine Systems, July 23 - 26, 2012, Fukuoka, Japan}, publisher = {JSME}, address = {Tokyo}, pages = {548 -- 553}, language = {en} } @misc{PasternakNakovMaussetal., author = {Pasternak, Michal and Nakov, Galin and Mauß, Fabian and Lehtiniemi, Harry}, title = {Aspects of 0D and 3D Modeling of Soot Formation for Diesel Engines}, series = {Combustion Science and Technology}, volume = {186}, journal = {Combustion Science and Technology}, number = {10-11}, issn = {1563-521X}, doi = {10.1080/00102202.2014.935213}, pages = {1517 -- 1535}, language = {en} } @misc{SchenkLeonMoshammeretal., author = {Schenk, Marina and Leon, Larisa and Moshammer, Kai and Oßwald, Patrick and Kohse-H{\"o}inghaus, Katharina and Zeuch, Thomas and Seidel, Lars and Mauß, Fabian}, title = {Detailed mass spectrometric and modeling study of isomeric butene flames}, series = {Combustion and Flame}, volume = {160}, journal = {Combustion and Flame}, number = {3}, issn = {1556-2921}, pages = {487 -- 503}, language = {en} } @misc{GuentherMauss, author = {G{\"u}nther, Vivien and Mauß, Fabian}, title = {Si(100)2×1 Epitaxy: A Kinetic Monte Carlo Simulation of the Surface Growth}, series = {Physics Procedia}, journal = {Physics Procedia}, number = {40}, issn = {1875-3892}, pages = {56 -- 64}, language = {en} } @inproceedings{MaussTuner, author = {Mauß, Fabian and Tuner, Martin}, title = {"Modelling and Investigation of Exothermic Centers in HCCI Combustion"}, language = {en} } @misc{ZeuchMoreacAhmedetal., author = {Zeuch, Thomas and Mor{\´e}ac, Gladys and Ahmed, Syed Sayeed and Mauß, Fabian}, title = {"A Comprehensive Skeleton Mechanism for the Oxidation of n-heptane Generated by Chemistry Guided Reduction"}, series = {Combustion and Flame}, volume = {155}, journal = {Combustion and Flame}, number = {4}, issn = {0010-2180}, doi = {10.1016/j.combustflame.2008.05.007}, pages = {651 -- 674}, language = {en} } @inproceedings{MaussBoBeck, author = {Mauß, Fabian and Bo, T. and Beck, Linda Maria}, title = {"Detailed Chemistry CFD Engine Combustion Solution with Ignition Progress Variable Approach"}, language = {en} } @inproceedings{MaussTunerKarlsson, author = {Mauß, Fabian and Tuner, Martin and Karlsson, M.}, title = {"Studying HCCI Combustion and its Cyclic Variations versus Heat Transfer, Mixing, and Discretization using a PDF based approach"}, language = {en} } @misc{MaussMosbachSuetal., author = {Mauß, Fabian and Mosbach, Sebastian and Su, Haiyun and Kraft, Markus and Bhave, Amit and Wang, Zhi and Wang, J.-X.}, title = {"Dual Injection Homogeneous Charge Compression Ignition Engine Simulation Using a Stochastic Reactor Model"}, language = {en} } @misc{MaussAhmedMoreacetal., author = {Mauß, Fabian and Ahmed, Syed Sayeed and Mor{\´e}ac, Gladys and Zeuch, Thomas}, title = {"A Comprehensive and Compact n-Heptane Oxidation Model Derived Using Chemical Lumping"}, language = {en} } @inproceedings{AmneusTunerMaussetal., author = {Amn{\´e}us, Per and Tun{\´e}r, Martin and Mauß, Fabian and Collin, Robert and Nygren, Jenny and Richter, Mattias and Ald{\´e}n, Marcus and Kraft, Markus and Bhave, Amit and Hildingsson, Leif and Johansson, Bengt}, title = {"Formaldehyd and Hydroxyl Radicals in an HCCI Engine - Calculations and Measurements"}, doi = {10.4271/2007-01-0049}, language = {en} } @inproceedings{EbenezerMauss, author = {Ebenezer, N. and Mauß, Fabian}, title = {A robust and adaptive method for model chemical kinetics based on PRISM and ISAT philosophies}, series = {Proceedings - 3rd European Combustion Meeting, ECM 2007, Mediterranean Agronomic Institute of Chania, Crete, Greece, 11 - 13 April 2007}, booktitle = {Proceedings - 3rd European Combustion Meeting, ECM 2007, Mediterranean Agronomic Institute of Chania, Crete, Greece, 11 - 13 April 2007}, publisher = {The Combustion Institute, Greek Section}, address = {Chania}, language = {en} } @article{MaussLehtiniemiBalthasaretal., author = {Mauß, Fabian and Lehtiniemi, Harry and Balthasar, M. and Magnusson, I.}, title = {Modelling Diesel Spray Ignition Using Detailed Chemistry with a Flamelet Progress Variable Approach}, language = {en} } @misc{MaussSuVikhanskyetal., author = {Mauß, Fabian and Su, Haiyun and Vikhansky, Alexander and Mosbach, Sebastian and Kraft, Markus and Bhave, Amit and Kim, Kyoung-Oh and Kobayashi, Tatsuo}, title = {"A computational Study of an HCCI Engine With Direct Injection During Gas Exchange"}, doi = {10.1016/j.combustflame.2006.07.005}, language = {en} } @misc{MaussBhaveKraftetal., author = {Mauß, Fabian and Bhave, Amit and Kraft, Markus and Montorsi, Luca}, title = {"Sources of CO emissions in an HCCI engine: A numerical analysis"}, doi = {10.1016/j.combustflame.2005.10.015}, language = {en} } @inproceedings{ZeuchAhmedMoreacetal., author = {Zeuch, Thomas and Ahmed, Syed Sayeed and Mor{\´e}ac, Gladys and Mauß, Fabian}, title = {Modellierung der Verbrennung von n-Heptan mit detaillierten und reduzierten Reaktionsmechanismen {\"u}ber weite Temperatur- und Druckerbereiche}, series = {Hauptthema "Heterogene Katalyse: Br{\"u}cke zwischen Ideal- und Realsystemen" mit Industrie-Symposium "Br{\"u}ckenschl{\"a}ge zwischen idealen und realen Systemen in der heterogenen Katalyse"}, booktitle = {Hauptthema "Heterogene Katalyse: Br{\"u}cke zwischen Ideal- und Realsystemen" mit Industrie-Symposium "Br{\"u}ckenschl{\"a}ge zwischen idealen und realen Systemen in der heterogenen Katalyse"}, publisher = {Dt. Bunsen-Ges. f{\"u}r Physikalische Chemie}, address = {Frankfurt am Main}, language = {de} } @article{MaussMoreacBlurock, author = {Mauß, Fabian and Mor{\´e}ac, Gladys and Blurock, Edward S.}, title = {Automatic Generation of a Detailed Mechanism for the Oxidation of n-Decane}, language = {en} } @incollection{MaussBlurockLehtiniemietal., author = {Mauß, Fabian and Blurock, Edward S. and Lehtiniemi, Harry and Gogan, Adina}, title = {"Speed-up of a stochastic reactor model for a hydrogen fueled SI-engine by PRISM"}, language = {en} } @inproceedings{MaussAhmediSundenetal., author = {Mauß, Fabian and Ahmedi, Abdelhadi and Sund{\´e}n, Bengt and Gogan, Adina and Lehtiniemi, Harry}, title = {"Analysis of an Extended Ionization Equilibrium in the Post-flame Gases for Spark Ignited Combustion"}, doi = {10.1115/ICEF2004-0922}, language = {en} } @misc{MaussBhaveKraftetal., author = {Mauß, Fabian and Bhave, Amit and Kraft, Markus and Oakley, Aaron and Zhao, Hua}, title = {"Evaluating the EGR-AFR Operating Range of a HCCI Engine"}, language = {en} } @incollection{MaussPrieschingSaricetal., author = {Mauß, Fabian and Priesching, Peter and Saric, Fikret and Bauer, W. and Schmid, M. and Leipertz, Alfred}, title = {"Partikelgr{\"o}ssenverteilungen in Dieselmotoren - Detaillierte kinetische Berechnungen und Experimentelle Untersuchungen"}, language = {de} } @inproceedings{MaussLehtiniemiAmneusetal., author = {Mauß, Fabian and Lehtiniemi, Harry and Amn{\´e}us, Per and Balthasar, M. and Karlsson, A. and Magnusson, I. and Gogan, Adina and Sund{\´e}n, Bengt}, title = {Modelling Diesel Spray Ignition Using Detailed Chemistry with a Flamelet Progress Variable Approach}, language = {en} } @inproceedings{MaussMoreacBlurocketal., author = {Mauß, Fabian and Mor{\´e}ac, Gladys and Blurock, Edward S. and Gogan, Adina and Sund{\´e}n, Bengt and Lehtiniemi, Harry}, title = {Automatic Generation of a Detailed Mechanism for the Oxidation of n-Decane}, language = {en} } @inproceedings{MaussLehtiniemiBalthasaretal., author = {Mauß, Fabian and Lehtiniemi, Harry and Balthasar, M. and Magnusson, I.}, title = {Modeling Diesel Engine Combustion with Detailed Chemistry using a Progress Variable Approach}, series = {Powertrain \& Fluid Systems conference and exhibition, San Antonio, Texas USA, October 24 - 27, 2005}, booktitle = {Powertrain \& Fluid Systems conference and exhibition, San Antonio, Texas USA, October 24 - 27, 2005}, publisher = {SAE International}, address = {Warrendale, Pa.}, language = {en} } @inproceedings{MaussTunerBlurock, author = {Mauß, Fabian and Tuner, Martin and Blurock, Edward S.}, title = {"Phase Optimized Skeleton Mechanisms for Stochastic Reactor Models for Engine Simulation"}, language = {en} } @misc{PrieschingTatschlMaussetal., author = {Priesching, Peter and Tatschl, Reinhard and Mauß, Fabian and Saric, Fikret and Netzell, Karl and Bauer, W. and Schmidt, Markus L. and Leipertz, Alfred and Merola, Simona Silvia and Vaglieco, Bianca Maria}, title = {Soot Particle Size Distribution - a Joint Work for Kinetic Modelling and Experimental Investigations}, series = {SAE Technical Papers}, journal = {SAE Technical Papers}, number = {2005-24-053}, issn = {0148-7191}, pages = {1 -- 8}, abstract = {The intention of the presented work was to develop a new simulation tool that fits into a CFD (computational fluid dynamics) workflow and provides information about the soot particle size distribution. Additionally it was necessary to improve and use state-of-the-art measurement techniques in order to be able to gain more knowledge about the behavior of the soot particles and to validate the achieved simulation results. The work has been done as a joint research financed by the European Community under FP5.}, language = {en} } @inproceedings{BellancaMaussWang, author = {Bellanca, R. and Mauß, Fabian and Wang, H.}, title = {Automatic optimization of detailed kinetic mechanism for HCCI-engine simulation}, series = {The 227th ACS National Meeting, Anaheim, CA, March 28-April 1, 2004}, booktitle = {The 227th ACS National Meeting, Anaheim, CA, March 28-April 1, 2004}, publisher = {American Chemical Society}, address = {Washington, DC}, pages = {267 -- 268}, abstract = {In recent years detailed kinetic models have been developed and validated for both auto ignition and laminar combustion processes. The range of validity of these models is limited by the range of physical parameters covered by the available experimental data. Often, a re-optimization of the models is necessary. Optimization of reaction models has been automated in the past for example for the development of the GRI-Mech. In this work a similar procedure has been applied to optimize a gasoline fuel reference model as developed by Curran and Westbrook for HCCI engine cases. The HCCI-process was simulated using a compressed homogeneous reactor. Computations have been carried out on a PC in a graphical user interface environment. Experimental data were collected at Lund Institute of Technology on a Volvo engine with variable compression ratio and port injection mixes of iso-octane/n-heptane. Results show that, after optimization, HCCI experiments can be predicted for the given conditions.}, language = {en} } @inproceedings{AhmedMoreacZeuchetal., author = {Ahmed, Syed Sayeed and Mor{\´e}ac, Gladys and Zeuch, Thomas and Mauß, Fabian}, title = {Efficient lumping technique for the automatic generation of n-heptane and iso-octane oxidation mechanism}, series = {227th ACS National meeting, Anaheim, CA, March 28-April 1, 2004}, booktitle = {227th ACS National meeting, Anaheim, CA, March 28-April 1, 2004}, publisher = {American Chemical Society}, address = {Washington, DC}, pages = {265 -- 266}, abstract = {The aim of this work is to generate a semi-detailed mechanism for the oxidation of n-heptane and iso-octane mixture with 241 species and 1905 reactions and to optimize it for the different engine operating conditions to cover the full range of temperature. A step wise efficient lumping strategy for different reaction types combine with necessity analysis has been used for the simplification and reduction of mechanism in order to make it faster and less complex in terms of both number of reactions and species. Its validation has been done against the shock tube experimental data from Fieweger et al. for both low and high temperature regions, lean and rich fuel conditions, a range of octane numbers and pressures from 13 bar to 40 bar. In addition, the mechanism was tested using a zero dimensional Homogenous Charge Compression Ignition engine model against experiments under a range of different octane numbers and initial temperatures.}, language = {en} } @inproceedings{PrieschingSaricMaussetal., author = {Priesching, Peter and Saric, Fikret and Mauß, Fabian and Bauer, W. and Schmid, M. and Leipertz, Alfred}, title = {Partikelgr{\"o}ßenverteilung in Dieselmotoren - Detaillierte kinetische Berechnungen und Experimentelle Untersuchungen}, series = {Motorische Verbrennung, aktuelle Probleme und moderne L{\"o}sungsans{\"a}tze, VII. Tagung im Haus der Technik e.V., M{\"u}nchen, 15./16. M{\"a}rz 2005}, booktitle = {Motorische Verbrennung, aktuelle Probleme und moderne L{\"o}sungsans{\"a}tze, VII. Tagung im Haus der Technik e.V., M{\"u}nchen, 15./16. M{\"a}rz 2005}, editor = {Leipertz, Alfred}, publisher = {ESYTEC Energie- u. Systemtechnik}, address = {Erlangen}, isbn = {3-931901-36-X}, pages = {287 -- 298}, language = {de} } @misc{MaussBhaveBalthasaretal., author = {Mauß, Fabian and Bhave, Amit and Balthasar, M. and Kraft, Markus}, title = {"Analysis of a Natural Gas Fuelled HCCI Engine with Exhaust Gas Recirculation Using a Stochastic Reactor Model"}, doi = {10.1243/146808704772914273}, language = {en} } @inproceedings{MontorsiMaussBianchietal., author = {Montorsi, Luca and Mauß, Fabian and Bianchi, Gian Marco and Bhave, Amit and Kraft, Markus}, title = {Analysis of the HCCI Combustion of a Turbocharged Truck Engine Using a Stochastic Reactor Model}, series = {Design, application, performance and emissions of modern internal combustion engine systems and components, proceedings of the 2003 spring technical conference of the ASME Internal Combustion Engine Division, Salzburg, Austria, May 11 - 14, 2003}, booktitle = {Design, application, performance and emissions of modern internal combustion engine systems and components, proceedings of the 2003 spring technical conference of the ASME Internal Combustion Engine Division, Salzburg, Austria, May 11 - 14, 2003}, publisher = {ASME}, address = {New York, NY}, isbn = {0-7918-3678-9}, pages = {235 -- 246}, language = {en} } @inproceedings{LovasBlurockMauss, author = {Lovas, Terese and Blurock, Edward S. and Mauß, Fabian}, title = {Towards Dynamically Reduced Mechanisms based on Domain Splitting}, series = {Computational fluid and solid mechanics 2003, proceedings Second MIT Conference on Computational Fluid and Solid Mechanics, June 17 - 20, 2003}, booktitle = {Computational fluid and solid mechanics 2003, proceedings Second MIT Conference on Computational Fluid and Solid Mechanics, June 17 - 20, 2003}, editor = {Bathe, Klaus-J{\"u}rgen}, publisher = {Elsevier}, address = {Amsterdam [u.a.]}, isbn = {978-0-08-044046-0}, pages = {1430 -- 1433}, language = {en} } @inproceedings{MaussAhmediFrankeetal., author = {Mauß, Fabian and Ahmedi, Abdelhadi and Franke, A. and Soyhan, H. S. and Sund{\´e}n, Bengt}, title = {"Prediction Tool for the Ion Current in SI-Combustion"}, language = {en} } @article{MaussHoyermannZeuch, author = {Mauß, Fabian and Hoyermann, K. and Zeuch, Thomas}, title = {"A Detailed Kinetic Mechanism for the Oxidation of Hydrocarbons and its Application to the Analysis of Benzene Formation in Fuel Rich Premixed Laminar Acetylene and Propene Flames"}, language = {en} } @inproceedings{MaussAhmedMoreacetal., author = {Mauß, Fabian and Ahmed, Syed Sayeed and Mor{\´e}ac, Gladys and Zeuch, Thomas}, title = {"Automatic reduction of n-heptane and iso-octane oxidation mechanism using necessity analysis"}, language = {en} } @inproceedings{MaussGoganSundenetal., author = {Mauß, Fabian and Gogan, Adina and Sund{\´e}n, Bengt and Lehtiniemi, Harry}, title = {"Stochastic Model for the Investigation of the Influence of Turbulent Mixing on Engine Knock"}, language = {en} } @article{MaussLovasHasseetal., author = {Mauß, Fabian and L{\o}v{\aa}s, Terese and Hasse, C. and Peters, Norbert}, title = {"Development of Adaptive Kinetics for Application in Combustion Systems"}, language = {en} } @misc{MaussBalthasarPfitzneretal., author = {Mauß, Fabian and Balthasar, M. and Pfitzner, M. and Mack, A.}, title = {Implementation and Validation of a New Soot Model and Application to Industrial Aero-engine Combustor}, series = {Journal of engineering for gas turbines and power}, volume = {124}, journal = {Journal of engineering for gas turbines and power}, number = {1}, issn = {0742-4795}, pages = {66 -- 75}, language = {en} } @inproceedings{BlurockLovasMauss, author = {Blurock, Edward S. and Lovas, Terese and Mauß, Fabian}, title = {Steady State Reduced Mechanisms based on Domain Splitting}, series = {Proceedings of the 19th International Conference on the Dynamics of Explosions and Reactive Systems, Hakone, July 27 - August 1, 2003}, booktitle = {Proceedings of the 19th International Conference on the Dynamics of Explosions and Reactive Systems, Hakone, July 27 - August 1, 2003}, address = {Hakone}, language = {en} } @inproceedings{LovasBlurockMauss, author = {Lovas, Terese and Blurock, Edward S. and Mauß, Fabian}, title = {Automatic Reduced Mechanisms based on Domain Splitting Methods}, series = {Proceedings of the European Combustion Meeting "ECM 2003", Orl{\´e}ans, France, October 25-28, 2003}, booktitle = {Proceedings of the European Combustion Meeting "ECM 2003", Orl{\´e}ans, France, October 25-28, 2003}, address = {Orl{\´e}ans}, language = {en} } @article{MaussBalthasarWang, author = {Mauß, Fabian and Balthasar, M. and Wang, H.}, title = {"Numerical Simulation of Thermo-Ionisation of Soot Particles and its Effect on Soot Growth in Laminar Premixed Flames"}, language = {en} } @inproceedings{MaussStenlaasGoganetal., author = {Mauß, Fabian and Stenl{\aa}{\aa}s, Ola and Gogan, Adina and Egnell, Rolf and Sund{\´e}n, Bengt}, title = {"The Influence of NO on the Occurrence of Autoignition in the End Gas of SI-Engines"}, language = {en} } @article{MaussBalthasarKnobeletal., author = {Mauß, Fabian and Balthasar, M. and Knobel, A. and Kraft, M.}, title = {"Soot Formation in turbulent Reacting flows - A PDF Based Approach"}, language = {en} } @article{MaussNilsson, author = {Mauß, Fabian and Nilsson, D.}, title = {A Comprehensive Kinetic Model for Staged Combustion of Nitrogen doped Fuels}, language = {en} } @inproceedings{MaussErlandssonEinewalletal., author = {Mauß, Fabian and Erlandsson, O. and Einewall, P. and Johansson, B. and Amn{\´e}us, Per}, title = {"Simulation of HCCI - addressing compression ratio and turbo charging"}, language = {en} } @misc{BalthasarMaussWang, author = {Balthasar, M. and Mauß, Fabian and Wang, H.}, title = {A computational study of the thermal ionization of soot particles and its effect on their growth in laminar premixed flames}, series = {Combustion and Flame}, volume = {129}, journal = {Combustion and Flame}, number = {1-2}, issn = {1556-2921}, doi = {10.1016/S0010-2180(02)00344-9}, pages = {204 -- 216}, language = {en} } @incollection{MaussJohansson, author = {Mauß, Fabian and Johansson, B.}, title = {"Homogeneous Charge Compression Ignition Engines: A Review on Experiments and Numerical Investigations"}, language = {en} } @inproceedings{MaussSoyhanLovas, author = {Mauß, Fabian and Soyhan, H. S. and L{\o}v{\aa}s, Terese}, title = {"A Stochastic Simulation of an HCCI Engine Using an Automatically Reduced Mechanism"}, language = {en} } @inproceedings{MaussHajirezaSunden, author = {Mauß, Fabian and Hajireza, S. and Sund{\´e}n, Bengt}, title = {"Effect of Inhomogeneities in the End Gas Temperature Field on the Autoignition in SI Engines"}, language = {en} } @misc{MaussKraftMaigaardetal., author = {Mauß, Fabian and Kraft, Markus and Maigaard, Peter and Christensen, Bengt and Johansson, B.}, title = {Investigation of Combustion Emissions in a HCCI Engine-Measurements and a New Computational Model}, series = {Proceedings of the Combustion Institute}, volume = {28}, journal = {Proceedings of the Combustion Institute}, number = {1}, issn = {1540-7489}, pages = {1195 -- 1201}, language = {en} } @misc{MaussHajirezaSunden, author = {Mauß, Fabian and Hajireza, S. and Sund{\´e}n, Bengt}, title = {Hot Spot Autoignition in SI Engines}, series = {Proceedings of the Combustion Institute}, volume = {28}, journal = {Proceedings of the Combustion Institute}, number = {1}, issn = {1540-7489}, pages = {1169 -- 1175}, language = {en} } @incollection{MaussNilssonLovasetal., author = {Mauß, Fabian and Nilsson, Daniel and L{\o}v{\aa}s, Terese and Amn{\´e}us, Per}, title = {"Reduction of Complex Fuel Chemistry for Simulation of Combustion in HCCI Engines"}, language = {en} } @inproceedings{MaussHajirezaSunden, author = {Mauß, Fabian and Hajireza, S. and Sund{\´e}n, Bengt}, title = {"A Three-Zone Model for Investigation of Gas Behavior in the Combustion Chamber of SI Engines in Relation to Knock"}, language = {en} } @misc{MaussDedrichsBalthasar, author = {Mauß, Fabian and Dedrichs, A. S. and Balthasar, M.}, title = {Modeling of NOx and Soot Formation in Diesel Combustion}, series = {Oil \& Gas Science and Technology}, volume = {54}, journal = {Oil \& Gas Science and Technology}, number = {2}, issn = {0020-2274}, pages = {245 -- 249}, language = {en} } @incollection{MaussKraftBalthasar, author = {Mauß, Fabian and Kraft, M. and Balthasar, M.}, title = {Soot and NOx Formation in a Stationary Turbulent Combustor}, language = {en} } @misc{MaussBaiFuchs, author = {Mauß, Fabian and Bai, X. S. and Fuchs, L.}, title = {Laminar Flamelet Structure at Low and Vanishing Scalar Dissipation Rate}, series = {Combustion and flame}, volume = {120}, journal = {Combustion and flame}, number = {3}, issn = {0010-2180}, pages = {285 -- 300}, language = {en} } @inproceedings{MaussAmneusNilssonetal., author = {Mauß, Fabian and Amn{\´e}us, Per and Nilsson, D. and Christensen, Magnus and Johansson, Bengt}, title = {"Modeling of Wall Quenching in Homogeneous Charge Compression Ignition Engines"}, language = {en} } @misc{BaiFuchsBalthasaretal., author = {Bai, X. S. and Fuchs, L. and Balthasar, M. and Mauß, Fabian}, title = {Detailed Kinetic Soot Modeling in Turbulent Jet Diffusion Flames}, series = {Symposium (International) on Combustion}, volume = {27}, journal = {Symposium (International) on Combustion}, number = {2}, issn = {0082-0784}, pages = {1623 -- 1630}, language = {en} } @inproceedings{MaussHajirezaSunden, author = {Mauß, Fabian and Hajireza, S. and Sund{\´e}n, Bengt}, title = {"Two-Zone Model of Gas Thermodynamic State in SI Engines with Relevance for Knock"}, language = {en} } @incollection{MaussBalthasar, author = {Mauß, Fabian and Balthasar, M.}, title = {"Simplification of a Detailed Kinetic Soot Model for Application in 3-D Programs"}, language = {en} } @incollection{MaussBalthasar, author = {Mauß, Fabian and Balthasar, M.}, title = {"Simplification Strategy for a Detailed Chemical Soot Model"}, language = {en} } @inproceedings{MaussSaitzkoffReinmannetal., author = {Mauß, Fabian and Saitzkoff, A. and Reinmann, R. and Glavmo, M.}, title = {"In-Cylinder Pressure Measurements Using the spark Plug as an Ionization Sensor"}, language = {en} } @inproceedings{MaussReinmannSaitzkoff, author = {Mauß, Fabian and Reinmann, R. and Saitzkoff, A.}, title = {"Local Air-Fuel Ratio Measurements Using the Spark Plug as an Ionization Sensor"}, language = {en} } @incollection{MaussNilsson, author = {Mauß, Fabian and Nilsson, D.}, title = {Staged Combustion of Nitrogen doped Fuels}, language = {en} } @article{MaussTichyBjorgeetal., author = {Mauß, Fabian and Tichy, F. E. and Bj{\o}rge, T. and Magnussen, B. F. and Bengtsson, P.-E.}, title = {"Two-dimensional Imaging of Glyoxal in a Turbulent Acetylene Diffusion Flame"}, language = {en} } @inproceedings{MaussBoodBengtssonetal., author = {Mauß, Fabian and Bood, J. and Bengtsson, P.-E. and Burgdorf, K. and Debbratt, I.}, title = {"Knock in Spark-Ignition Engines: End-Gas Temperature Measurements Using Rotational CARS and Detailed Kinetic Calculations of the Autoignition Process"}, language = {en} } @misc{MarquardMaussJungfleischetal., author = {Marquard, M. and Mauß, Fabian and Jungfleisch, B. and Suntz, R. and Bockhorn, Henning}, title = {Re-initiation of Soot Surface Growth in Premixed Counterflow Flames}, series = {Symposium (International) on Combustion}, volume = {26}, journal = {Symposium (International) on Combustion}, number = {2}, issn = {0082-0784}, pages = {2343 -- 2350}, language = {en} } @misc{BalthasarHeylMaussetal., author = {Balthasar, M. and Heyl, A. and Mauß, Fabian and Schmitt, Frank and Bockhorn, Henning}, title = {Flamelet Modeling of Soot Formation in Laminar Ethylene Air Diffusion Flames}, series = {Symposium (International) on Combustion}, volume = {26}, journal = {Symposium (International) on Combustion}, number = {2}, issn = {0082-0784}, pages = {2369 -- 2377}, language = {en} } @incollection{MaussSchaeferBockhorn, author = {Mauß, Fabian and Sch{\"a}fer, T. and Bockhorn, Henning}, title = {"Bildung und Oxidation von Ruß in vorgemischten Gegenstromflammen"}, language = {de} } @incollection{MaussTrilkenBreitbachetal., author = {Mauß, Fabian and Trilken, B. and Breitbach, H. and Peters, Norbert}, title = {"Soot Formation in Partially Premixed Diffusion Flames at Atmospheric Pressure"}, language = {en} } @misc{MaussSchaeferBockhorn, author = {Mauß, Fabian and Sch{\"a}fer, T. and Bockhorn, Henning}, title = {Inception and Growth of Soot Particles in Dependence on the Surrounding Gas Phase}, series = {Combustion and flame}, volume = {99}, journal = {Combustion and flame}, number = {3/4}, issn = {0010-2180}, pages = {697 -- 705}, language = {en} } @misc{MaussSchaeferBockhornetal., author = {Mauß, Fabian and Sch{\"a}fer, T. and Bockhorn, Henning and Fetting, F.}, title = {Surface Growth of Soot Particles under Flame Conditions}, series = {Zeitschrift f{\"u}r Naturforschung}, journal = {Zeitschrift f{\"u}r Naturforschung}, number = {50a}, pages = {S. 1009}, language = {en} } @misc{MaussBockhorn, author = {Mauß, Fabian and Bockhorn, Henning}, title = {Numerical Calculation of Soot Formation in Premixed Hydrocarbon Flames}, series = {ACS Division Proceedings Online}, volume = {39}, journal = {ACS Division Proceedings Online}, number = {1}, pages = {S. 172}, language = {en} } @incollection{MaussBreitbachGoettgensetal., author = {Mauß, Fabian and Breitbach, H. and G{\"o}ttgens, J. and Pitsch, H. and Peters, Norbert}, title = {"Experimentelle und numerische Untersuchungen des Einflusses der Gasphase auf die Rußbildung"}, language = {de} } @incollection{MaussPetersRoggetal., author = {Mauß, Fabian and Peters, Norbert and Rogg, Bernd and Williams, F. A.}, title = {Reduced Kinetic Mechanisms for Premixed Hydrogen Flames}, series = {Reduced Kinetic Mechanisms for Applications in Combustion Systems}, booktitle = {Reduced Kinetic Mechanisms for Applications in Combustion Systems}, editor = {Peters, Norbert and Rogg, Bernd}, publisher = {Springer}, address = {Berlin [u.a.]}, isbn = {978-3-540-56372-3}, pages = {29 -- 43}, language = {en} } @misc{BreitbachGoettgensMaussetal., author = {Breitbach, H. and G{\"o}ttgens, J. and Mauß, Fabian and Pitsch, H. and Peters, Norbert}, title = {Laminar Counterflow Mixing of Acetylene into Hot Combustion Products}, series = {Symposium (International) on Combustion}, volume = {25}, journal = {Symposium (International) on Combustion}, number = {1}, issn = {0082-0784}, pages = {1357 -- 1364}, language = {en} } @incollection{KennelMaussPeters, author = {Kennel, C. and Mauß, Fabian and Peters, Norbert}, title = {Reduced Kinetic Mechanisms for Premixed Propane-Air Flames}, series = {Reduced kinetic mechanisms for applications in combustion systems}, booktitle = {Reduced kinetic mechanisms for applications in combustion systems}, editor = {Peters, Norbert}, publisher = {Springer}, address = {Berlin [u.a.]}, isbn = {3-540-56372-5}, pages = {123 -- 141}, language = {en} } @incollection{MaussPeters, author = {Mauß, Fabian and Peters, Norbert}, title = {Reduced Kinetic Mechanisms for Premixed Methane-Air Flames}, series = {Reduced kinetic mechanisms for applications in combustion systems}, booktitle = {Reduced kinetic mechanisms for applications in combustion systems}, editor = {Peters, Norbert}, publisher = {Springer}, address = {Berlin [u.a.]}, isbn = {3-540-56372-5}, pages = {58 -- 75}, language = {en} } @incollection{MaussGoettgens, author = {Mauß, Fabian and G{\"o}ttgens, J.}, title = {"Flamelet Libraries - Description of the Data Format and Catalogue of Existing Libraries"}, language = {en} } @misc{MaussBalakrishnanTrevino, author = {Mauß, Fabian and Balakrishnan, G. and Trevi{\~n}o, C.}, title = {The Asymptotic Structure of Hydrogen-Air Diffusion Flames}, series = {Combustion and flame}, volume = {91}, journal = {Combustion and flame}, number = {3/4}, issn = {0010-2180}, pages = {246 -- 256}, language = {en} } @misc{BanyonRodriguezHenriquezPaterakisetal., author = {Banyon, Colin and Rodriguez Henriquez, Jose Juan and Paterakis, George and Malliotakis, Zisis and Souflas, Konstantinos and Keramiotis, Christos and Vourliotakis, George and Mauß, Fabian and Curran, Henry J. and Skevis, George and Koutmos, Panagiotis and Founti, Maria}, title = {A comparative study of the effect of varied reaction environments on a swirl stabilized flame geometry via optical measurements}, series = {Fuel : the science and technology of fuel and energy}, volume = {216}, journal = {Fuel : the science and technology of fuel and energy}, issn = {0016-2361}, doi = {10.1016/j.fuel.2017.09.105}, pages = {826 -- 834}, abstract = {The present work is a part of a larger experimental campaign which examines the behaviour of various fuels on a swirl stabilized flame burner configuration. Overall, detailed speciation measurements and temperature measurements were combined with optical measurements. The work presented here concerns the part of the experimental campaign which deals with the optical characteristics of the examined flames. The work adds to the growing database of experimental measurements assessing engine-relevant reaction environments which shift from traditional ones in order to meet pollutant emission regulations and efficiency standards. Here, the oxidation of several commonly used fuel and fuel surrogates that are subjected to the addition of a bio-derived fuel additive (dimethyl ether) and emulated exhaust gas recirculation (EGR) is studied in a laboratory-scale swirl …}, language = {en} } @misc{ShresthaMaiGirietal., author = {Shrestha, Krishna Prasad and Mai, Tam V.-T. and Giri, Sushant and Giri, Binod Raj and Huynh, Lam Kim and Mauss, Fabian}, title = {Reaction Kinetics of NH2 Radicals with Dimethyl Ether (DME) and Diethyl Ether (DEE) and Their Implications in NH3-DME/DEE blend modeling}, series = {Los Alamos National Laboratory (LANL)}, journal = {Los Alamos National Laboratory (LANL)}, number = {LA-UR-23-26969}, abstract = {The reactions of amino radicals (NH2) play a vital role in governing the combustion behaviour of various nitrogen-rich chemical systems such as ammonia, coal nitrogen gasification, and biomass. Ammonia has recently gained considerable attention in the combustion community. Since it is a carbon-free fuel, it can help combat global warming by decarbonizing the energy sectors. However, several reports in the literature highlight the importance of the NH3-dual fuel approach to boost the combustion properties of neat ammonia. For combustion modeling of NH3-dual fuel systems, accurate knowledge of the cross-reactions between the nitrogen and carbon family is very critical. Several earlier studies have shown the influence of NH2 radical reactions with the fuel (combustion promoter) in accurately predicting the low- temperature combustion behaviour of NH3-dual fuels (see Giri et al. and references cited therein). The reactions of NH2 radicals are not only important in the combustion environment but also, they are relevant to the chemistry of planetary atmospheres. In this work, we investigated the hydrogen abstraction reactions of NH2 radials with dimethyl ether (DME) and diethyl ether (DEE) using a high-level quantum method combined with the statistical rate theory. We implemented the derived rate coefficients in our kinetic model to identify its effect in the combustion modeling of NH3-DME/DEE blends.}, language = {en} } @misc{ElbazGiriShresthaetal., author = {Elbaz, Ayman M. and Giri, Binod Raj and Shrestha, Krishna Prasad and Arab, Omar Z. and Farooq, Aamir and Mauß, Fabian and Roberts, William L.}, title = {A comprehensive experimental and kinetic modeling study of laminar flame propagation of ammonia blended with propene}, series = {Combustion and Flame}, volume = {253}, journal = {Combustion and Flame}, issn = {0010-2180}, doi = {10.1016/j.combustflame.2023.112791}, abstract = {Enhancement of ammonia reactivity is crucial for potential applications of ammonia as an engine and gas turbine fuel. A common strategy for improving ammonia's poor reactivity is blending it with more reactive fuels like hydrogen and methane. However, fundamental studies of ammonia combustion with higher hydrocarbons and key intermediate oxidation species of higher alkanes such as propene do not exist. Thus, this work presents an effort to study the laminar flame propagation of ammonia blended with propene. Laminar burning velocity (SL) of NH3/C3H6/air mixtures was measured at 298 K, pressures up to 5 bar, equivalence ratios of 0.7 to 1.3, and various propene to ammonia ratios (i.e.,\% propene to ammonia mole fraction, xC3H6 = 10 to 50) in a high-pressure spherical propagating flame vessel. A kinetic model was developed based on our previous work to characterize the combustion behavior of NH3/C3H6/air mixture. The model reasonably agrees with the experimental data and follows the observed trends very well. The results showed that blending NH3 with C3H6 positively enhanced SL of NH3 by promoting the formation of key radicals e.g., O, OH, and H. Relative to a neat ammonia/air mixture, co-firing ammonia with propene leads to a reduced pressure dependence of the laminar burning velocity. However, the reaction H + O2(+M)=HO2(+M) leads to strong pressure dependency of lean NH3/C3H6 mixtures compared to rich mixtures. The model reveals that besides fuel-NO coming from NH3, prompt NO also actively contributes to NO formation. It is seen that N2O formation is significantly suppressed with increasing pressure or increasing C3H6 content in the fuel blend. In contrast to NO and N2O, NO2 concentration increases slightly with an increase in pressure. The reported experimental data and model will be useful in understanding the interaction between NH3 and alkenes.}, language = {en} } @misc{FotiadisAsimakopoulouBaltzopoulouetal., author = {Fotiadis, Kyriakos and Asimakopoulou, Akrivi and Baltzopoulou, Penelope and Kastrinaki, Georgia and Koutsonikolas, Dimitrios and Karagiannakis, George and Skevis, George and Richter, Jana and Mauß, Fabian}, title = {Experimental Characterization of a Novel Foam Burner Design for the Low-Excess-Enthalpy Combustion of Very Lean Syngas Mixtures}, series = {Energies}, volume = {16}, journal = {Energies}, number = {19}, issn = {1996-1073}, doi = {/10.3390/en16197014}, pages = {7014}, abstract = {In the present work, a novel foam burner design is proposed and experimentally evaluated for operation with highly diluted syngas mixtures. The lab-scale burner consists of a purpose-built, square-shaped, high-temperature-grade stainless steel tubular reactor filled with square-sectioned siliconized silico carbide (SiSiC) foams. The assembly was installed in an electrical furnace. Spatially resolved temperature measurements were obtained along the reactor axis, while simultaneous measurements of CO, CO2, H2, O2, and N2 were taken at the burner exit and the water levels were recorded upstream and downstream of the reactor. The results clearly show that flames can be stabilized along the reactor for a range of foam characteristics and operating conditions. Hydrogen conversion efficiencies in excess of 98\%, and overall thermal efficiencies close to 95\% were achieved for the selected operating conditions. Overall, the denser 10 ppi foam demonstrated superior combustion characteristics in terms of stability, lower enthalpy rises, and a wider operating range at the expense of a very modest pressure drop penalty. Finally, scanning electron microscopy, coupled with energy dispersion spectroscopy (SEM/EDS) and Raman spectroscopy analyses, was used to determine the morphological and compositional characteristics of the pristine and aged foams. After more than 100 h of operation, no significant performance degradation was observed, even though the burner design was subjected to considerable thermal stress.}, language = {en} } @misc{ShresthaElbazGirietal., author = {Shrestha, Krishna Prasad and Elbaz, Ayman M. and Giri, Binod Raj and Arab, Omar Z. and Adil, Mohammad and Seidel, Lars and Roberts, William L. and Farooq, Aamir and Mauß, Fabian}, title = {Experimental and Kinetic Modeling Study of 1, 3-Dioxolane Oxidation and Comparison with Dimethoxymethane}, series = {Energy \& Fuels}, volume = {36}, journal = {Energy \& Fuels}, number = {14}, issn = {1520-5029}, doi = {10.1021/acs.energyfuels.2c01132}, pages = {7744 -- 7754}, abstract = {This work reports laminar flame speeds and ignition delay times of 1,3-dioxolane/O2/inert gases over a wide range of conditions. Laminar flame speeds were determined experimentally at pressures of 1 and 3 bar, the temperature of 300 K, and equivalence ratios ranging from 0.7 to 1.4 using a constant-volume spherical chamber, whereas ignition delay times were measured in a shock tube at a pressure of 1 bar, the temperature range of 1000-1265 K, and equivalence ratios of 0.5 and 1.0. A detailed kinetic model is developed to predict the oxidation of 1,3-dioxolane utilizing our new experimental data and published datasets on the oxidation of 1,3-dioxolane in freely propagating flames, autoignition in rapid compression machines and shock tubes, and speciation in a jet-stirred reactor. Model predictions are in reasonable agreement with the experimental data. Laminar flame speeds and ignition delay times of 1,3-dioxolane (cyclic ether) are compared with those of dimethoxymethane (acyclic ether). It is found that 1,3-dioxolane has a higher laminar flame speed than that of dimethoxymethane, which may be attributed to the formation of C2H4, C2H2, and the H atom from 1,3-dioxolane. On the contrary, ignition delay times of 1,3-dioxolane are longer than those of dimethoxymethane below 1000 K and shorter above 1000 K for the same dilution level. The reaction ȮCHO = CO2 + H is critical for accurately predicting 1,3-dioxolane oxidation, and it significantly influences model predictions under low-pressure conditions. The model developed in this work will serve as the base mechanism for higher cyclic and acyclic ethers.}, language = {en} } @misc{GiriShresthaMaietal., author = {Giri, Binod Raj and Shrestha, Krishna Prasad and Mai, Tam V.-T. and Mauß, Fabian and Huynh, Lam Kim}, title = {A theoretical kinetic study of the reactions of NH2 radicals with methanol and ethanol and their implications in kinetic modeling}, series = {International Journal of Chemical Kinetics}, volume = {55}, journal = {International Journal of Chemical Kinetics}, number = {1}, issn = {0538-8066}, doi = {10.1002/kin.21609}, pages = {3 -- 14}, abstract = {Amino (NH2) radicals play a central role in the pyrolysis and oxidation of ammonia. Several reports in the literature highlight the importance of the reactions of NH2 radicals with fuel in NH3-dual-fuel combustion. Therefore, we investigated the reactions of NH2 radicals with methanol (CH3OH) and ethanol (C2H5OH) theoretically. We explored the various reaction pathways by exploiting CCSD(T)/cc-pV(T, Q)Z//M06-2X/aug-cc-pVTZ level of theory. The reaction proceeds via complex formation at the entrance and exit channels in an overall exothermic process. We used canonical transition state theory to obtain the high-pressure limiting rate coefficients for various channels over the temperature range of 300-2000 K. We discerned the role of various channels in the potential energy surface (PES) of NH2 + CH3OH/C2H5OH reactions. For both reactions, the hydrogen abstraction pathway at the OH-site of alcohols plays a minor role in the entire T-range investigated. By including the title reactions into an extensive kinetic model, we demonstrated that the reaction of NH2 radicals with alcohols plays a paramount role in accurately predicting the low-temperature oxidation kinetics of NH3-alcohols dual fuel systems (e.g., shortening the ignition delay time). On the contrary, these reactions have negligible importance for high-temperature oxidation kinetics of NH3-alcohol blends (e.g., not affecting the laminar flame speed). In addition, we calculated the rate coefficients for NH2 + CH4 = CH3 + NH3 reaction that are in excellent agreement with the experimental data.}, language = {en} } @misc{GiriShresthaMaietal., author = {Giri, Binod Raj and Shrestha, Krishna Prasad and Mai, Tam V.-T. and Giri, Sushant and Adil, Mohammad and Naik, R. Thirumaleswara and Mauß, Fabian and Huynh, Lam Kim}, title = {A Theoretical Study of NH2 Radical Reactions with Propane and Its Kinetic Implications in NH3-Propane Blends' Oxidation}, series = {Energies}, volume = {16}, journal = {Energies}, number = {16}, issn = {1996-1073}, doi = {10.3390/en16165943}, abstract = {The reaction of NH2 radicals with C3H8 is crucial for understanding the combustion behavior of NH3/C3H8 blends. In this study, we investigated the temperature dependence of the rate coefficients for the hydrogen abstraction reactions of C3H8 by NH2 radicals using high-level theoretical approaches. The potential energy surface was constructed at the CCSD(T)/cc-pV(T, Q)//M06-2X/aug-cc-pVTZ level of theory, and the rate coefficients were computed using conventional transition state theory, incorporating the corrections for quantum tunneling and hindered internal rotors (HIR). The computed rate coefficients showed a strong curvature in the Arrhenius behavior, capturing the experimental literature data well at low temperatures. However, at T > 1500 K, the theory severely overpredicted the experimental data. The available theoretical studies did not align with the experiment at high temperatures, and the possible reasons for this discrepancy are discussed. At 300 K, the reaction of NH2 with C3H8 predominantly occurs at the secondary C-H site, which accounts for approximately 95\% of the total reaction flux. However, the hydrogen abstraction reaction at the primary C-H site becomes the dominant reaction above 1700 K. A composite kinetic model was built, which incorporated the computed rate coefficients for NH2 + C3H8 reactions. The importance of NH2 + C3H8 reactions in predicting the combustion behavior of NH3/C3H8 blends was demonstrated by kinetic modeling.}, language = {en} } @misc{ShresthaEckartDrostetal., author = {Shrestha, Krishna Prasad and Eckart, Sven and Drost, Simon and Fritsche, Chris and Schießl, Robert and Seidel, Lars and Maas, Ulrich and Krause, Hartmut and Mauß, Fabian}, title = {A comprehensive kinetic modeling of oxymethylene ethers (OMEn, n= 1-3) oxidation-laminar flame speed and ignition delay time measurements}, series = {Combustion and Flame}, volume = {246}, journal = {Combustion and Flame}, issn = {1556-2921}, doi = {10.1016/j.combustflame.2022.112426}, abstract = {This work reports on the development and experimental validation of a detailed reaction mechanism for the oxidation of polyoxymethylene dimethyl ethers (OMEn, n = 1-3). The validation is done by constant-volume chamber laminar flame speeds (393 K and 443 K, 1 to 5 bar, and equivalence ratio 0.8 to 1.6) and Rapid Compression Machine ignition delay times (550-680 K, 10 and 15 bar, equivalence ratios of 0.5-2.0) in OMEn/air mixtures. Using our new experimental and published data, the validation basis for the new kinetic model comprises the pyrolysis and oxidation of OMEn (n = 1-3) in freely propagating flames, auto-ignition in rapid compression machines and shock tubes, and speciation in jet-stirred and flow reactors as well as burner-stabilized premixed flames. The model provides a reasonable agreement with the experimental data for a broad range of conditions investigated. The performance of the developed model is compared against the recent literature models. OMEn (n = 1-3) all have the same laminar flame speed. The model suggests that the chemistry of OME0 (DME) and CH3OCHO (methyl formate) is the one that dictates the flame chemistry. Under the same pressure and equivalence ratio conditions, ignition delay times of OME2 and OME3 are similar for the investigated temperature range. This work helps to improve the understanding of OMEs chemistry. The model developed in this work will serve as the base mechanism for higher chain length OMEs (n>3).}, language = {en} } @misc{DavidAgnewBanaresAlcantaraetal., author = {David, William I. F. and Agnew, Gerry D. and Ba{\~n}ares-Alc{\´a}ntara, Ren{\´e} and Barth, James and Hansen, John Bogild and Br{\´e}quigny, Pierre and De Joannon, Mara and F{\"u}rstenberg Stott, Sofia and F{\"u}rstenberg Stott, Conor and Guati-Rojo, Andrea and Hatzell, Marta and MacFarlane, Douglas R. and Makepeace, Joshua W. and Mastorakos, Epaminondas and Mauß, Fabian and Medford, Andrew and Mounaim-Rousselle, Christine and Nowicki, Duncan A. and Picciani, Mark A. and Postma, Rolf S. and Rouwenhorst, Kevin H. R. and Sabia, Pino and Salmon, Nicholas and Simonov, Alexandr N. and Smith, Collin and Torrente-Murciano, Laura and Valera-Medina, Augustin}, title = {2023 Roadmap on ammonia as a carbon-free fuel}, series = {Journal of Physics: Energy}, volume = {6}, journal = {Journal of Physics: Energy}, number = {2}, issn = {2515-7655}, doi = {10.1088/2515-7655/ad0a3a}, abstract = {The 15 short chapters that form this 2023 ammonia-for-energy roadmap provide a comprehensive assessment of the current worldwide ammonia landscape and the future opportunities and associated challenges facing the use of ammonia, not only in the part that it can play in terms of the future displacement of fossil-fuel reserves towards massive, long-term, carbon-free energy storage and heat and power provision, but also in its broader holistic impacts that touch all three components of the future global food-water-energy nexus.}, language = {en} } @misc{MantePrehnTheileetal., author = {Mante, Till and Prehn, Sascha and Theile, Martin and Seidel, Lars and Mestre, Laura and Buchholz, Bert and Mauß, Fabian}, title = {Investigation of An Ammonia Diesel Dual-Fuel Combustion Process on a Heavy-Duty Single Cylinder Research Engine for the Development of Suitable Simulation Tools for Maritime Applications}, series = {Heavy-Duty-, On- und Off-Highway-Motoren 2022 : Stand der Energiewende im Heavy-Duty-Bereich}, journal = {Heavy-Duty-, On- und Off-Highway-Motoren 2022 : Stand der Energiewende im Heavy-Duty-Bereich}, editor = {Heintzel, Alexander}, publisher = {Springer Vieweg}, address = {Wiesbaden}, isbn = {978-3-658-41477-1}, doi = {10.1007/978-3-658-41477-1_3}, pages = {24 -- 39}, abstract = {This paper discusses the adaption of a single cylinder research engine for a retrofit application with an ammonia diesel dual-fuel combustion process and the build of an ammonia fuel system. The gaseous ammonia will be injected in the air intake pipe and the premixed ammonia air mixture will enter the combustion chamber. The diesel injection is carried out via a high-pressure common rail system. All relevant parameters can be freely adjusted via a freely programmable control unit. With the help of experimental data from a single cylinder research engine at the chair of piston machines and internal combustion engines of the University of Rostock (LKV), a dual-fuel combustion model based on detailed chemistry will be developed and optimized. This model will be integrated in a full research engine model, which ensures the best possible representation of the real engine. The combustion model is being developed by LOGE Deutschland GmbH. The full research engine model is developed by FVTR GmbH. The analysis of the combustion process starts with pure diesel operating points and is successively substituted by ammonia in the course of the measurement campaigns. Both the combustion characteristics are relevant, as they significantly influence the resulting performance and engine operation, as well as the exhaust emissions, as the carbon emissions can be reduced, but the nitrogen oxides and ammonia slip increase significantly in relevance due to the ammonia. The results obtained will be used to derive initial recommendations for action and to estimate the potential for application in the inland waterway shipping. In addition, the development of the systematic simulation tools covers a broad spectrum of research questions and aims to increase the efficiency of the necessary R\&D.}, language = {en} } @misc{HilbigMalliotakisSeideletal., author = {Hilbig, Martin and Malliotakis, Zisis and Seidel, Lars and Vourliotakis, George and Keramiotis, Christos and Mauß, Fabian and Founti, Maria}, title = {The effect of base chemistry choice in a generated n-hexane oxidation model using an automated mechanism generator}, series = {International Journal of Chemical Kinetics}, volume = {51}, journal = {International Journal of Chemical Kinetics}, number = {10}, issn = {1097-4601}, doi = {10.1002/kin.21309}, pages = {786 -- 798}, abstract = {The present study describes the utilization of a reaction mechanism generator for the development of chemical kinetic models. The aim of the investigation is twofold. The in-house developed mechanism generator is updated with reaction classes reported in the literature, and the effect of the lower hydrocarbon chemistry, that is, base chemistry, on the generation process is assessed. For this purpose, the algorithm is implemented on two different base chemistry mechanisms, that have previously been validated against a different range of hydrocarbons, that is, the mechanisms of the groups coauthoring the study. n-Hexane has been used as a modeling target due to its important role in combustion studies as a surrogate for engine and aviation applications. The steps of the generation process are given in detail as this is the first time the current algorithm is utilized. The two generated mechanisms are compared against speciation data, ignition delay times, and flame velocities from the literature. The overall agreement of the generated mechanisms is satisfying; discrepancies exist in the negative temperature coefficient regime. Reaction path analysis and sensitivity analysis were performed, revealing the reactions that cause the different mechanism performance. Among others, the study reveals that the generated schemes pose a fast and adequate alternative to literature mechanisms; it is however evident that the latter may include more detailed reaction paths and are therefore superior in terms of validation.}, language = {en} } @misc{VanTreekLubranoLavaderaSeideletal., author = {Van Treek, Lisa and Lubrano Lavadera, Marco and Seidel, Lars and Mauß, Fabian and Konnov, Alexander A.}, title = {Experimental and modelling study of laminar burning velocity of aqueous ethanol}, series = {Fuel}, volume = {257}, journal = {Fuel}, issn = {1873-7153}, doi = {10.1016/j.fuel.2019.116069}, abstract = {Laminar burning velocities of ethanol-water-air mixtures have been determined using the heat flux method. Aqueous ethanol contained 0-40\% of water by mole fraction. Laminar premixed flat flames were stabilized on a perforated burner under adiabatic conditions for the equivalence ratio range from 0.7 to 1.4. Burning velocity measurements were performed for the initial gas temperature of 358 K and at atmospheric pressure. The results for ethanol-air flames are in good agreement with the previous data obtained using the same heat flux method. The present and literature experimental data were compared against predictions using four different kinetic models. All models show uniform behaviour over the range of ethanol dilution by water covered in the present study. However, model predictions significantly diverge from the experimental data obtained in spherical flames. To quantify the effect of dilution on the laminar burning velocity, an empirical dimensionless correlation has been derived from the experimental data and predictions of the models tested. Further numerical analyses were performed to identify the effects of water addition on laminar burning velocities. Results suggested that water strongly interacts with the H2/O2 and C1 oxidation/recombination routes.}, language = {en} } @misc{VanTreekRothSeideletal., author = {Van Treek, Lisa and Roth, Norbert and Seidel, Lars and Mauß, Fabian}, title = {Measurements of the laminar burning velocities of rich ethylene/air mixtures}, series = {Fuel}, volume = {275}, journal = {Fuel}, issn = {0016-2361}, doi = {10.1016/j.fuel.2020.117938}, pages = {9}, abstract = {Laminar burning velocities of premixed ethylene/air flames were investigated under fuel lean and rich conditions. The laminar burning velocities were measured with the heat flux method at atmospheric pressure and unburnt gas temperatures of 298 K. The measurements have been performed for the equivalence ratio range of Φ = 0.7-2.5 using stabilized and flat flames on a perforated burner plate under adiabatic conditions. This is the first time that experimental measurements with the heat flux method of the ethylene/air flames under super fuel rich conditions are performed. The experimental data were compared against predictions using three different kinetic models and published flame speed. The measured flame speeds agree with other published data within the error margin. The experimental and predicted laminar flames do agree at fuel lean conditions, but there are some notable discrepancies under fuel rich conditions.}, language = {en} } @misc{VanTreekRothSeideletal., author = {Van Treek, Lisa and Roth, Norbert and Seidel, Lars and Mauß, Fabian}, title = {Laminar burning velocities of rich ethylene / air flames}, abstract = {The laminar burning velocity SL of a given mixture of fuel and oxidizer is an important parameter to characterize premixed flames. SL is not only a fundamental parameter to calculate properties of turbulent flames, it is also an important target for the development of chemical kinetic mechanisms. Under fuel rich conditions it has relevance when simulating soot formation in burner stabilized flames. Many experiments on soot formation have been conducted in fuel-rich burner stabilized ethylene flames. Therefore an interest exists in experimental data for laminar burning velocity, in particular in fuel-rich ethylene flames. In the present work, ethylene / air flames were measured in the heat flux setup. Subsequently, the experimental data were compared against existing data and modelled using two kinetic models.}, language = {en} } @misc{VanTreekLubranoLavaderaKonnovetal., author = {Van Treek, Lisa and Lubrano Lavadera, Marco and Konnov, Alexander A. and Seidel, Lars and Mauß, Fabian}, title = {Measurements of the laminar burning velocities of ethanol-water-air flames}, abstract = {The laminar burning velocity of ethanol-water-air flames at atmospheric pressure and initial gas temperatures of T = 358 K was measured with the heat flux method. The mixture of ethanol-water-air contained 0\%, 10\%, 20\%, 30\% and 40\% water by mole and the equivalence ratio (ϕ) range was varied from 0.7 to 1.4. The experiments were compared against predictions using three different kinetic models.}, language = {en} } @inproceedings{BenslerMontefrancescoWillandetal., author = {Bensler, H. and Montefrancesco, Emanuela and Willand, J. and Bo, T. and Risi, A. and Mauß, Fabian and Netzell, Karl}, title = {Prediction on non-premixed combustion and soot formation using and interactive flamelet approach}, series = {Conference proceedings, Conference on Thermo- and Fluid Dynamic Processes in Diesel Engines, September 12th - 15th 2006, Valencia, Spain}, booktitle = {Conference proceedings, Conference on Thermo- and Fluid Dynamic Processes in Diesel Engines, September 12th - 15th 2006, Valencia, Spain}, publisher = {Univ. Polit{\´e}cnica}, address = {Valencia}, isbn = {84-9705-982-4}, pages = {339 -- 352}, language = {en} } @inproceedings{MarchalMoreacNetzelletal., author = {Marchal, C. and Mor{\´e}ac, Gladys and Netzell, Karl and Kasper, M. and Mauß, Fabian}, title = {The pressure dependence of soot particle size distribution functions}, series = {Proceedings - 3rd European Combustion Meeting, ECM 2007, Mediterranean Agronomic Institute of Chania, Crete, Greece, 11 - 13 April 2007}, booktitle = {Proceedings - 3rd European Combustion Meeting, ECM 2007, Mediterranean Agronomic Institute of Chania, Crete, Greece, 11 - 13 April 2007}, publisher = {The Combustion Institute, Greek Section}, address = {Chania}, language = {en} } @article{MaussNetzellLehtiniemi, author = {Mauß, Fabian and Netzell, Karl and Lehtiniemi, Harry}, title = {"Calculating the Soot Particle Size Distribution Function in Turbulent Diffusion Flames using a Sectional Method"}, language = {en} } @inproceedings{MaussLehtiniemiNetzell, author = {Mauß, Fabian and Lehtiniemi, Harry and Netzell, Karl}, title = {Calculating soot in a turbulent jet diffision flame using the unsteady flamelet model}, series = {Proceedings of the European Combustion Meeting, Louvain-la-Neuve, Belgium, April 3 - 6, 2005}, booktitle = {Proceedings of the European Combustion Meeting, Louvain-la-Neuve, Belgium, April 3 - 6, 2005}, publisher = {Combustion Inst.}, address = {Louvain-la-Neuve}, language = {en} } @inproceedings{MaussNetzellLehtiniemietal., author = {Mauß, Fabian and Netzell, Karl and Lehtiniemi, Harry and Gogan, Adina and Sund{\´e}n, Bengt}, title = {Aspects of Modeling Soot Formation in Turbulent Diffusion Flames}, language = {en} } @incollection{MaussNetzellMachaletal., author = {Mauß, Fabian and Netzell, Karl and Machal, C. and Mor{\´e}ac, Gladys}, title = {"Modelling the Soot Particle Size Distribution Functions Using a Detailed Kinetic Soot Model and a Sectional Model"}, language = {en} } @misc{WenzelGezginSteineretal., author = {Wenzel, Paul and Gezgin, A. and Steiner, R{\"u}diger and Kr{\"u}ger, Christian and Netzell, Karl and Lehtiniemi, Harry and Mauß, Fabian}, title = {Modeling of the soot particle size distribution in diesel engines}, series = {Conference proceedings, Conference on Thermo- and Fluid Dynamic Processes in Diesel Engines, September 12th - 15th 2006, Valencia, Spain}, journal = {Conference proceedings, Conference on Thermo- and Fluid Dynamic Processes in Diesel Engines, September 12th - 15th 2006, Valencia, Spain}, publisher = {Univ. Polit{\´e}cnica}, address = {Valencia}, isbn = {84-9705-982-4}, pages = {397 -- 410}, language = {en} } @inproceedings{SamuelssonGoganNetzelletal., author = {Samuelsson, K. and Gogan, Adina and Netzell, Karl and Lehtiniemi, Harry and Sund{\´e}n, Bengt and Mauß, Fabian}, title = {Modeling Diesel Engine Combustion and Pollutant Formation using a Stochastic Reactor Model Approach}, series = {Book of abstracts, Fifth Symposium Towards Clean Diesel Engines, 2 - 3 June 2005, Lund, Sweden}, booktitle = {Book of abstracts, Fifth Symposium Towards Clean Diesel Engines, 2 - 3 June 2005, Lund, Sweden}, publisher = {Univ., Lund Institute of Technology}, address = {Lund}, language = {en} } @article{MaussNetzellLehtiniemi, author = {Mauß, Fabian and Netzell, Karl and Lehtiniemi, Harry}, title = {"Aspects of Modeling Soot Formation in Turbulent Diffusion Flames"}, language = {en} } @misc{MaiBuiNhungetal., author = {Mai, Tam V.-T. and Bui, Thanh Q. and Nhung, Nguyen Thi Ai and Quy, Phan Tu and Shrestha, Krishna Prasad and Mauß, Fabian and Giri, Binod Raj and Huynh, Lam Kim}, title = {An Ab Initio RRKM-Based Master Equation Study for Kinetics of OH-Initiated Oxidation of 2-Methyltetrahydrofuran and Its Implications in Kinetic Modeling}, series = {Energies}, volume = {16}, journal = {Energies}, number = {9}, issn = {1996-1073}, doi = {10.3390/en16093730}, abstract = {Cyclic ethers (CEs) can be promising future biofuel candidates. Most CEs possess physico-chemical and combustion indicators comparable to conventional fuels, making them suitable for internal combustion engines. This work computationally investigates the kinetic behaviors of hydrogen abstraction from 2-methyl tetrahydrofuran (2MTHF), one of the promising CEs, by hydroxyl radicals under combustion and atmospheric relevant conditions. The various reaction pathways were explored using the CCSD(T)/cc-pVTZ//M06-2X/aug-cc-pVTZ level of theory. The Rice-Ramsperger-Kassel-Marcus-based master equation (RRKM-ME) rate model, including treatments for hindered internal rotation and tunneling, was employed to describe time-dependent species profiles and pressure and temperature-dependent rate coefficients. Our kinetic model revealed that the H-abstraction proceeds via an addition-elimination mechanism forming reaction complexes at both the entrance and exit channels. Eight different reaction channels yielding five radical products were located. The reaction exhibited complex kinetics yielding a U-shaped Arrhenius behavior. An unusual occurrence of negative temperature dependence was observed at low temperatures, owing to the negative barrier height for the hydrogen abstraction reaction from the C-H bond at the vicinity of the O-atom. A shift in the reaction mechanism was observed with the dominance of the abstraction at Cα-H of 2MTHF ring (causing negative-T dependence) and at CH3 (positive-T dependence) at low and high temperatures, respectively. Interestingly, the pressure effect was observed at low temperatures, revealing the kinetic significance of the pre-reaction complex. Under atmospheric pressure, our theoretical rate coefficients showed excellent agreement with the available literature data. Our model nicely captured the negative temperature-dependent behaviors at low temperatures. Our predicted global rate coefficients can be expressed as k (T, 760 Torr) = 3.55 × 101 × T-4.72 × exp [-340.0 K/T] + 8.21 × 10-23 × T3.49 × exp [918.8 K/T] (cm3/molecule/s). Our work provides a detailed kinetic picture of the OH-initiated oxidation kinetics of 2MTHF. Hence, this information is useful for building a kinetic me chanism for methylated cyclic ethers.}, language = {en} } @misc{FrankenDugganMatriscianoetal., author = {Franken, Tim and Duggan, Alexander and Matrisciano, Andrea and Lehtiniemi, Harry and Borg, Anders and Mauß, Fabian}, title = {Multi-Objective Optimization of Fuel Consumption and NO x Emissions with Reliability Analysis Using a Stochastic Reactor Model}, series = {SAE Technical Paper}, journal = {SAE Technical Paper}, issn = {0148-7191}, doi = {10.4271/2019-01-1173}, abstract = {The introduction of a physics-based zero-dimensional stochastic reactor model combined with tabulated chemistry enables the simulation-supported development of future compression-ignited engines. The stochastic reactor model mimics mixture and temperature inhomogeneities induced by turbulence, direct injection and heat transfer. Thus, it is possible to improve the prediction of NOx emissions compared to common mean-value models. To reduce the number of designs to be evaluated during the simulation-based multi-objective optimization, genetic algorithms are proven to be an effective tool. Based on an initial set of designs, the algorithm aims to evolve the designs to find the best parameters for the given constraints and objectives. The extension by response surface models improves the prediction of the best possible Pareto Front, while the time of optimization is kept low. This work presents a novel methodology to couple the stochastic reactor model and the Non-dominated Sorting Genetic Algorithm. First, the stochastic reactor model is calibrated for 10 low, medium and high load operating points at various engine speeds. Second, each operating point is optimized to find the lowest fuel consumption and specific NOx emissions. The optimization input parameters are the temperature at intake valve closure, the compression ratio, the start of injection, the injection pressure and exhaust gas recirculation rate. Additionally, it is ensured that the maximum peak cylinder pressure and turbine inlet temperature are not exceeded. This enables a safe operation of the engine and exhaust aftertreatment system under the optimized conditions. Subsequently, a reliability analysis is performed to estimate the effect of off-nominal conditions on the objectives and constraints. The novel multi-objective optimization methodology has proven to deliver reasonable results. The zero-dimensional stochastic reactor model with tabulated chemistry is a fast running physics-based model that allow to run large optimization problems in a short amount of time. The combination with the reliability analysis also strengthens the confidence in the simulation-based optimized engine operation parameters.}, language = {en} } @misc{RossiBargendeKulzeretal., author = {Rossi, Edoardo and Bargende, Michael and Kulzer, Andr{\´e} Casal and Chiodi, Marco and Massoud, Ehab and Shrestha, Krishna Prasad and Mauß, Fabian}, title = {Analysis of the applicability of Water Injection in Combination with an eFuel for Knock Mitigation and Improved Engine Efficiency}, series = {SAE Technical Paper}, journal = {SAE Technical Paper}, issn = {2688-3627}, doi = {10.4271/2022-37-0019}, abstract = {The development of future gasoline engines is dominated by the study of new technologies aimed at reducing the engine negative environmental impact and increase its thermal efficiency. One common trend is to develop smaller engines able to operate in stoichiometric conditions across the whole engine map for better efficiency, lower fuel consumption, and optimal conversion rate of the three-way catalyst (TWC). Water injection is one promising technique, as it significantly reduces the engine knock tendency and avoids fuel enrichment for exhaust temperature mitigation at high power operation. With the focus on reducing the carbon footprint of the automotive sector, another vital topic of research is the investigation of new alternative CO2-neutral fuels or so-called eFuels. Several studies have already shown how these new synthetic fuels can be produced by exploiting renewable energy sources and can significantly reduce engine emissions. This work is part of the FVV project number 1367, "Water Injection in Spark-Ignition Engines II", which investigates the coexistence of two different engine technologies that heads towards the same direction of sustainability of the internal combustion engine: water injection and eFuels. The goal is to assess the advantages that the adoption of an eFuel in combination with water injection strategies can bring, with respect to the same strategies applied in combination with commercial gasoline. Several water injection strategies, including direct water injection, indirect water injection, injection timing, and pressure variations, are considered for a better understanding of the benefits brought by the combination of an eFuel with water injection. For this purpose, experimental tests and 3D-CFD engine simulations have been performed. The physical properties of the investigated eFuel have been experimentally measured for accurate modelling in the simulation environment, and the thermodynamic properties have been evaluated utilizing detailed chemistry calculations.}, language = {en} } @misc{MatriscianoNetzerWerneretal., author = {Matrisciano, Andrea and Netzer, Corinna and Werner, Adina and Borg, Anders and Seidel, Lars and Mauß, Fabian}, title = {A Computationally Efficient Progress Variable Approach for In-Cylinder Combustion and Emissions Simulations}, series = {SAE Technical Paper}, journal = {SAE Technical Paper}, issn = {0148-7191}, doi = {10.4271/2019-24-0011}, abstract = {The use of complex reaction schemes is accompanied by high computational cost in 3D CFD simulations but is particularly important to predict pollutant emissions in internal combustion engine simulations. One solution to tackle this problem is to solve the chemistry prior the CFD run and store the chemistry information in look-up tables. The approach presented combines pre-tabulated progress variable-based source terms for auto-ignition as well as soot and NOx source terms for emission predictions. The method is coupled to the 3D CFD code CONVERGE v2.4 via user-coding and tested over various speed and load passenger-car Diesel engine conditions. This work includes the comparison between the combustion progress variable (CPV) model and the online chemistry solver in CONVERGE 2.4. Both models are compared by means of combustion and emission parameters. A detailed n-decane/α-methyl-naphthalene mechanism, comprising 189 species, is used for both online and tabulated chemistry simulations. The two chemistry solvers show very good agreement between each other and equally predict trends derived experimentally by means of engine performance parameters as well as soot and NOx engine-out emissions. The CPV model shows a factor 8 speed-up in run-time compared to the online chemistry solver without compromising the accuracy of the solution.}, language = {en} } @misc{KurapatiBorgSeideletal., author = {Kurapati, Vinaykumar Reddy and Borg, Anders and Seidel, Lars and Mauß, Fabian}, title = {SprayLet: One-Dimensional Interactive Cross-Sectionally Averaged Spray Model}, series = {SAE Technical Paper}, journal = {SAE Technical Paper}, issn = {0148-7191}, doi = {10.4271/2023-24-0083}, abstract = {Spray modeling is among the main aspects of mixture formation and combustion in internal combustion engines. It plays a major role in pollutant formation and energy efficiency although adequate modeling is still under development. Strong grid dependence is observed in the droplet-based stochastic spray model commonly used. As an alternative, an interactive model called 'SprayLet' is being developed for spray simulations based on one-dimensional integrated equations for the gas and liquid phases, resulting from cross-sectionally averaging of multi-dimensional transport equations to improve statistical convergence. The formulated one-dimensional cross-section averaged system is solved independently of the CFD program to provide source terms for mass, momentum and heat transfer between the gas and liquid phases. The transport processes take place in a given spray cone where the nozzle exit is automatically resolved. In the 1D program, the conservation equations are for droplet diameter, droplet temperature, as well as for continuity and momentum of the liquid and the gaseous phase are solved. The source terms between the phases are conservatively embedded into the spray region of the CFD program. In CFD program, the transport equations are solved for gas phase only. The SprayLet model is validated using standard Sandia sprays by comparing penetration lengths and fuel mixture fractions with experimental data.}, language = {en} } @inproceedings{MaussSoyhanAmneusetal., author = {Mauß, Fabian and Soyhan, Hakan Serhad and Amn{\´e}us, Per and L{\o}v{\aa}s, Terese and Nilsson, Daniel and Maigaard, Peter and Sorusbay, Cem}, title = {"Automatic Reduction of Detailed Chemical Reaction Mechanisms for Autoignition under SI Engine Conditions"}, language = {en} } @misc{Turquandd'AuzayShapiroProuvieretal., author = {Turquand d'Auzay, Charles and Shapiro, Evgeniy and Prouvier, Matthieu and Winkler, Axel and Seidel, Lars and Borg, Anders and Mauß, Fabian}, title = {Evaluation of Fast Detailed Kinetics Calibration Methodology for 3D CFD Simulations of Spray Combustion}, series = {SAE Technical Paper}, journal = {SAE Technical Paper}, number = {2022-01-1042}, issn = {0148-7191}, doi = {10.4271/2022-01-1042}, abstract = {Meeting strict current and future emissions legislation necessitates development of computational tools capable of predicting the behaviour of combustion and emissions with an accuracy sufficient to make correct design decisions while keeping computational cost of the simulations amenable for large-scale design space exploration. While detailed kinetics modelling is increasingly seen as a necessity for accurate simulations, the computational cost can be often prohibitive, prompting interest in simplified approaches allowing fast simulation of reduced mechanisms at coarse grid resolutions appropriate for internal combustion engine simulations in design context. In this study we present a simplified Well-stirred Reactor (WSR) implementation coupled with 3D CFD Ricardo VECTIS solver. A detailed evaluation of benchmark ECN spray problem is presented demonstrating that a single point calibration of such a model using a bulk reaction multiplier approach can provide correct representation of the solution across a wide range of temperatures on grid sizes typically employed for RANS internal combustion engine simulations with tabulated kinetics or zonal combustion models.}, language = {en} } @misc{MannaSabiaShresthaetal., author = {Manna, Maria Virginia and Sabia, Pino and Shrestha, Krishna Prasad and Seidel, Lars and Ragucci, Raffaele and Mauß, Fabian and De Joannon, Mara}, title = {NH3NO interaction at low-temperatures: an experimental and modeling study}, series = {Proceedings of the Combustion Institute}, volume = {39}, journal = {Proceedings of the Combustion Institute}, number = {1}, issn = {1873-2704}, doi = {10.1016/j.proci.2022.09.027}, pages = {775 -- 784}, abstract = {The present work provides new insight into NH3single bondNO interaction under low-temperature conditions. The oxidation process of neat NH3 and NH3 doped with NO (450, 800 ppm) was experimentally investigated in a Jet Stirred Flow Reactor at atmospheric pressure for the temperature range 900-1350 K. Results showed NO concentration is entirely controlled by DeNOx reactions in the temperature range 1100-1250 K, while NH3single bondNO interaction does not develop through a sensitizing NO effect, for these operating conditions. A detailed kinetic model was developed by systematically updating rate constants of controlling reactions and declaring new reactions for N2H2 isomers (cis and trans). The proposed mechanism well captures target species as NO and H2 profiles. For NH3single bondNO mixtures, NO profiles were properly reproduced through updated DeNOx chemistry, while NH2 recombination reactions were found to be essential for predicting the formation of H2. The role of ammonia as a third-body species is implemented in the updated mechanism, with remarkable effects on species predictions. For neat NH3 mixture, the reaction H+O2(+M)=HO2(+M) was crucial to predict NO formation via the reaction NH2+HO2double bondH2NO+OH.}, language = {en} } @misc{KurapatiBorgSeideletal., author = {Kurapati, Vinaykumar Reddy and Borg, Anders and Seidel, Lars and Mauß, Fabian}, title = {Fast CFD Diesel engine modelling using the 1-Dimentional SprayLet approach}, series = {SAE Technical Paper}, journal = {SAE Technical Paper}, number = {2024-01-2684}, issn = {0148-7191}, abstract = {In the SAE article 2023-24-0083: SprayLet: One-dimensional interactive cross-sectionally averaged spray model, we formulatet a one-dimensional Spray model in interaction with the surrounding gas phase. We could demonstrate, that the model predicted liquid and gaseous penetration length in good aggreement with ECN spray experiments. In this paper we use this model in engine CFD (CONVERGE CFD) and demonstrate a strong reduction in CPU time (50\%). We can show a strong decrease in grid dependency, which allows a further reduction of CPU time (90\%). We will present engine CFD simulations, comparing detailed spray with SpayLet simulations. This includes pressure traces, heat release, and emissions.}, language = {en} } @misc{FrankenSeidelGonzalezMestreetal., author = {Franken, Tim and Seidel, Lars and Gonzalez Mestre, Laura Catalina and Shrestha, Krishna Prasad and Matrisciano, Andrea and Mauss, Fabian}, title = {Assessment of Auto-Ignition Tendency of Gasoline, Methanol, Toluene and Hydrogen Fuel Blends in Spark Ignition Engines}, series = {THIESEL 2020 Conference on Thermo-and Fluid Dynamic Processes in Direct Injection Engines}, journal = {THIESEL 2020 Conference on Thermo-and Fluid Dynamic Processes in Direct Injection Engines}, pages = {23}, abstract = {State of the art spark ignited gasoline engines achieve thermal efficiencies above 46 \% e.g. due to friction optimized crank trains, high in-cylinder tumble flow and direct fuel injection. Further improvements of thermal efficiency are expected from lean combustion, higher compression ratio and new knock-resistant fuel blends. One of the limitations to these improvements are set by the autoignition in the end gas, which can develop to knocking combustion and severely damage the internal combustion engine. The auto-ignition is enhanced by high cylinder gas temperatures and reactive species in the end gas composition. Quasi-dimensional Stochastic Reactor Model simulations with detailed chemistry allow to consider the thermochemistry properties of surrogates and complex end gas compositions. Based on the detailed reaction scheme and surrogate model, an innovative tabulated chemistry approach is utilized to generate dual-fuel laminar flame speed and combustion chemistry look-up tables. This reduces the simulation duration to seconds per cycle, while the loss in accuracy compared to solving the chemistry "online" is marginal. The auto-ignition events predicted by the tabulated chemistry simulation are evaluated using the Detonation Diagram developed by Bradley and co-workers. This advanced methodology for quasi-dimensional models evaluates the resonance between the shock wave and reactionfront velocity from auto-ignition in the end gas and determines if it is a harmful developing detonation or normal deflagration. The aim of this work is to evaluate the auto-ignition characteristics of different fuel blends. The Stochastic Reactor Model with tabulated chemistry is applied to perform a numerical analysis of the autoignition of the fuel blends and operating conditions. Experimental measurements of a single cylinder research engine operated with RON95 E10 fuel are used to train and validate the simulation model. The RON95 E10 fuel is blended with Methanol, Hydrogen and Toluene. The knock tendency based on the evaluation of auto-ignition events of the different fuel blends are analysed for three operating points at 1500 rpm 15 bar IMEP, 2000 rpm 20 bar IMEP and 2500 rpm 15 bar IMEP with advanced spark timings.}, language = {en} } @misc{MalliotakisBanyonZhangetal., author = {Malliotakis, Zisis and Banyon, Colin and Zhang, Kuiwen and Wagnon, Scott W. and Rodriguez Henriquez, Jose Juan and Vourliotakis, George and Keramiotis, Christos and Founti, Maria and Mauß, Fabian and Pitz, William J. and Curran, Henry J.}, title = {Testing the validity of a mechanism describing the oxidation of binary n-heptane/toluene mixtures at engine operating conditions}, series = {Combustion and Flame}, volume = {199}, journal = {Combustion and Flame}, issn = {0010-2180}, doi = {10.1016/j.combustflame.2018.10.024}, pages = {241 -- 248}, abstract = {The aim of this work is to evaluate the influence of the n-heptane/toluene ratio on the reactivity of binary toluene reference fuels (TRFs), through a combined experimental and numerical work. Novel experimental ignition delay time (IDT) data of three binary TRFs of varying n-heptane/toluene ratios have been obtained in a high-pressure shock tube and in a rapid compression machine at conditions relevant to novel engine operation. Measurements have been performed at two pressures (10 and 30 bar), and at three fuel/air equivalence ratios (0.5, 1.0 and 2.0) for TRF mixtures of 50\%, 75\% and 90\% by volume toluene concentration, over the temperature range of 650-1450 K. It was found that, increasing the n-heptane content, led to an increase in reactivity and shorter measured IDTs. Reduced sensitivity to the equivalence ratio was observed at high temperatures, especially for high toluene content mixtures. A …}, language = {en} } @inproceedings{MaussSoyhanAmneusetal., author = {Mauß, Fabian and Soyhan, Hakan S. and Amn{\´e}us, Per and Sorusbay, Cem}, title = {"A Skeletal Kinetic Mechanism for the Oxidation of iso-Octane and n-Heptane under Engine Knock Conditions"}, doi = {10.4271/1999-01-3484.}, language = {en} } @article{MaussSoyhanSorusbay, author = {Mauß, Fabian and Soyhan, H. S. and Sorusbay, Cem}, title = {"Chemical Kinetic Modelling of Combustion in Internal Combustion Engines using Reduced Chemistry"}, doi = {10.1080/713712950}, language = {en} } @misc{MatriscianoFrankenGonzalesMestreetal., author = {Matrisciano, Andrea and Franken, Tim and Gonzales Mestre, Laura Catalina and Borg, Anders and Mauß, Fabian}, title = {Development of a Computationally Efficient Tabulated Chemistry Solver for Internal Combustion Engine Optimization Using Stochastic Reactor Models}, series = {Applied Sciences}, volume = {10}, journal = {Applied Sciences}, number = {24}, issn = {2076-3417}, doi = {10.3390/app10248979}, abstract = {The use of chemical kinetic mechanisms in computer aided engineering tools for internal combustion engine simulations is of high importance for studying and predicting pollutant formation of conventional and alternative fuels. However, usage of complex reaction schemes is accompanied by high computational cost in 0-D, 1-D and 3-D computational fluid dynamics frameworks. The present work aims to address this challenge and allow broader deployment of detailed chemistry-based simulations, such as in multi-objective engine optimization campaigns. A fast-running tabulated chemistry solver coupled to a 0-D probability density function-based approach for the modelling of compression and spark ignition engine combustion is proposed. A stochastic reactor engine model has been extended with a progress variable-based framework, allowing the use of pre-calculated auto-ignition tables instead of solving the chemical reactions on-the-fly. As a first validation step, the tabulated chemistry-based solver is assessed against the online chemistry solver under constant pressure reactor conditions. Secondly, performance and accuracy targets of the progress variable-based solver are verified using stochastic reactor models under compression and spark ignition engine conditions. Detailed multicomponent mechanisms comprising up to 475 species are employed in both the tabulated and online chemistry simulation campaigns. The proposed progress variable-based solver proved to be in good agreement with the detailed online chemistry one in terms of combustion performance as well as engine-out emission predictions (CO, CO2, NO and unburned hydrocarbons). Concerning computational performances, the newly proposed solver delivers remarkable speed-ups (up to four orders of magnitude) when compared to the online chemistry simulations. In turn, the new solver allows the stochastic reactor model to be computationally competitive with much lower order modeling approaches (i.e., Vibe-based models). It also makes the stochastic reactor model a feasible computer aided engineering framework of choice for multi-objective engine optimization campaigns.}, language = {en} } @misc{DongAulGregoireetal., author = {Dong, Shijun and Aul, Christopher and Gregoire, Claire and Cooper, Sean P. and Mathieu, Olivier and Petersen, Eric L. and Rodriguez, Jose and Mauß, Fabian and Wagnon, Scott W. and Kukkadapu, Goutham and Pitz, William J. and Curran, Henry J.}, title = {A comprehensive experimental and kinetic modeling study of 1-hexene}, series = {Combustion and Flame}, volume = {232}, journal = {Combustion and Flame}, issn = {1556-2921}, doi = {10.1016/j.combustflame.2021.111516}, abstract = {It is important to understand the low-temperature chemistry of 1-hexene as it is used as a representative alkene component in gasoline surrogate fuels. Ignition delay times (IDTs) of 1-hexene measured in rapid compression machines (RCMs) can be used to validate its low-temperature chemistry. However, volume history profiles are not available for published RCM IDT data. This has restricted the validation of the low-temperature chemistry of 1-hexene at engine-relevant conditions (i.e. at low temperatures and high pressures). Thus, new RCM IDT data with associated volume history profiles are needed. In this study, both an RCM and a high-pressure shock tube (ST) are employed to measure IDTs of 1-hexene at equivalence ratios of 0.5, 1.0 and 2.0 in 'air' and at pressures of 15 and 30 atm. A cool-flame (first stage) and total (second stage) ignition was observed in the RCM experiments. Moreover, carbon monoxide and water versus time histories produced during 1-hexene oxidation at highly diluted conditions were measured in a ST. A new detailed chemical kinetic model describing 1-hexene oxidation is proposed and validated using these new measured data together with various experimental data available in the literature. The kinetic model can predict well the auto-ignition behavior and oxidation processes of 1-hexene at various conditions. The rate constants and branching ratio for hydroxyl radical addition to the double bond of 1-hexene are particularly important and discussed based on the experimental and theoretically calculated results from previous studies as well as validation results from jet-stirred reactor (JSR) species profiles. Flux and sensitivity analyses are performed to determine the important reaction classes for 1-hexene oxidation and show that the reactions associated with hydroxy radical addition to the double bond contribute most to the low-temperature reactivity of 1-hexene. In the negative temperature coefficient (NTC) regime, the isomerization of hexenyl-peroxy radicals promotes fuel reactivity due to its associated chain branching pathways.}, language = {en} } @misc{RakhiShresthaGuentheretal., author = {Rakhi, Rakhi and Shrestha, Krishna Prasad and G{\"u}nther, Vivien and Mauß, Fabian}, title = {Thermodynamic analysis to develop a detailed surface reaction mechanism}, series = {Fuel Science - From Production to Propulsion, Aachen, Germany, May 2022}, journal = {Fuel Science - From Production to Propulsion, Aachen, Germany, May 2022}, pages = {2}, abstract = {The reduction of greenhouse gasses such as CO2 and CH4 is becoming necessary due to global environmental problems. The reforming of light hydrocarbons is a particularly efficient process for producing synthesis gas, H2 and CO, from greenhouse gasses [1]. The steam reforming of methane is the most important method to produce syngas in industry by using a nickel catalyst. Nickel-based catalysts are the conventional catalysts in industrial applications due to their fast turnover rates, good availability, and low costs, however, limited by their tendency towards coke formation. In this study, a detailed surface reaction mechanism is developed for steam reform-ing of methane over nickel and results are compared with the reference data.}, language = {en} } @misc{RakhiShresthaGuentheretal., author = {Rakhi, Rakhi and Shrestha, Krishna Prasad and G{\"u}nther, Vivien and Mauß, Fabian}, title = {Kinetically consistent detailed surface reaction mechanism for steam reforming of methane over nickel catalyst}, series = {Reaction Kinetics, Mechanisms and Catalysis}, volume = {135}, journal = {Reaction Kinetics, Mechanisms and Catalysis}, number = {6}, issn = {1878-5204}, doi = {10.1007/s11144-022-02314-7}, pages = {3059 -- 3083}, language = {en} } @misc{RakhiGuentherMauss, author = {Rakhi, Rakhi and G{\"u}nther, Vivien and Mauß, Fabian}, title = {A detailed surface reaction mechanism to investigate oxidation of methane over nickel catalyst}, series = {Proceedings in Applied Mathematics \& Mechanics : PAMM}, volume = {22}, journal = {Proceedings in Applied Mathematics \& Mechanics : PAMM}, number = {1}, issn = {1617-7061}, doi = {10.1002/pamm.202200055}, abstract = {We have developed a kinetically consistent detailed surface reaction mechanism for modeling the oxidation of methane over a nickel-based catalyst. A one-dimensional model, LOGEcat based on the single-channel 1D catalyst model, is used to perform the simulations. The original multi-step reaction mechanism is thermodynamically consistent and consists of 52 reactions. By thermodynamic consistency, we mean that the equilibrium is achieved with the support of the Arrhenius parameters and does not depend on the thermochemistry of the species involved in the considered reactions. The detailed mechanism developed in this investigation contains 26 reversible reactions. These reactions are obtained with the use of the thermochemistry of the species. The study focuses on ensuring kinetic consistency and this is done with the help of thermodynamic analysis by bringing the thermochemistry of the species in play in order to develop a surface reaction mechanism. The new mechanism can be used to understand the other processes, for example, steam- and dry-reforming of methane over nickel, however, the main focus of the paper is to check the performance of the detailed mechanism for catalytic partial oxidation of methane. The applicability of the mechanism is checked for various reactor conditions in terms of parameters such as temperature and pressure by comparing the results with the available reference data. The detailed mechanism developed in this study is able to accurately express oxidation of methane over the nickel catalyst for the considered reactor conditions.}, language = {en} } @misc{RakhiGiriGuentheretal., author = {Rakhi, Rakhi and Giri, Binod Raj and G{\"u}nther, Vivien and Mauss, Fabian}, title = {Investigation dry reforming of methane over nickel using a one-dimensional model}, series = {PAMM}, volume = {23}, journal = {PAMM}, number = {4}, doi = {10.1002/pamm.202300266}, pages = {8}, abstract = {In the field of catalysis, dry reforming, that is, methane reforming with CO2, is in the focus due to growing environmental concerns about oil depletion and global warming with a desire to produce synthesis gas. However, this process can lead to the formation of carbon, which can cause catalyst deactivation, especially at industrial conditions. Nevertheless, the key to develop a more coke-resistant catalyst is a better comprehension of the reforming process at a molecular level. Regardless of all the investigations available in literature, the detailed path for the conversion of methane to syngas and carbon remains a controversial issue. Another problem in setting up a reaction mechanism is the difficulty to define the thermodynamic data for intermediate surface species and this leads to the development of thermodynamic consistent surface reaction mechanisms in literature where the thermodynamic data are not used to calculate the rate coefficients of the reverse reactions. Rather the Arrhenius parameters for the forward as well as backward reactions are explicitly given in the reaction mechanism to establish thermodynamic equilibrium. In this investigation, a kinetically consistent detailed surface reaction mechanism is developed which consists of 26 reversible reactions with the help of a one-dimensional model, LOGEcat. Our previous work constructs the basis of the present investigation. Further, a detailed sensitivity analysis of reversible reactions and reaction pathways is performed to understand the mechanism better. The mechanism is validated for dry reforming of methane over nickel catalyst, however, it can also be used for other processes, such as, steam reforming and partial oxidation. The mechanism is tested by comparing the simulation results with the literature experiments and simulations in a wide range of temperature. The new developed kinetically consistent surface reaction mechanism is able to accurately express the dry reforming of methane over the nickel catalyst for complete range of temperature and also provide a useful insight into the key rate determining steps.}, language = {en} } @misc{RakhiGiriGuentheretal., author = {Rakhi, Rakhi and Giri, Binod Raj and G{\"u}nther, Vivien and Mauss, Fabian}, title = {Insight into the thermodynamic model for reforming of methane over nickel catalyst}, series = {Proceedings of the 64th International Conference of Scandinavian Simulation Society, SIMS 2023 V{\"a}ster{\aa}s, Sweden, September 25-28, 2023}, journal = {Proceedings of the 64th International Conference of Scandinavian Simulation Society, SIMS 2023 V{\"a}ster{\aa}s, Sweden, September 25-28, 2023}, doi = {10.3384/ecp200025}, pages = {192 -- 197}, abstract = {The reforming of light hydrocarbons to produce synthesis gas, H2 and CO, is an important intermediate for manufacturing valuable basic chemicals and synthesis fuels. In order to understand these reforming processes better, elementary step reaction mechanisms are developed. In the available literature, the surface reaction mechanisms are usually achieved with the help of reaction kinetic parameters without using the thermochemistry of the species referred to kinetic models due to the unavailability of the thermochemistry of the intermediate species involved in the multi-step reaction mechanism. In this work, investigations are made to obtain the thermochemistry of the intermediate species to establish thermodynamic equilibrium in order to develop a thermodynamic model for steam reforming of methane over nickel. The thermochemistry of the surface bound species is taken from different sources available in the literature and after that a detailed sensitivity analysis is performed to match the results with experiments. The simulation set up is adapted from the literature experiments given in [1]. The results produced with the one-dimensional tool using the thermodynamic model developed in the present investigation consisting of 21 reversible reactions are compared with the kinetic scheme with 42 irreversible reactions from reference simulation along with their experimental results. Both the models show some major differences in the reaction pathways which provides a useful insight into the key rate determining steps and needs further investigations.}, language = {en} } @misc{RakhiGuentherRichteretal., author = {Rakhi, Rakhi and G{\"u}nther, Vivien and Richter, Jana and Mauß, Fabian}, title = {Steam reforming of methane over nickel catalyst using a one-dimensional model}, series = {International Journal of Environmental Sciences}, volume = {5}, journal = {International Journal of Environmental Sciences}, number = {1}, issn = {2519-5549}, doi = {10.47604/ijes.1520}, pages = {1 -- 32}, abstract = {Steam reforming of hydrocarbons is a well established chemical process which provides synthesis gas (H2 and CO). These synthesis products can hence be converted to numerous valuable basic chemicals. For the industrial application of steam reforming, a detailed understanding of the process is a prerequisite. Models that capture the detailed homogeneous and heterogeneous reaction kinetics and the comprehensive transport processes as well as their interaction have the potential to optimize the catalytic process without expensive experimental campaigns. In this paper, a detailed investigation has been done using a multi-step reaction mechanism for modeling steam reforming of methane over nickel-based catalyst using a one-dimensional (1D) model, LOGEcat [1]. The model is applicable to the simulation of all standard after-treatment catalytic processes of combustion exhaust gas along with other chemical processes involving heterogeneous catalysis, such as, the Sabatier process [27]. It is a 1D tool, thus is computationally cost effective and is based on a series of perfectly stirred reactors (PSR). The model is used to perform the simulations for various reactor conditions in terms of temperature, pressure, flow rates and steam-to-carbon (S/C) ratio. Several chemical reaction terms, such as, selectivity, yield, conversion, and mole fraction have been shown with respect to the varied parameters and the results are compared with 2D simulations and experimental reference data. We report a very good agreement of the various profiles produced with 1D model as compared to the reference data. Note that the main aim of this study is to check how far the 1D model can capture the basic chemistry for modeling steam reforming of methane over nickel-based catalysts. It is interesting to note that the cost effective reduced order model is capable to capture the physics and chemistry involved with a multi-step reaction mechanism showing the predictive capability of the model. This study forms the basis for further analysis towards the thermochemistry of the species to develop a kinetically consistent reaction mechanism.}, language = {en} } @misc{RakhiGuentherMauss, author = {Rakhi, Rakhi and G{\"u}nther, Vivien and Mauß, Fabian}, title = {Insights into dry reforming of methane over nickel catalyst using a thermodynamic model}, series = {Reaction Kinetics, Mechanisms and Catalysis}, journal = {Reaction Kinetics, Mechanisms and Catalysis}, issn = {1878-5204}, doi = {10.1007/s11144-023-02426-8}, pages = {14}, abstract = {A thermodynamic model is developed using a one-dimensional model, LOGEcat to understand the dry reforming of methane over nickel-based catalysts. To do so, we have extended our previously developed mechanism (Rakhi and Shrestha in React Kinet, Mech Catal 135:3059-3083, 2022) which contains 21 reversible reactions by adding 5 more reversible reactions and updating the thermochemistry of one intermediate species. The adjusted mechanism contains 26 reversible reactions obtained with the help of thermodynamic analysis. This study focuses on using the thermodynamic model for dry reforming of methane and insights into the reaction pathways and sensitivity analysis for the kinetically consistent surface reaction mechanism. The applicability of the mechanism is examined for reactor conditions in terms of parameters such as temperature by comparing the results with the available reference data. The mechanism is able to accurately express the reforming conditions of methane over the nickel catalyst for complete range of temperature and also provide useful insights into the reaction pathways established with the thermodynamic model.}, language = {en} }