Reactive flow control of delta-wing vortex

In this paper, the reactive flow control of delta-wing leading-edge vortices using along-core pulse-width-modulation flow injection is presented. Leading-edge vortices on the upper surface of a delta wing can augment lift. Manipulating breakdown points of leading-edge vortices can effectively change the delta wing's lift and drag and generate attitude-control torque. In this paper, a black-box dynamic model for active flow control of vortex breakdown points is identified from wind-tunnel data using a model scheduling method. Based on the identified model, a closed-loop active flow controller is developed. Simulation and real-time wind-tunnel test show that the closed-loop controller can effectively manipulate the upper surface pressure of the delta wing, which indicates that the closed-loop controller can effectively control vortex breakdown points.