ENHANCED LIFT THROUGH DYNAMIC FLOW MANIPULATION

1A multi-segmented dynamic leading-edge flap system is proposed as a candidate for lift enhancement through dynamic flow manipulation. Delta wings with sweep angles of 60 degrees or more will be fitted with the proposed leading-edge device of 3 or more flaps. Each flap is controlled with a high-speed digital linear stepper motor and is capable of executing autonomous oscillations. It is intended to capitalize on excitation of helical instability waves of clockwise and counterclockwise spin on the separated leading-edge vortex to manipulate the pressure distribution along the vortex core. This in turn affects the location of vortex breakdown which could lead to enhanced lift and super-maneuverability of a delta or cropped delta wing aircraft. A parallel effort will be spent on incorporating piezo-electric oscillator/exciters on swept wing leading edges, which will dynamically manipulate camber distribution along the wing span in a 3-D fashion. With the proper choice of the driving frequency (i.e., nondimensional Strouhal number), a resonant flow behavior can be excited, which in turn eliminates the need for large-amplitude leading-edge oscillations. We currently estimate a maximum angular oscillation amplitude of +/- 5 degrees.