基于CFD分析的二冲程发动机直喷燃烧室方案设计

采用三维实体建模软件UG对此二冲程发动机的燃烧室进行直喷化设计，并利用三维CFD仿真软件Fluent对直喷燃烧室的缸内流场进行CFD仿真与分析.分析结果显示：当燃烧室高度从32mm降为24mm，以及活塞顶面与缸盖底面距离从7mm降为3mm时，压缩过程中的反滚流结构消失，扫气效率从87%升高到91%.模拟结果为进一步优化燃烧室结构提供了较好依据.

Design of combustion chamber program of two-stroke direct injection spark ignition engine based on the CFD

The combustion chamber of the two-stroke engine was modified to a direct-injection combustion chamber by using 3-D entity modeling software UG, then 3-D CFD software Fluent was used to simulate and analyze the in-cylinder fluid structure. The results show that, when the height of combustion chamber is reduced to 24mm from 32mm, and the distance from the top of piston to the bottom of cylinder head is reduced to 3mm from 7mm, the roll back flow structure in the process of compression disappears, and the scavenging efficiency increases from 87% to 91%. The simulation results provide a good basis for further structure optimization of combustion chamber.