Nanosecond Surface Dielectric Barrier Discharge Driven by Different Pulse Parameters for Airflow Control

Abstract

Plasma aerodynamic actuator based on nanosecond-pulse surface dielectric barrier discharge (ns-SDBD) is an effective technology for active flow control, which can significantly reduce power consumption and improve the aerodynamic characteristics. In this paper, the recent progress of nanosecond-pulse SDBD actuator is introduced. Then, investigation is performed on characteristics of ns-SDBD with different parameters (rise time, pulse width and PRF) of SDBD actuator with two-electrode structure, which has not been widely discussed in the literature. The nanosecond generator can provide a voltage of 0 ~ 15 kV, a rise time of 0 ~ 500 ns and pulse width at peak of 0~ 100 μs, respectively. Experimental results show that plasma discharge mainly takes place during the rise time and fall time, respectively. When the rise time increases, the amplitude of the current gradually decreases and multiple discharges occur, while the ignition of the discharge is delayed by tens of nanoseconds due to high ionization rate. Moreover, the discharge becomes relatively homogenous at the rise time of 50 ns but the plasma length is slightly affected by the rise time. The maximum deposited energy can be obtained at the rise time of 50 ns, little effect appears on the deposited energy when the rise time increases from 100 to 500 ns, which is positively related to the intensity of induced compression wave and propagation velocity. The peak velocity of induced pressure wave decreases from 408 m/s to 369 m/s when the rise time increases from 50 ns to 400 ns. Furthermore, it is shown that pulse width has slightly effect on the current amplitude and discharge uniformity, but longer pulse width will produce more deposited energy and induce two pressure waves. In addition, with the increase of PRF from 250 Hz to 1250Hz, the body force increases from 0.245 mN to 2.107 mN, which is proportional to PRF. To sum up, the actuator operated with short time, long pulse width and high frequency is conductive to shack interaction and airflow control.