μs脉冲等离子体气动激励特性的实验研究

Experimental Investigation on Characteristics of Microsecond Pulsed Plasma Aerodynamic Actuation

等离子体气动激励特性的测试诊断是揭示等离子体流动控制物理作用机制的重要基础。为此,主要在常规大气环境条件下,对μs脉冲等离子体气动激励特性进行电、光谱和流动特性的综合测试诊断实验研究。实验结果表明:μs脉冲放电的本质是丝状放电,在一个周期内,放电集中在正电压脉冲和负电压脉冲的上升沿;随着激励电压幅值增大,发射光谱强度增大,但表征电子温度和密度的典型谱线比变化不大;在放电的起始阶段,等离子体气动激励诱导了启动涡,启动涡随后发展成近壁面射流;激励电压和脉冲重复频率越大,等离子体气动激励诱导体积力越大;μs脉冲等离子体气动激励为非定常激励,消耗的功率比激励电压波形为连续正弦波时减小约30%,对于等离子体流动控制研究更为有益。

The diagnosis of plasma aerodynamic actuation characteristics is the basis of plasma flow control. Therefore, the electric, emission spectrum and flow characteristics of microsecond pulsed plasma aerodynamic actuation in conventional atmospheric environment were diagnosed synthetically. Experimental results indicate that the mode of microsecond pulsed discharge is filamentary discharge. Discharge occurs at the acceleration edge of positive and negative pulse. As the amplitude of actuation voltage increases, the intensity of emission spectrogram increases, while the emission intensity ratios which indicate the electron temperature and electron density remain unchanged. The ＂ Starting Vortex＂ and ＂Steady Jet＂ induced by pulsed plasma aerodynamic actuation were demonstrated by PIV test results. As the amplitude and pulse repetition frequency of actuation voltage increase, the body force induced by plasma aerodynamic actuation increases. Compared with traditional plasma aerodynamic actuation whose actuation voltage is continuous sine wave, microsecond pulsed plasma aerodynamic actuation is more advantageous for plasma flow control, which requires unsteady actuation and lower power consumption.