Abstract:The influences of charge stratification on spark ignition (SI) engine combustion and NO emission were analyzed using a phenomenological model. The mixture in the cylinder was divided spherically into three parts: a central core with a stoichiometric air-fuel charge, a dilution region without any combustible charge, and a mixing region lying between the core and the dilution region. Three mixture stratification parameters such as the extent of dilution in the mixing region, the extent of combustible charge in the mixing region, and the gradient of stratification in the mixing region were investigated. The results indicate that the extent of combustible charge in the mixing region could reduce in-cylinder NO formation significantly, compared with the extent of dilution in the mixing region. As long as the degree of dilution in the mixing region is within the dilution limit of the combustible charge, the gradient of dilution has little effect on combustion and NO formation.
. Numerical simulation of charge stratifications
to improve combustion and NO formation of lean-burn SI engines[J]. Front. Energy, 2009, 3(3): 353-358.
Zhijun PENG , . Numerical simulation of charge stratifications
to improve combustion and NO formation of lean-burn SI engines. Front. Energy, 2009, 3(3): 353-358.
Germane G J, Wood C G, Hess C C. Lean combustion in spark-ignited internal combustionengines―a review. SAE paper 831694, 1983
Das A, Watson H C. Development of a naturalgas spark ignition engine for optimum performance. Journal of Automobile Engineering, 1997, 211(5): 361―378 doi: 10.1243/0954407971526506
Goldwitz J A, Heywood J B. Combustion Optimization ina Hydrogen-Enhanced Lean-Burn SI Engine. SAE paper 2005-01-0251, 2005
Su H, Vikhansky A, Mosbach S, et al. A computational study of an HCCI engine withdirect injection during gas exchange. Combustionand Flame, 2006, 147(2): 118―132 doi: 10.1016/j.combustflame.2006.07.005
Peng Z, Zhao H, Ma T, et al. Characteristics of homogeneous charge compressionignition (HCCI) combustion and emissions of n-heptane. Combustion Science and Technology, 2005, 177(11): 2113―2150 doi: 10.1080/00102200500240588
Swamy K R, Harne V, Gunjegaonkar D S, et al. Study and Development of Lean-burnSystems on Small 4-Stroke Gasoline Engine. SAE paper 2001-01-1801, 2001
D’Errico G, Onorati A. An Integrated SimulationModel for the Prediction of GDI Engine cylinder emissions and exhaustafter-treatment and outer annular air region without fuel, and ansystem performance. SAE paper 2004-01-0043, 2004
Aditya M, Han J-S, Lu P-H, et al. Modeling Dynamic Behavior of Diesel Fuel InjectionSystems. SAE paper 2004-01-0536, 2004
Zhao H, Calnan P, Ladommatos N, et al. Development of an Engine Simulation Programand Its Application to Stratified Charge SI Engines. International Journal of Vehicle Design, 1999, 22(3,4): 159―194
Beretta G P, Rashidi M, Keck J C. Turbulent flame propagation and combustion in spark ignitionengines. Combustion and Flame, 1983, 52: 217―245 doi: 10.1016/0010-2180(83)90135-9
Olikara C, Borman B. A Computer Program for CalculationProperties of Equilibrium Combustion Products with Some Applicationsto IC Engines. SAE paper 750468, 1975
Cox R A, Cole J A. Chemical aspects of the autoignitionof hydrocarbon---air mixtures. Combustionand Flame, 1985, 60(2): 109―123 doi: 10.1016/0010-2180(85)90001-X
Halstead M, Kirsch L, Prothero A, et al. A mathematical model for hydrocarbon autoignitionat high pressures. Proc R Soc Lond A, 1975, 346: 515―538 doi: 10.1098/rspa.1975.0189
Quader A A. Why intake charge dilution decreases nitric oxide emission from sparkignition engines. SAE paper 710009, 1971
Quader A A. Effects of spark location and combustion duration on nitric oxideand hydro-carbon emissions. SAE paper 730153, 1973