某柴油机缸盖CAE分析及优化设计

Cylinder Head CAE Analysis and Design Optimization of a Diesel Engine

缸盖在工作环境中受到高温、高压的综合影响,其性能直接决定着柴油机的寿命。为改善缸内的燃烧性能,将单喷油器布置的缸盖变更为多个喷油器布置的缸盖。以布置多个喷油器的缸盖为研究对象,结合柴油机缸内燃烧边界和冷却边界,并考虑缸盖螺栓预紧力、缸内爆压等机械载荷进行热机耦合分析。结果表明,高应力区域集中在缸盖火焰面,最大达到580 MPa。在应力场基础上对缸盖进行疲劳评估,结构优化后的疲劳结果满足设计要求。

The cylinder head is affected by high temperature and high pressure in the working environment,and its performance directly determines the use life of the diesel engine.In order to improve the combustion performance in the cylinder,the cylinder head with a single injector is changed to a cylinder head with multiple injectors.This paper takes the cylinder head with multi-injector arrangement as the research object,combines the combustion boundary and cooling boundary in the diesel engine cylinder,and considers the mechanical loads such as cylinder head bolt pre-load and cylinder explosion pressure to conduct a thermo-mechanical coupling analysis.The results show that the high stress area is concentrated on the flame deck,with a maximum of 580 MPa.Based on the stress field,the cylinder head is evaluated for fatigue,and the fatigue results after structural optimization meet the design requirements.