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Accurate and Dynamic Accounting of Fuel Composition in Flame Propagation During Engine Simulations
Technical Paper
2016-01-0597
ISSN: 0148-7191, e-ISSN: 2688-3627
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English
Abstract
A methodology has been implemented to calculate local turbulent flame speeds for spark ignition engines accurately and on-the-fly in 3-D CFD modeling. The approach dynamically captures fuel effects, based on detailed chemistry calculations of laminar flame speeds. Accurately modeling flame propagation is critical to predicting heat release rates and emissions. Fuels used in spark ignition engines are increasingly complex, which necessitates the use of multi-component fuels or fuel surrogates for predictive simulation. Flame speeds of the individual components in these multi-component fuels may vary substantially, making it difficult to define flame speed values, especially for stratified mixtures. In addition to fuel effects, a wide range of local conditions of temperature, pressure, equivalence ratio and EGR are expected in spark ignition engines. Flame speed variations with fuel composition and local operating conditions need to be captured well to predict combustion phasing and heat release rates.
To capture fuel effects, flame speeds of 44 potential surrogate fuel components have been considered. These 44 fuels included components representing the chemical families n-alkanes, isoalkanes, cyclo-alkanes, alkenes, cyclo-alkene, iso-alkene, aromatics, ethers, cyclo-ethers, alcohols and methyl esters. Laminar flame speeds, which are used to calculate turbulent flame speeds in ANSYS Forte CFD, were generated as tables using the ANSYS Chemkin 1-dimensional Flame-speed Calculator for each of the 44 surrogate fuels. Using pure-fuel flame speeds and local fuel composition in the CFD simulation, multi-component-fuel flame speeds were calculated on-the-fly using non-linear blending of the single-component values. The accuracy of this non-linear blending approach was verified using Chemkin simulations covering the range of operating conditions of interest. For each pure fuel flame speed table, about 1500 conditions of temperatures, pressures, equivalence ratios and EGR were evaluated, to cover most engine conditions.
These ANSYS Chemkin simulations used well validated chemistry from the Model Fuels Library, where a single master mechanism includes 9179 species and 38505 reactions, representing combustion and pyrolysis reactions of all 44 fuel components. From this super-set, targeted mechanism reduction was performed to assemble a skeletal but still very detailed mechanism for each fuel. Care was taken to verify the appropriate grid-resolution for the flame-speed calculations and to establish a method to address very high temperatures and pressures, where auto-ignition competes with flame propagation. The approach presented provides (a) simplicity in the user input required for the CFD simulation (only fuel composition is required), (b) a high degree of accuracy afforded by the Chemkingenerated flame-speed library for an extensive range of fuel components and (c) the automation of the blending without compute performance penalty. Example engine simulations show the impact on spark-ignited flame propagation, relative to conventional approaches.
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Citation
Puduppakkam, K., Wang, C., Hodgson, D., Naik, C. et al., "Accurate and Dynamic Accounting of Fuel Composition in Flame Propagation During Engine Simulations," SAE Technical Paper 2016-01-0597, 2016, https://doi.org/10.4271/2016-01-0597.Also In
References
- Metghalchi , M. and Keck , J.C. Burning velocities of mixtures of air with methanol, isooctane, and indolene at high pressure and temperature Combustion and Flame 1982 48 191 210
- Gülder , Ö. Correlations of Laminar Combustion Data for Alternative S.I. Engine Fuels SAE Technical Paper 841000 1984 10.4271/841000
- CHEMKIN-PRO 15141 2015 Reaction Design San Diego
- The Model Fuels Consortium 2008 www.modelfuelsconsortium.com
- Model Fuel Library 2015 ANSYS Reaction Design San Diego
- Puduppakkam , K. , Naik , C. , Wang , C. , and Meeks , E. Validation Studies of a Detailed Kinetics Mechanism for Diesel and Gasoline Surrogate Fuels SAE Technical Paper 2010-01-0545 2010 10.4271/2010-01-0545
- Pitz , W. , Cernansky , N. , Dryer , F. , Egolfopoulos , F. et al. Development of an Experimental Database and Chemical Kinetic Models for Surrogate Gasoline Fuels SAE Technical Paper 2007-01-0175 2007 10.4271/2007-01-0175
- Farrell , J.T. , Johnston , R.J. , and Androulakis , I.P. Molecular structure effects on laminar burning velocities at elevated temperature and pressure 2004
- Farrell , J. , Cernansky , N. , Dryer , F. , Law , C. et al. Development of an Experimental Database and Kinetic Models for Surrogate Diesel Fuels SAE Technical Paper 2007-01-0201 2007 10.4271/2007-01-0201
- Colket , M. , Edwards , T. , Williams , S. , Cernansky , N.P. et al. Development of an Experimental Database and Kinetic Models for Surrogate Jet Fuels 45th AIAA Aerospace Sciences Meeting 2007 AIAA Reno, NV
- Naik , C. , Puduppakkam , K. , Wang , C. , Kottalam , J. et al. Applying Detailed Kinetics to Realistic Engine Simulation: the Surrogate Blend Optimizer and Mechanism Reduction Strategies SAE Int. J. Engines 3 1 241 259 2010 10.4271/2010-01-0541
- Reaction Design ANSYS Forte CFD 40145 2015 Reaction Design San Diego
- Naik , C. , Puduppakkam , K. , and Meeks , E. Modeling the Detailed Chemical Kinetics of NOx Sensitization for the Oxidation of a Model fuel for Gasoline SAE Int. J. Fuels Lubr. 3 1 556 566 2010 10.4271/2010-01-1084
- Naik , C.V. , Puduppakkam , K.V. , and Meeks , E. An improved core reaction mechanism for C0-C4 unsaturated fuels and C0-C4 fuel blends Proceedings of ASME Turbo Expo, GT2012-68722 2012
- Naik , C.V. , Puduppakkam , K.V. , and Meeks , E. An Improved Core Reaction Mechanism for Saturated C0-C4 Fuels Journal of Engineering for Gas Turbines and Power 2011 134 2
- Dowdy , D.R. , Smith , D.B. , Taylor , S.C. , and Williams , A. The use of expanding spherical flames to determine burning velocities and stretch effects in hydrogen/air mixtures Twenty-Third Symposium (International) on Combustion 1990 23 325 332
- Aung , K.T. , Hassan , M.I. , and Faeth , G.M. Flame stretch interactions of laminar premixed hydrogen/air flames at normal temperature and pressure Combustion and Flame 1997 109 1 24
- Tse , S.D. , Zhu , D.L. , and Law , C.K. Morphology and burning rates of expanding spherical flames in H2/O2/inert mixtures up to 60 atmospheres Proceedings of the Combustion Institute 2000 28 1793 1800
- Vagelopoulos , C.M. and Egolfopoulos , F.N. Laminar Flame Speeds and Extinction strain rates of Mixtures of Carbon Monoxide with Hydrogen, Methane and Air Twenty-Fifth Symposium (International) on Combustion 1994 1317 1323
- Verhelst , S. , Woolley , R. , Lawes , M. , and Sierens , R. Laminar and unstable burning velocities and Markstein lengths of hydrogen-air mixtures at engine-like conditions Proceedings of the Combustion Institute 2005 30 209 216
- Burke , M.P. , Chaos , M. , Dryer , F.L. , and Ju , Y. Negative pressure dependence of mass burning rates of H2/CO/O2/diluent flames at low flame temperatures Combustion and Flame 2010 157 618 631
- McLean , I.C. , Smith , D.B. , and Taylor , S.C. The use of carbon monoxide/hydrogen burning velocities to examine the rate of the CO+OH reaction Twenty-Fifth Symposium (International) on Combustion 1994 749 757
- Sun , H. , Yang , S.I. , Jomaas , G. , and Law , C.K. High-pressure laminar flame speeds and kinetic modeling of carbon monoxide/hydrogen combustion Proceedings of the Combustion Institute 2007 31 439 446
- Vagelopoulos , C.M. , Egolfopoulos , F.N. , and Law , C.K. Further Considerations on the Determination of Laminar Flame Speeds with the Counterflow Twin-Flame Technique Twenty-Fifth Symposium (International) on Combustion 1994 The Combustion Institute
- Kochar , Y. , Seitzman , J. , Lieuwen , T. , Metcalfe , W. et al. Laminar Flame Speed Measurements and Modeling of Alkane Blends at Elevated Pressures with Various Diluents Proceedings of ASME Turbo Expo, GT2011 2011
- Egolfopoulos , F.N. , Du , D.X. , and Law , C.K. A Study on Ethanol Oxidation Kinetics in Laminar Premixed Flames, Flow Reactors, and Shock Tubes Twenty-Fourth Symposium (International) on Combustion 1992 833 841
- Davis , S.G. , Law , C.K. , and Wang , H. Propene Pyrolysis and Oxidation Kinetics in a Flow Reactor and Laminar Flames Comb. Flame 1999 119 375 399
- Davis , S.G. , Law , C.K. , and Wang , H. An experimental and kinetic modeling study of propyne oxidation Twenty-Seventh Symposium (International) on Combustion 1998 305 312
- Davis , S.G. and Law , C.K. Determination of fuel structure effects on laminar flame speeds of C1 to C8 hydrocarbons Combustion Science and Technology 1998 140 427 449
- Veloo , P.S. , Wang , Y.L. , Egolfopoulos , F.N. , and Westbrook , C.K. A comparative experimental and computational study of methanol, ethanol, and n-butanol flames Combustion and Flame 2010 157 10 1989 2004
- Davis , S.G. and Law , C.K. Laminar flame speeds and oxidation kinetics of iso-octane-air and n-heptane-air flames 27th Symposium (International) on Combustion 1998
- Kumar , K. , Freeh , J.E. , Sung , C.J. , and Huang , Y. Laminar flame speeds of preheated iso-octane/O 2 /N 2 and nheptane/O 2 /N 2 mixtures Journal of Propulsion and Power 2007 23 2 430
- Huang , Y. , Sung , C.J. , and Eng , J.A. Laminar flame speeds of primary reference fuels and reformer gas mixtures Combustion and Flame 2004 139 239 251
- Bradley , D. , Hicks , R.A. , Lawes , M. , Sheppad , C.G.W. et al. The measurement of laminar burning velocities and Markstein numbers for iso-octane-air and iso-octane-nheptane-aire mixtures at elevated temperatures and pressues in an explosion bomb Combustion and Flame 1998 115 126 144
- Ji , C. and Egolfopoulos , F.N. Flame propagation of mixtures of air with binary liquid fuel mixtures Proceedings of the Combustion Institute 2011 33 955 961
- Mehl , M. , Herbinet , O. , Dirrenberger , P. , Bounaceur , R. et al. Experimental and modeling study of burning velocities for alkyl aromatic components relevant to diesel fuels Proceedings of the Combustion Institute 2015 35 341 348
- Hui , X. , Das , A.K. , Kumar , K. , Sung , C.-J. et al. Laminar flame speeds and extinction stretch rates of selected aromatic hydrocarbons Fuel 2012 97 695 702
- Kumar , K. and Sung , C.J. Laminar flame speeds and extinction limits of preheated n-decane/O 2 /N 2 and ndodecane/O 2 /N 2 mixtures Combustion and Flame 2007 151 1-2 209 224
- Ji , C. and Egolfopoulos , F.N. Flame propagation of mixtures of air with binary liquid fuel mixtures Proceedings of the Combustion Institute 2011 33 955 961
- Naik , C. , Liang , L. , Puduppakkam , K. , and Meeks , E. Simulation and Analysis of In-Cylinder Soot Formation in a Gasoline Direct-Injection Engine Using a Detailed Reaction Mechanism SAE Technical Paper 2014-01-1135 2014 10.4271/2014-01-1135