Lift Enhancement of a Pitching Airfoil in Dynamic Stall by DBD Plasma Actuators

Abstract

A dielectric barrier discharge (DBD) plasma actuator was applied to control leading-edge flow separation on periodically oscillated NACA 0012 airfoil. The effectiveness of flow control by the plasma actuator was investigated through pressure measurements on the surface of the airfoil. All of the cases exhibited a higher cycle-integrated lift and an improvement in the lift cycle hysteresis. The lift enhancement by the plasma actuator was sensitive to frequency of unsteady actuator operation. The maximum peak of efficiency of lift enhancement was observed around F=0.5. The time-resolved PIV measurement was also conducted to understand the flow control mechanism by the plasma actuator. The clear vortices appeared at the leading-edge at high angle of attack, and moved along the airfoil surface toward trailing edge. These vortices bring entrainment of main flow and the lift enhancement of the oscillating airfoil can be achieved.