Characteristics of pulsed surface arc discharge actuator and its verification of flow control over a Delta wing

Abstract

A actuation system composed of actuators, circuit board, and microsecond pulse power has been designed to conduct pulsed surface arc discharge (PSAD) actuation. The instantaneous impulse energy of PSAD is higher than that of typical dielectric barrier discharge. Schlieren imaging and particle image velocity (PIV) technique have been used to characterize the flow field changes caused by actuation in quiescent air. A localized pressure wave is induced by every actuation, propagating in the air almost at the speed of sound. Special emphasis is given on the hot air mass observed in schlieren imaging, generating thermal convection disturbances in the flow field. A pair of a weak reverse vortex is generated after discharge for each actuator, with the maximum propagation velocity of 0.1 m/s. The induced burst perturbations indicate that the mechanism of plasma flow control based on PSAD is instantaneous heat release generated by PSAD actuation. Wind tunnel experiments were conducted on a 30° sweep delta wing to investigate the aerodynamic control effects by using PSAD actuation. The 12-channel PSAD actuation can effectively improve the aerodynamic performance of the delta wing, delay the angle of attack from 14° to 18° and increase the maximum lift coefficient by 12.9%. In this article, PSAD actuation has the ability to control low speed fluid flow separation by releasing very strong discharge power.