Active Flow Control on a Circular Cylinder via Streamwise-oriented Dielectric Barrier Discharge Plasma Actuators

Abstract

Flow control on a circular cylinder using streamwise-oriented Dielectric Barrier Discharge (DBD) plasma actuators was examined. These actuators generated pairs of counter-rotating streamwise vortices that influence overall flow characteristics. Particle Image Velocimetry (PIV) and aerodynamic force measurements were performed to analyze the flow control effectiveness. PIV measurements show that a streamwise-oriented DBD plasma actuator produced good suppression of flow separation at ReD = 3300 and the actuation effect was still discernible at higher ReD = 6530. However, this remarkable result was limited to region directly downstream of the exposed electrode where a downwash was present. Subsequent force measurements reveal a rise in both lift and drag acting on the cylinder when DBD plasma actuation was implemented. A maximum increase in lift coefficient ∆CL and drag coefficient ∆CD of 0.04 and 0.16 (+16%) were recorded, respectively. Surface pressure distributions estimated from PIV measurements indicate a pressure drop on the downstream-facing surface of the cylinder. The increase in streamwise pressure differential across the cylinder signifies a rise in drag acting on the cylinder.