Effects of Charge Density and Temperature on Combustion and Emissions in a Diesel Engine
Engine experiments and CFD modeling studies have been carried out and shown that high density-low temperature combustion (HD-LTC) has the potential of realizing high thermal efficiency and very low engine-out emissions at engine’s high and full loads. Parametric studies were conducted to explore the mechanism of formation of pollutants in high charge density in this paper. It was found that high charge density was normally favorable to spray atomization, evaporation and fuel/air mixing throughout the entire combustion process, but there was a turning value of charge density, above which the promotion on mixing rate was reduced. The conversion of CO to CO2 was accelerated and CO emission was decreased with increasing charge density, which led to high indicated thermal efficiency. The histories of normalized mass fractions for different intervals of fuel/air equivalence ratio were derived by using a CFD model. It was found that the over-mixing mixture caused by high charge density led to slight increase in UHC emissions.
Wanhua Su Yingying Lu Wenbin Yu Yiqiang Pei Feiyang Zhao
State Key Laboratory of Engines, Tianjin University
国际会议
天津
英文
1-10
2009-08-19（万方平台首次上网日期，不代表论文的发表时间）