基于CFD的双道超车过程气动特性分析

基于计算流体力学（CFD）中的动网格技术对双道超车进行了数值模拟，研究表明，双道超车过程中，3辆车周围均出现强烈的压强和空气流速变化，当主超车在两车之间时，流场变化更为复杂。随着车辆相对位置的变化，3辆车周围的涡形态发生明显变化，涡的变化消耗流场中的能量，使车身受力发生变化。行驶过程中，3辆车的侧向力、风压中心位置和横摆力矩均发生明显变化。绝对速度增加，主超车与被超车的最大侧向力均呈线性增长，给车辆行驶稳定性带来负面影响。

Aerodynamic Characteristics Analysis of Overtaking Process on Two-Lane Roads Based on CFD Simulation

Based on the moving mesh technology in computational fluid dynamics(CFD), the numerical simulation of the overtaking maneuver on two-lane roads was studied. The results show that in an overtaking process the lateral forces on the three vehicles increased first, then decreased, and finally stabilized. When the overtaking vehicle was between the two overtaken vehicles, the lateral forces fluctuated more frequently. With the change of the relative position between the vehicles, the centers of wind pressure at the three vehicles all moved forward, which affected the stability of the vehicles. When the absolute speeds of the overtaking and the overtaken vehicles increased, the maximum lateral forces on the three vehicles all increased linearly, which would reduce the vehicle running stability.