Nanosecond plasma actuation by a bending actuator mounted on a sharp edge in quiescent air

Abstract

An experimental investigation of the actuation characteristics of a repetitive nanosecond pulsed dielectric barrier discharge from bending plasma actuators mounted on a sharp edge is conducted. Four bending actuators with different bending angles are tested and compared with a planar actuator in quiescent air using schlieren imaging and electrical measurements. The results show that when fed by the same pulse, the plasma morphology, current waveform, and energy consumption of the bending and planar actuators are very similar. However, the thermal perturbations and induced flows differ significantly. In this experiment, at a low load voltage (V = 10–14 kV), when the plasma discharge is in the diffuse mode, the bending actuator can induce a stronger vortex and near-wall jet than the planar actuator, and as the bending angle decreases, the strength of the induced jet increases rapidly. At a higher load voltage (V = 18–20 kV), when the discharge is in the constricted mode, the plasma filaments produce hot plumes with both the bending and planar actuators, but the hot plumes from the bending actuator are injected into the air with a larger incidence. During the streamer-to-filament transition (V = 16 kV), induced flows from small-bending-angle (30° and 60°) actuators are characterized by a thickened near-wall jet, while those from the planar actuator are characterized by hot plumes.