车用直喷式柴油机多维燃烧模拟计算与分析

应用AVL公司的FIRE软件,对一台4100型直喷式柴油机的喷雾燃烧过程进行了多维模拟计算,得到了缸内流场变化,温度变化及排放物浓度分布以及示功图等重要信息。通过对柴油机缸内喷雾流场及排放污染物浓度分布情况进行详细分析,得出了油雾在燃烧室的运动情况,在理论上说明了燃烧室底部凸起可以促进缸内油气混合,以及NO和Soot的主要生成区域及生成历程,使在实验中难以观测的现象在模拟计算中得以再现,为进一步改善喷雾状况,提高燃烧过程降低有害排放提供了有力的参考依据。

Multi-dimensional Simulation and Analysis of Combustion Process in DI Diesel

The fire software developed by AVL is adopted to simulate spray and combustion process of a 4100 DI diesel engine.With numerical simulation,some important information in the cylinder which cannot get in the experiment is gotten such as velocity and temperature fields and emission distribution.Furthermore,the characteristic of flow field and the emission distribution are analyzed in detail in this paper.By numerical simulation,there are some conclusions which are the effective basis to improve the spray condition and improve the combustion process and reduce the exhaust gas emission.One is that the prostration in the combustion chamber could improve the mix process of fuel and air;the other is that the main fields of NO and Soot and the growing process are given in the simulation.