柴油机气缸盖热负荷仿真分析

以某6V110高强化柴油机为研究对象,建立单排冷却水套流场分析模型,确定冷却效果最差的一缸。考虑材料塑性因素,建立该气缸盖流固耦合和结构分析模型,研究热应力的分布特点。结果表明,该气缸盖火力面最大应力及塑性应变均出现在排气道与气门交汇处,排气门侧发生疲劳破坏的可能性较大,与试验结果相符。基于流固耦合计算模型,采用正交设计方法研究了影响气缸盖热负荷的因素,燃气温度和冷却水流量是影响热负荷的主要因素。

Simulation and Analysis of Thermal Load for Diesel Cylinder Head

Based on a 6V110 heavy-duty diesel engine,the flow field model of single-row cooling water jacket was built and cylinder head with the worst cooling effect was found.Considering the material plasticity,the fluid-solid coupling model and structural analysis model of head cylinder were established,and the distribution of thermal stress was researched.The results showed that the maximum stress and equivalent plastic strain of cylinder head fire face were located in the intersection of exhaust manifold and valves.Accordingly,it was predicted that the thermal fatigue failure probably happened in the exhaust side,which was consistent with the experimental result.Based on the fluid-solid calculation model,the influencing factors of thermal load were studied with the orthogonal experiment method,and it was concluded that the gas temperature and coolant flow rate were the main factors.