Effect of rise time on nanosecond pulsed surface dielectric barrier discharge actuator

Nanosecond pulsed surface dielectric barrier discharge (ns-SDBD) actuator is a novel technology for active flow control due to its high control capability and low power consumption. The electrical, and aerodynamic, characteristics of ns-SDBD actuator with different rise times are investigated by electrical measurement system, Schlieren optical system, and particle image velocimetry (PIV) system. Experimental results show that the short rise time leads to a high current amplitude and a diffuse-like plasma layer. The deposited energy reaches its maximum (9.26 mJ) at a rise time of 50 ns, and then declines, finally, slight changes occur when the rise time is increased from 150 ns to 500 ns. Furthermore, a circular arc wave and a plane wave are produced due to the localized heating. The intensity of the circular arc wave increases when the rise time decreases and the propagation distance of induced pressure waves in the vertical direction increases in a quasi-linear manner. In addition, due to the greater ability to transmit output energy to the surroundings, and the stronger tangential acceleration ability in the case of a short rise time, the area of action for the starting vortex is larger when rise time decreases and two vortexes are formed, which is conducive to mixing with the airflow and improving flow control capability.