AC和NS等离子体激励对细长前体分离涡流场的控制

Flow Control over a Slender Forebody Using AC and NS-DBD Plasma Actuators

为了在更高的风速下实现圆锥前体分离涡的控制,了解AC-DBD和NS-DBD激励器的激励特性,应用交流(AC)放电和纳秒脉冲(NS)放电等离子体激励对20°顶角的圆锥-圆柱组合体圆锥段前体非对称流场进行主动流动控制实验。实验在低速开口风洞中进行,迎角45°,风速5～22m/s,流动控制方式为等离子激励器关闭、左舷或右舷等离子体激励器开启三种模式。结果表明:风速5m/s时,通过AC-DBD的左、右舷激励可控制圆锥前体的非对称流场实现镜像对称,NS-DBD则无明显作用效果;随着风速的提高,AC-DBD对非对称载荷的控制作用逐渐减小,与此同时NS-DBD的控制作用逐渐增加;风速22m/s时,NS-DBD可实现圆锥前体非对称流场的镜像对称控制,而AC-DBD则无明显作用效果;相对于AC-DBD等离子体激励,NS-DBD对于更高速度下的分离涡流场控制是有效的。

In order to control the vortex flow over conical forebody under higher wind ,and to understand the characteristic of the AC-DBD and NS-DBD ,alternative current（AC） and nanosecond pulse（NS） plasma dielec-tric barrier discharge（DBD） is applied to the active control of the asymmetrical vortices over the cone of the cone-cylinder .The experiment is performed in a low speed wind tunnel .The angle of attack is 45＆#176; and the wind speed ranges from 5 m/s to 22 m/s .Flow control modes of the actuator are plasma off ,port on and starboard on .The result shows that the asymmetrical field can be mirror symmetry control by port on and starboard on of AC-DBD at 5 m/s ,but the NS-DBD is not effective .As the wind speed increased ,the function of the AC-DBD on asymmetric vortices is gradually disappears ,meanwhile the function of NS-DBD is increasing .When the wind speed reaches 22 m/s ,NS-DBD can get the asymmetrical field mirror symmetry ,but the AC-DBD is not effective .This implies that the NS-DBD is more effective to control the separated vortices field at the higher w ind speed relative to the AC-DBD .