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