Energy crisis and environmental deterioration make people realize the need to improve fuel efficiency of vehicles,thereby promoting the research of vehicle aerodynamic drag reduction.In this paper,the Ahmed model featured with a rear slant angle of 30° was the research object,at the rear of which a vortex generator control device installed vortex generator control device at the rear,the control characteristics of vortex generators with different arrangement on the wake field investigated through seven-hole probe.The results show that there is a low-pressure separation area in the tail of the Ahmed model,the length of which is about 50％ of the total of the model,which is also the main reason for aerodynamic drag formation.The vortex generator arrangement has a great influence on the wake structure of the model,when the vortex flow generated by vortex generator moves in the same direction as that of the tail part of the model,the effect of flow control is obvious,longitudinal vortex strengthens the momentum mixing at the bottom of the vehicle,the relative pressure recovery coefficient of the model wake region can be increased by 6.94％,the length of wake region can be decreased by 40％.On the contrary,if the longitudinal vortex moves towards the opposite direction,it will impede the movement of the vortex flow at the tail part,which leads to the decrease of the pressure in the flow field of the model.%能源危机和环境恶化使人们意识到提高车辆燃油经济性的必要性,从而推动了车辆气动减阻技术的研究.选择具有尾部典型特征的30°倾角Ahmed模型为研究对象,通过在模型尾部安装涡流发生器控制装置,利用七孔探针测试技术研究了涡流发生器不同排列方式对尾流场的控制特性.结果表明,在实验状态下,Ahmed模型尾部存在大范围低压分离区,该分离区长度约为模型总长度的50％,是形成压差阻力的主要原因;涡流发生器排列方式对模型的尾流结构影响较大,当涡流发生器产生的流向涡与模型尾部分离涡运动方向相同时,分离流动控制效果明显,流向涡使得沿车身底层的动量掺混作用增强,模型尾流区的相对压差恢复系数可增加6.94％,尾流区长度降低40％;与之运动方向相反的流向涡会对模型尾部的分离涡运动产生阻碍作用,导致模型尾部流场中的压力降低.
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