Pulsed Velocity Created by a Plasma Actuator in the Vicinity of the Wall

Abstract

Surface dielectric barrier discharge plasma actuators, which have a few advantages and are involved in continuous and burst modes, have attracted worldwide attention for aircraft flow control in the last two decades. It is believed that understanding the flowfield generated by surface dielectric barrier discharge plasma actuators has a great effect on promoting the control effects of plasma actuators. Nevertheless, the details of the flowfield close to the wall remain unclear. Motivated by this requirement, the flowfield created by a single asymmetrical plasma actuator is investigated in still air by using the two-dimensional time-resolved particle image velocimetry device. Interestingly, a pulsed velocity created by the plasma actuator with the continuous mode near the dielectric surface is first observed, which might cause the impact effect by creating large-size disturbances, and benefits flow control. It is speculated that the formation of the pulsed velocity is related to the coupling effect between the entrainment of the starting vortex and the induced body force at the initiation stage closely. In addition, the present results reveal the underlying mechanism that the control effect of the burst pattern has significantly outperformed that of the continuous one.