Compressible Dynamic Stall Control Using a Shape Adaptive Airfoil

Abstract

Compressible dynamic stall control using a dynamically deforming leading edge airfoil is reported. The technique uses real-time leading edge shape adaptation to manipulate the local adverse pressure gradient over an oscillating airfoil. This produces attached leading edge flow at all angles of attack in the cycle. The shape change schedule is tailored to achieve the “right” airfoil shape through the dynamic stall regime by rounding the nose on the upstroke and sharpening it on the downstroke. The method exploits the favorable effects of shape adaptation on the potential flow to modify the pressure field and maintain the peak vorticity level below the critical level at which the dynamic stall vortex develops. The sensitivity of the flow to rate of nose curvature change and the angle of attack at which the initiation occurs has been investigated.