关键词: 前舱, 温度场, 计算流体力学, 辐射换热, 导流

Abstract:

During underhood temperature field experimental development for some passage cars, surface temperature of drive shaft oil seal and battery is in excess of the limit. To find the reason, detailed CFD model of underhood for air flow and heat transfer analysis was established. The temperature boundary conditions for main heat resources were obtained by experiments, and the radiation heat transfer was also considered. The air flow distribution and temperature field in underhood under test conditions were solved. Simulation results indicate that, over high temperature of drive shaft oil seal is because of that oil seal is very close to hot resource while the air flow velocity around it is small, for battery it is owing to flow circumfluence through radiator and fan which causes that air blowing to the battery surface is repeating heated. Based on this, structure to guide cool air and heat insulation were added near drive shaft oil seal and battery, and their shapes were optimized by CFD simulation, and the final effect was validated by experiments.It is shown that measured temperature of oil seal and battery reduces significantly, the underhood temperature overhigh issues are then eliminated.

Key words: underhood, temperature field, computational fluid dynamics(CFD), radiation heat transfer, guiding flow