整车模型下车轮对流换热系数影响因素分析

Analysis of Factors Affecting the Convective Heat Transfer Coefficient of Wheels Under the Whole Vehicle Model

针对汽车在行驶过程中车轮的散热问题,以某轿车、 245/45/R19子午线轮胎为研究对象,构建了汽车空气动力学整车模型。采用三维不可压缩雷诺平均N-S方程、RNG k-ε湍流模型对整车条件下的车轮进行对流换热分析,并研究了车身结构如前后轮眉、前后气帘等对车轮散热的影响,为改善车轮散热能力提供相关指导。结果表明:将前后轮眉y向内收分别将前后车轮的表面平均对流换热系数提升了7.82%、 7.44%;添加前后气帘能显著提升车轮胎面处的对流换热系数,前气帘出口在车轮胎面处能将前轮胎面的对流换热系数提升21.64%,后气帘出口在车轮外侧时能将后轮胎面的对流换热系数提升21.02%。

In response to the heat dissipation problem during the driving process of a car,this article takes a certain se-dan model,245/45/R19,as the research object and constructs an aerodynamic vehicle model.Using the three-dimensional incompressible Reynolds averaged N-S equation and RNG k-e.The turbulence model conducted convective heat transfer a-nalysis on the wheels under vehicle conditions,and studied the influence of body structures such as front and rear wheel arches,front and rear air curtains,etc.on the heat dissipation of the wheels,providing relevant guidance for improving the heat dissipation ability of the wheels.The results show that inward retraction of the front and rear wheel arches increases the average convective heat transfer coefficient on the surface of the front and rear wheels by 7.82%and 7.44%,respec-tively;Adding front and rear air curtains can significantly improve the convective heat transfer coefficient at the tire sur-face of the car.The opening of the front air curtain at the tire surface can increase the convective heat transfer coefficient of the front tire surface by 21.64%.When the opening of the rear air curtain is on the outside of the wheel,it can increase the convective heat transfer coefficient of the rear tire surface by 21.02%.