Flow Control With EHD Actuators in Middle Post Stall Regime

We analyze the modifications of the flow around a NACA 0015 airfoil when the flow is perturbed with an electrohydrodynamic (EHD) actuator. The device used consists of two bare electrodes flush mounted on the surface of the model operated in a discharge regime characterized by the formation of a plasma sheet contouring the body in the interelectrode space. In this study, we analyze the influence on the aerodynamic performance of the airfoil in the middle post stall regime (angle of attack≈20o). The analysis is undertaken with measurements of the surface pressure distribution and of the flow fields with Particle Image Velocimetry technique. The experiments indicate that at moderate Reynolds numbers (150,000<Re<333,000), the actuator enables a reattachment of the flow and reveals an important sensitivity of the middle post stall regime to periodic excitation.