两车速度对超车过程轿车气动特性的影响

Influence of velocity on aerodynamic characteristics of cars in overtaking process

利用动网格技术对超车过程中两种相对速度下车辆周围非定常流场进行了数值模拟,得到超车车辆和被超车辆受到的侧向力、侧倾力矩和横摆力矩在超车过程中的变化情况,并根据两种速度情况下的流场特性,分析其对气动力特性的影响.计算结果表明:超车速度越大,被超车辆最大侧向力、侧倾力矩和横摆力矩越大;超车车辆最大侧向力、侧倾力矩越大,横摆力矩越小.

The unsteady flow fields around overtaking and overtaken cars in overtaking process at two different speeds were numerically simulated with moving mesh technology. The side forces, rolling moments and yawing moments of the cars during the overtaking process were calculated and analyzed. The influences of the flow field on the aerodynamic ／ forces were analyzed according to the distribution of velocity and pressure fields. The results show that the maximum side force, rolling moment and yawing moment of the overtaken vehicle become bigger, the maximum side force and rolling moment of the overtaking vehicle will become bigger, the yawing moment will become smaller with the increase of the overtaking speed.