Effect of Wavy Micro Plasma Actuator Arrangement on Suppression of Flow Separation

Abstract

Recently, plasma actuators have attracted attention as a new fluid control device. In this study, micro plasma actuators with an electrode width of millimeter order or less was applied to suppress the flow separation from NACA airfoil. The electrode geometry of the micro plasma actuators was sinusoidal electrodes. Jets induced by wavy electrodes collide with each other to form streamwise vortex. Streamwise vortex mixes the momentum inside and outside the boundary layer around the airfoil and suppresses flow separation. We used the square-type and staggered-type with four rows of sinusoidal electrodes. These plasma actuators were attached to the surface of airfoil. Flow visualization and PIV analysis were used to verify how the suppression of flow separation differs depending on the streamwise vortex and jet. The results showed that staggered-type, which induced streamwise vortex as the jet due to the plasma actuators was not pushed by the reverse flow and winds up, was more effective in suppression of flow separation than square-type.