基于离散气动系数的轿车瞬态侧风稳定性研究

Research on Automotive Transient Crosswind Stability Based on Discrete Aerodynamic Coefficients

建立了在侧风作用一般情形下的汽车运动矢量关系,利用ADAMS Car建立了完整的轿车多体动力学模型;在整车外流场初步分析的基础上,利用该矢量关系将离散的气动六分力系数转化为侧风工况下的连续气动载荷,根据车身横摆角进行了数值拟合实时加载;按照ESV规范的要求进行了瞬态侧风稳定性仿真,探讨了气动载荷简化对侧风稳定性的影响规律,定量仿真的结果与外流场定性分析的结果一致,证明了该方法正确可靠。

The motion vector relation of a car was built under the action of crosswind in general case, a multi-body dynamics model of the car was established by using ADAMS Car. Based on the ex- ternal flow field analyses of body, the discrete aerodynamic six-component coefficients were translated into continuous aerodynamic forces by using the vector relation, the crosswind load was exerted in real time according to yaw angle of body; the transient crosswind stability simulation was executed accord- ing to ESV regulations. The influence rules of simplified aerodynamic load on erosswind stability were discussed, the quantitative simulation results are agree with the flow field qualitative analyses, which proves the correctness and reliabilitv of the method_