高海拔车用散热器传热特性影响因素研究

Study on Influencing Factors of Heat Transfer Characteristics of Vehicle Radiator at High Altitude

针对汽车在高原长时间爬坡引起发动机过热问题,对车用散热器传热特性开展研究。根据空气物性参数随海拔高度的变化规律,基于CFD计算流体传热仿真,采用Fluent-DM创建散热器仿真模型,研究变海拔高度以及迎面风速对车用散热器换热特性的分析。结果表明,大气密度的改变是影响散热器换热性能的主要因素,随着海拔高度增加和迎面风速减小,空气流体域雷诺数呈现下降趋势,同时空气流体域对流换热系数相应减小,使车用散热器的高原散热能力降低。

Aiming at the problem of engine overheating caused by long time climbing on plateau,the heat transfer characteristics of vehicle radiator were studied.According to the change rule of air physical parameters with altitude,fluid heat transfer simulation was calculated based on CFD,and Fluent-DM was used to create a radiator simulation model to study the analysis of heat transfer characteristics of vehicle radiator with varying altitude and head-on wind speed.The results show that the change of atmospheric density is the main factor affecting the heat transfer performance of the radiator.With the increase of the altitude and the decrease of the headon wind speed,the Reynolds number in the air fluid domain decreases,and the convective heat transfer coefficient in the air fluid domain decreases correspondingly,which reduces the plateau heat transfer capacity of the vehicle radiator.