某电动SUV后扰流板气动特性的研究

Research on Aerodynamic Characteristics of Rear Spoiler in an Electric SUV

汽车在高速行驶中的经济性和稳定性与汽车受到的空气阻力和升力直接相关。与传统燃油车相比,降低风阻对于电动汽车提升续航里程和降低能耗更加重要。本文中采用雷诺时均方法对某款纯电动SUV车型进行在120 km/h车速下整车外流场仿真分析,并将风阻系数和升力系数与等比例油泥模型风洞试验的结果进行了对比。采用常用的Realizable k-ε湍流模型对该SUV车型后扰流板进行仿真优化。研究了该SUV的后扰流板上表面不同倾斜角度对整车气动升力和阻力系数的影响;进一步,在最佳倾角的基础上,通过5种后扰流板通孔形式的对比分析,确定了最优状态的后扰流板。最终的验证试验结果表明,整车风阻系数降低3.9%,而升力系数的增加在可接受范围内。

The fuel economy and stability of vehicle in high-speed driving is directly related to the aerodynamic drag and lift of the vehicle.Compared with traditional fuel vehicles,reducing aerodynamic drag is much more important for electric vehicle in increasing driving mileage and lowering energy consumption.In this paper,Reynolds time-average scheme is adopted to conduct a vehicle external flow field simulation on a battery electric SUV at a speed of 120 km/h,with the results of drag and lift coefficients compared with that of the wind-tunnel test of clay model of the same scale.The common Realizable k-εturbulent model is used to perform a simulation optimization on the rear spoiler of that SUV to study the effects of the different declined angles of the upper surface of spoiler on the drag and lift coefficients of vehicle.Furthermore,on the basis of best angle obtained,the optimal state of rear spoiler is determined by the comparatively analysis on five different types of through holes on spoiler.The results of final validation test show that the aerodynamic drag coefficient reduces by 3.9%,while aerodynamic lift coefficient increases,but in acceptable range.