【摘要】 将发动机多维CFD程序KIVA-3V与化学动力学程序CHEMKINⅢ相耦合,分析了汽油HCCI发动机燃烧特性及排放物的生成机理及演变规律.发动机以异辛烷为燃料,其化学反应采用了详细的动力学机理.结果表明,此计算模型所得到的缸内压力及放热率的变化趋势与实验基本吻合;由于缝隙区温度较低,因而其成了汽油HCCI发动机HC排放的主要来源,而CO排放的主要来源则是边界层区;由于气缸中心区域温度较高,而NO的生成与温度呈指数关系,因此该区域为汽油HCCI发动机NO排放的主要来源.更多还原

【Abstract】 By coupling the engine CFD package(KIVA-3V) with the chemical kinetics package(CHEMKIN Ⅲ),the formation and evolution of the emissions of the gasoline HCCI engine were simulated.Iso-octane was used as fuel and the detailed reaction mechanisms were adopted.The numerical simulation results show that the pressure and heat release obtained by this computational model are almost the same as the experimental results.At the same time,HC emissions is mainly from the crevice zone due to its low temperature,CO emission chiefly from the boundary zone,and NO emission mostly from the core zone in the cylinder owing to its high temperature.更多还原