Cylinder head thermo-mechanical coupling simulation on two-phase flow boiling heat transfer system

From the theory and calculation methods of vapor-liquid two-phase flow boiling heat transfer, the fluid-solid coupling heat transfer system comprising a cylinder head and a cooling water jacket for a diesel engine was solved. The distribution of the cylinder head temperature was obtained and validated by the experimental data. The cylinder head temperature field simulation result was added to the thermo-mechanical coupling system which consists of the cylinder head, bolts and cylinder block, and the distribution of the cylinder head thermo-mechanical coupling stress field was achieved. Using the experiment design method, the cylinder head flame-face maximum equivalent stress of some large stress areas were analyzed with the cooling water inlet temperature and velocity as input parameters. The results show that considering the vapor-liquid two-phase flow boiling heat transfer can effectively reduce the maximum thermo-mechanical coupling stress of the cylinder head flame-face. The maximum thermo-mechanical coupling stress appears around the injector hole. In addition, the effects of cooling water inlet temperature on the cylinder head flame-face maximum equivalent stress of some large stress areas cannot be ignored.