Atkinson循环发动机紧凑型燃烧系统研究

基于Atkinson理论循环建立混合动力汽油机的性能仿真模型,确定出合适的压缩比与配气正时。分别采用增加活塞顶面凸起高度(上凸型燃烧室)和减小缸盖上燃烧室高度的方式来满足Atkinson循环汽油机对压缩比的要求。同时为适应紧凑结构减小气门升程、直径(紧凑型燃烧室)。通过三维CFD计算分析,比较了两种燃烧室缸内燃烧及流动特性,发现紧凑型燃烧室能够在火核形成及扩散时期在缸内产生更高的湍动能,有利于加快火焰传播,使燃烧持续期缩短9.8%~24.4%,可显著提高燃油经济性。在混合动力用Atkinson循环发动机开发中使用紧凑型燃烧室,具有重要的应用价值。

Research on Compact Combustion System for Atkinson Cycle Engine

Based on Atkinson theoretical cycle ,the performance simulation model of hybrid gasoline engine was built and the compression ratio and valve timing were determined .The requirements of compression ratio for Atkinson gasoline engine has been met with increasing the bumped height of piston top surface (convex combustion chamber) and decreasing the height of cylinder head combustion chamber (compact combustion chamber) .With three‐dimensional CFD analysis ,the combustion and flow characteristics of the two types of combustion chambers were compared .The results show that the compact combustion chamber can produce the higher turbulent kinetic energy in the period of flame kernel formation and diffusion ,accelerate the flame propagation and shorten the combustion duration by 9 .8% ~24 .4% with improved fuel economy .The application of compact combustion chamber in the development of hybrid Atkinson cycle engine is of great value .