通过模拟整车在上下坡过程中发动机工作状况，建立了冷却水套非稳态工作环境，利用CFX流体分析软件对非稳态工况下的冷却水套流动传热状况进行仿真分析，得到了冷却液流场和温度场，通过流固耦合分析得出了发动机缸体缸盖热负荷的分布情况。对发动机进行了实际的变工况试验验证，证明了仿真分析的正确性，验证了冷热冲击试验可以为冷却水套换热分析提供准确的工况环境。

The unsteady working environment of water jacket was established by simulating the engine working state during the process of downhill and uphill. The flow and temperature fields of cooling water were acquired by analyzing the water flow and heat transfer under unsteady conditions with CFX software. The heat distributions of engine cylinder and cylinder head were further determined according to the fluidsolid coupling analysis. The test verification of variable conditions was finally conducted. The results show that the simulation method is feasible. It is also proved that the cold and thermal shock test can provide a necessary environment for the heat transfer analysis of water jacket.