电压波形对介质阻挡等离子体放电特性和体积力的影响

Influence of Voltage Waveform on Discharge and Thrust of Dielectric Barrier Discharge Plasma Actuator

驱动电压波形对于介质阻挡放电等离子体激励器的放电状态和激励性能均有影响。基于典型构型的介质阻挡放电等离子体激励器(DBDPA)在静止大气中的放电实验,通过电学测量和电子天平测力,分别获得了不同驱动电压波形下DBDPA的放电电流–电压信号和射流产生的时均反推力等物理量。驱动电压波形主要包括正弦波、方波、对称三角波和正、负斜波。基于伏安特性图分析了放电电流、微放电电流脉冲等特性,基于Lissajous图分析获得了放电功率,初步讨论了沉积电荷对DBDPA起始放电的影响。结果表明:驱动电压波形所决定的电压变化率直接影响激励器的回路电流和等离子体微放电电流脉冲形态。放电中的表面沉积电荷形成虚拟电极,其在裸露电极极性发生反转时加强了电极间的电场,降低了起始放电电压阈值,使得放电得以提前。所有驱动电压波形中,方波驱动电压产生的时均反推力和放电功率均相对较大,正弦波次之,其余波形相对最小。其中,50%占空比方波产生的2个量最大。

For the dielectric barrier discharge plasma actuator （DBDPA）, both the discharge and the actuation performance will be influenced by the driving voltage waveforms. The investigation was based on the classic DBDPA and its discharge in static atmosphere driven by several voltage forms including sine, symmetry triangle, positive and negative ramp, and 25%, 50%, 75% duty-cycle square. By the electronic balance and oscilloscope probe measurement, the thrust, the electric current, and the voltage signal were acquired. The features of the circuit current and the microdischarge current pulses were analyzed, the discharge power was obtained by Lissajous figure, and the deposited surface charge influencing the threshold voltage of discharge was discussed preliminarily. The results reveal that the voltage slew rate depending on the voltage waveform is the main factor affecting the circuit current and the microdischarge current pulses. The threshold voltage of discharge is ~rned down and the ignition of plasma discharge is shifted to an earlier date by the virtual elec- trode formed by deposited surface charge which can reinforce the electric field between electrodes when the polarity of exposed electrode is changed. Both the time-averaged thrust and discharge power produced by the square wave driving voltage are relatively larger, the ones produced by the sine wave are smaller, and the relatively smallest ones are produced by the remaining waveforms. Of all, both the maximum time-averaged thrust and the maximum discharge power are produced by the square wave with 50% duty cycle.