汽车车轮周围气流场的数值模拟研究

Numerical Simulation for Airflow Field around Car Wheels

运动车轮周围气流场对地面扬尘及轮胎磨损颗粒物的运动有很大影响。使用旋转壁面技术模拟车轮滚动,建立了车辆-轮胎空气动力学模型并进行了试验验证,对车轮周围气流场进行了三维数值模拟。结果表明:气流在轮胎-轮罩间隙中存在相汇区并形成涡流,气流主要从相汇处溢出。扬尘及颗粒物主要围绕涡流动并获得动能脱出。气流在前、后轮的泵吸效应显著,但前轮气流倾向于向外侧发散,后轮附近气流场倾向于向上发散。气流在车尾会形成马蹄涡和拖拽涡。

The airflow field characteristics around the wheels have great influence on the flying of road dust and tire wear particles. Using the rotating wall boundary technology, an aerodynamic model of the vehicle-tire was built and verified. The airflow field around the wheels was obtained. The results show that the two airflows between the wheel and the wheel guard meet leading to the vortex. The airflows mainly overflow near the intersection. Due to the significant pumping effects, the airflow tends to fly to outside and upward near the front and rear wheels, respectively. In the rear of the car, the airflow forms a couple of horseshoe-shaped vortex and two pairs of dragging vortex.