Simulation study on cylinder head temperature field with consideration of two-phase flow boiling heat transfer

Taking ANSYS Workbench as simulation platform and considering effects of cooling water flow and boiling heat transfer, a mesh model for fluid-solid coupled heat transfer system consisting of cylinder head and cooling water jacket was built up based on the computational fluid dynamics module CFX. Two methods, the gas-liquid two-phase flow boiling heat transfer and single-phase flow (without considering boiling heat transfer) were used to resolve together the fluid-solid coupled heat transfer system consisting of cylinder head and cooling water jacket, the cylinder head temperature field distribution under rated power condition was obtained. Results show that compared with the single-phase flow without considering boiling heat transfer, the highest temperatures in the head exhaust valve bridge zone and exhaust port side were effectively reduced using the two-phase flow boiling heat transfer method. Finally, using the Design Exploration module and taking cooling water jacket inlet temperature and velocity as the input parameters, the head exhaust valve bridge zone temperature response were analyzed. Simulation results show that the head exhaust valve bridge zone temperature increases with the inlet temperature rising and decreases with the inlet velocity increasing, but as the inlet velocity reaches a certain value the temperature increases with the inlet velocity increasing conversely. While at cooling water inlet temperature of 353.31K and velocity of 4.876 m/s, the exhaust valve bridge zone temperature is minimal.