@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 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{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{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{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{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{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} } @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{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} } @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} } @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} } @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} } @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} } @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} } @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{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{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{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{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} } @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} }