锯齿电极等离子体激励器诱导流场特性分析

On the Flowfield Induced by Plasma Actuator With Serrate Electrode

本文通过2D PIV及其CCD相机获取锯齿电极等离子体激励器在静态环境下诱导的流场结构以及放电图像。CCD相机拍摄的放电图像显示该激励器在锯齿中间存在一暗带区域,而不同截面的流场结果则验证了该型激励器能够诱导出带涡对三维射流结构,涡对贴近壁面向下游发展,并在激励器壁面上方诱导出下洗流。文中结合各拍摄截面的流场结构以及放电结构,分析了该型激励器诱导的流场结构特性,涡对发展规律和形成原因,以及锯齿电极激励器的放电特性,最后提出了其流场诱导机理模型。

This paper presents the results of an experimental investigation aiming at studying the flow field induced by dielectric-barrier-discharge（DBD） plasma actuator with serrate electrodes in still air.Experiments were carried out using Particle image velocimetry（PIV）.Particular attentions were given to theflow topology,discharge characteristic and vortex formation mechanism.PIV results showed that a three-dimensional flow field was created by the serrated DBD actuators.Where a two-dimensional wall jet is induced by the widely used linear electrode actuators,plasma actuators using serrate electrode introduce a 3D jet combined with streamwise vorticity.which may be of great use in flow control（e.g.mixing of local fluid）.CCD imaging experiment verified that there existed obviously point discharge at the serrate tip which might be useful in nanosecond pulse exciting which has been research focus and holds great potential.In addition,an idealized conceptual model was proposed to show the flow topology induced by the serrated DBD actuator.