汽车侧风稳定性的双向耦合方法研究

Research on the Two-Way Coupling Method for Vehicle in Crosswind Condition

基于汽车空气动力学与系统动力学双向耦合提出了一种Fluent与Matlab的在线耦合算法.并对侧风工况下某微型面包车的气动以及稳定性进行研究.汽车在9m/s的稳定侧风环境下行驶1s,双向耦合方法相对于传统的单向耦合方法计算得到的汽车侧向位移、侧向力、横摆力矩分别减小3.3%,4.8%,17.8%,相应的汽车侧向速度、横摆角速度等的差距都超过了6.0%.并且这种差距会随着作用时间的增加逐渐增大.结果表明:车辆运动状态受气动力的影响不能忽视;汽车的侧向力并不一定随着横摆角变大而增大,要综合考虑汽车的侧向速度与横摆角速度的影响;双向耦合方法建立了汽车空气动力学与系统动力学之间的紧密联系,得到的结果更加切合实际.

An on-line arithmetic was presented, coupling fluent with Matlab method, based on two-way coupling method of aerodynamics and system dynamics of vehicle to analysis the stability of a van in transient crosswind conditions. Compared with conventional analysis method, the new method achieves obvious results, when the van runs in crosswind condition of 9 m/s for 1 second, the final lateral displacement, force and yaw moment has a respective reduction of 3.3 % .4. 8% and 17.8%, the corresponding slip velocity, yaw velocity have a relative difference more than 6%. Moreover the gaps will enlarge with the time increasing. The analysis results indicate that, it should not be ignored that the aerodynamics has an effect on the state of vehicle moving; it is necessary to consider synthetically the effect of yaw and slip velocity, because the lateral force to vehicle is not always increase with yaw angle increasing; two-way coupling method has set up a close combination between aerodynamics and system dynamics of vehicle, being more suitable to actual circumstance.