刹车盘结构对车轮及整车流场的影响

为研究车轮刹车盘结构对旋转车轮和整车流场气动特性的影响,针对是否存在刹车盘两种情况分别建立等比例模型,采用可实现的k-ε两方程模型计算,对比分析气动升、阻力因数,表面压力因数及整体与局部流场,发现刹车盘结构在简化车体上对车轮局部和整车流场都具有突出影响,指出在整车气动特性模拟中刹车盘存在的必要性.进一步进行计算模型选择的研究,发现旋转壁面模型与多坐标参考系(Multiple Reference Frame,MRF)模型对旋转车轮的流场特性模拟结果有差异,在近车轮区域表现尤为明显.

Effect of braking disk structure on wheel and whole vehicle flow field

To study the effect of the braking disk structure on wheel and whole vehicle aerodynamic characteristics, based on the calculation with the realizable two-equation k-ε model, the aerodynamic lift and drag factors, surface pressure factor, and the local and whole flow fields are compared and analyzed for the full-scale vehicle models with or without braking disk. The results show that braking disk structure has remarkable influence on the fields of the partial wheels and the whole vehicle. It is necessary to consider the braking disk in the aerodynamic characteristics simulation of whole vehicle. The model selection is studied and it is found that the rotating wall model is different from the Multiple Reference Frame （MRF） model on the results of simulation on flow field characteristics of rotating wheels, especially at the flow field around the surface of wheels.