汽车悬架减振器绕流涡旋动态特性分析

为了麦弗逊悬架运动造成其翼子板内流场特性多变的问题。通过将该问题简化为绕流圆柱平面流场，首先利用 SST方程对静态的圆柱绕流体模型进行理论计算和仿真，获得了稳定涡旋下的升力、阻力系数及斯特劳哈尔数等特征值。在此基础上，分析空气流速、减振器直径、横向振动频率和振幅等结构和动力学参数对涡旋动态特性的影响，获得了平均升力系数和瞬时阻力系数曲线的拟合方程。结果表明，斯特劳哈尔数的最大误差为5%，简化模型忽略减振器结构的三维效应是可以接受的；脱涡频率与减振器直径的倒数成二次关系；横向振动频率则对动态脱涡频率起到了关键作用，且对流场的压力分布影响显著，而横向振幅对无边界流场条件下的涡旋特性及压力场分布影响不大。

Analysis of the Dynamic Dortex Characteristics of the Flow Past the Automotive Suspension Shock Absorber

The problem of variable flow field characteristics in the fenders caused by MacPherson suspension is one of the difficulties that hamper the energy regeneration of swirling around the shock absorber. This problem is simplified as a flow past the cylindrical in two-dimensional space. First, using the SST equation to perform theoretical calculations and simulations on a static cylindrical flow model, the characteristic values of lift, drag coefficient and Strouhal number et al. under stable vortex are obtained. On this basis, the effects of structural parameters such as air velocity, shock absorber diameter, transverse vibration frequency and amplitude on the dynamic characteristics of the vortex are analyzed, and the fitting equations of the average lift coefficient and the drag coefficient curve are obtained. The results show: the maximum error of Strouhal number is 5%; the simplified model that ignores the three-dimensional effect of the shock absorber structure is acceptable; the frequency of vortex shedding is in quadratic relation to the inverse of the shock absorber diameter; transverse vibration frequency plays a key role in the frequency of dynamic vortex shedding; and transverse vibration frequency has a significant influence on the pressure distribution of the flow field; the lateral amplitude has little effect on the vortex characteristics and pressure distribution under the boundaryless flow field conditions.