Control of vortices on a delta wing by leading-edge injection

Abstract

This experimental investigation addresses the control of flow past a half-delta wing at high angle of attack. Application of steady blowing, steady suction, or alternate suction-blowing in the tangential direction along the leading edge of the wing can retard substantially the onset of vortex breakdown and stall. The most effective period of the alternate suction-blowing is on the order of one convective time scale of the flow past the wing. As a result of this type of control, the vortex structure in the crossflow plane is modified from a fully stalled condition to a highly coherent leading-edge vortex. This transformation to a restabilized vortex is represented by instantaneous velocity fields, streamline patterns, and vorticity contours