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Simulations of Fuel/Air Mixing, Combustion, and Pollutant Formation in a Direct Injection Gasoline Engine
Technical Paper
2002-01-0835
ISSN: 0148-7191, e-ISSN: 2688-3627
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English
Abstract
Simulations of a Direct Injection Spark Ignition (DISI) engine have been performed for both early injection with homogeneous charge combustion and for late injection with stratified charge combustion. The purpose has been to study flow characteristics, fuel/air mixing, combustion, and NOx and soot formation. Focus is put on the combustion modeling.
Two different full load cases with early injection are simulated, 2000 rpm and 6000 rpm. One load point with late injection is simulated, 2000 rpm and 2.8 bar net MEP. Three different injection timings are simulated at the low load point: 77, 82, and 87 CAD bTDC.
The spray simulations are tuned to match measured spray penetrations and droplet size distributions at both atmospheric and elevated pressure. Boundary conditions for the engine simulations are taken from 1-D gas exchange simulations that are tuned to match engine tests. The engine simulations start 380 CAD's before TDC and include the closing of the exhaust valves, the whole intake stroke, injection, combustion, and expansion to 113 CAD aTDC. Combustion is simulated using a turbulent Flame Speed Closure (FSC) model. The model takes into account the effects of local mixture composition, turbulence, temperature, and pressure and predicts reasonably well the heat release rate in all the cases without tuning of any constants. From this it is concluded that it is well suited for SI engine combustion predictions. The model also handles the diffusion controlled post oxidation of the unburned fuel from overly rich regions.
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Wallesten, J., Lipatnikov, A., and Chomiak, J., "Simulations of Fuel/Air Mixing, Combustion, and Pollutant Formation in a Direct Injection Gasoline Engine," SAE Technical Paper 2002-01-0835, 2002, https://doi.org/10.4271/2002-01-0835.Also In
References
- Fan L. Reitz R.D. “Spray and Combustion Modeling in Gasoline Direct-Injection Engines” Atomization and Sprays 10 219 249 2000
- Abraham J. Bracco F.V. Reitz R.D. “Comparisons of Computed and Measured Premixed Charge Engine Combustion” Combustion and Flame 60 309 322 1985
- Ranasinghe J. Cant S. “A Turbulent Combustion Model for a Stratified Charged, Spark Ignited Internal Combustion Engine” SAE Paper 2000-01-0275 2000
- Baritaud T.A. Duclos J.M. Fusco A. “Modeling Turbulent Combustion and Pollutant Formation in Stratified Charge SI Engines” Twenty-Sixth Symposium (Internationsl) on Combustion 2627 2635 1996
- Lipatnikov, A.N. Chomiak, J. “Turbulent Flame Speed and Thickness: Phenomenology, evaluation, and application in multi-dimensional simulations” Progress in Energy and Combustion Science 28 1 73 2002
- Zimont, V.L. “To Computations of Turbulent Combustion of Partially Premixed Gases” Chemical Physics of Combustion and Explosion Processes. Combustion of Multi-phase and Gas Systems OIKhF Chernogolovka 77 80 1977
- Zimont, V.L. Combustion, Explosions, and Shock Waves 15 305 1997
- Lipatnikov, A.N. Chomiak, J. “A Simple Model of Unsteady Turbulent Flame Propagation” SAE Paper No. 972993 1997
- Wallesten J Lipanikov A.N. Nisbet J. “Turbulent Flame Speed Closure Model: Further Development and Implementation for 3-D Simulation of Combustion in SI Engine” SAE Paper 982613 1998
- Lipatnikov. A. Wallesten, J. Nisbet, J. “Testing of a Model for Multi-Dimensional Computations of Turbulent Combustion in Spark Ignition Engines” The Fourth International Symposium COMODIA 98 1998
- FIRE Manual, Version 7.2b AVL LIST GmbH Graz 2000
- Hörnquist N. “Spraymodellering i CFD-koden FIRETM” Diploma work, Dept. of Construction and Production Technology University of Linköping Linköping 1999
- Naber, J.D. Reitz, R.D. “Modeling Engine Spray/Wall Impingement” SAE 880107 1988
- Wallesten, J. Golovitchev. V. “Calculations of Laminar Flame Speeds for Iso-octane Mixtures Including Effects of Pressure, Temperature, and Exhaust Gas Dilution”
- Gülder, Ö.L. “Laminar Burning Velocities of Methanol, Ethanol and Isooctane-Air Mixtures” Nineteenth Symposium (International) on Combustion/The Combustion Institute 1982 275 281
- Metghalchi, M. Keck, J.C. “Burning Velocities of Mixtures of Air With Methanol, Iso-octane, and Indolene at High Pressure and Temperature” Combustion and Flame 48 191 210 1982
- Müller, U.C. Bollig, M. Peters, N. “Approximations for Burning Velocities and Markstein Numbers for Lean Hydrocarbon and Methanol Flames” Combustion and Flame 108 349 356 1997
- Davis, S.G. Law, C.K. “Determination of and Fuel Structure Effects on Laminar Flame Speeds of C 1 to C 8 Hydrocarbons” Combust. Sci. and Tech. 1998 140 427 449
- Bradley, D. Hicks, R.A. Lawes, M. Sheppard, C.G.W. Wooley, R. “The Measurement of Laminar Burning Velocities and Markstein Numbers for Iso-octane and Iso-octane-n-Heptane-Air Mixtures at Elevated Temperatures and Pressures in an Explosion Bomb” Combustion and Flame 115 126 144 1998
- Ra, Y. Cheng, W.K. “Laminar Flame Propagation Through a Step-Stratified Charge” COMODIA 2001