弹簧压并状态下悬架减振器绕流涡旋特性分析

为研究汽车行驶过程中减振器弹簧压并状态下翼子板内流场特性的变化,将该状态下的减振器简化为三维变截面圆柱模型,并建立变截面圆柱绕流三维流场模型,利用Transition SST四方程转捩模型模拟低、中、高3种车速对大、小圆柱绕流涡旋特性的影响.结果表明:绕流后尾涡的大小、形态、上升角均受圆柱直径、雷诺数及边界条件的影响,在变截面处验证“下洗”运动对N区边缘涡生长的直接作用及对L区涡旋分布的干扰作用;3种流速下适合绕流涡旋振动压电能量回收的最优夹角分别为±10°,±15°,±20°;在有界的高雷诺数流场下对变截面圆柱绕流涡旋重新分区,发现新的涡旋连接方式.

Analysis on Flow Around Vortex Characteristics of Suspension Shock Absorber of Spring as Pre-Pressing State

In order to study the change of flow field characteristics in the fender when the spring as pre-pressing state in the process of vehicle driving, the shock absorber in this state was simplified into a three-dimensional step cylinder model, and the three-dimensional flow field model of step cylinder was established. The Transition SST four equations transition model was used to simulate the effects of low, medium and high vehicle speeds on the flow around vortex characteristics of large and small cylinders. The results show that the size, shape and rising angle of wake vortex are affected by cylinder diameter, Reynolds number and boundary conditions. The direct effect of “downwash” motion on the growth of edge vortices in N zone and the interference effect on vortex distribution in L zone are verified at the step section. The optimal angles for the energy recovery of flow around vortex vibration at three flow rates are ±10°, ±15° and ±20°. In the bounded high Reynolds number flow field, the flow around vortex of the step cylinder was zoned, and the new vortex connection mode was found.