基于等离子体流动控制的方背式汽车模型减阻研究

通过风洞试验,开展了关于表面介质阻挡放电(SDBD)等离子体激励器对方背Ahmed模型尾部分离流动的控制效果的研究。通过PIV速度测量,揭示了静态环境下激励器诱导离子风的气动特性,然后通过模型表面压力和尾部流场的变化,分析了在激励电压下模型的减阻率,并阐述了其减阻机理:等离子体激励器可有效控制尾部流动,提高模型尾部压力,从而达到减阻的目的。试验结果表明,随着风速提高,激励器控制效果减弱,在17 kV的峰值电压下,激励器可获得最大诱导速度;因此,在10 m/s的风速和17 kV的峰值电压下减阻效果最佳,主动减阻率为-4.58%,总减阻率达-9.02%。

Study on Drag Reduction of Square-back Ahmed Model Based on Plasma Flow Control

The control effects of the surface dielectric barrier discharge-based plasma actuator on the wake flow separation of squire-back Ahmed model are studied by wind tunnel test in this paper.Firstly,the aerodynamic characteristics of ion wind induced by plasma actuator under static state environment are revealed through particle image velocimetry.Then according to the changes in the surface pressure and wake flow field of the model,the drag reduction rates of the model at different actuating voltages are analyzed with the mechanism of drag reduction expounded:plasma actuator can effectively control wake flow,increasing the wake pressure and hence leading to the reduction of aerodynamic drag.Test results show that the control effects of actuator weaken with the rise of wind speed and the induced speed of actuator reaches maximum at a peak voltage of 17 kV.Thus,the best drag reduction effect is achieved in a condition of a wind speed of 10 m/s and a peak voltage of 17 kV with an active drag reduction rate of-4.58%and a total drag reduction rate of-9.02%.