LOW-SPEED VISUALIZATION STUDIES OF COUPLED AND UNCOUPLED VORTEX SYSTEMS ON CHINE-FOREBODY/DELTA WING CONFIGURATIONS TO HIGH ANGLES OF ATTACK

FOREBODIES WITH VORTEX-GENERATING SIDE EDGES OR CHINES BLENDING INTO HIGHLY SWEPT LEADING EDGES ARE KNOWN TO STABILIZE THE LEADING EDGE VORTICES THROUGH AERODYNAMIC COUPLING AT HIGH ANGLES OF ATTACK. HOWEVER, IN POST-STALL MANEUVERING FLIGHT CHINE VORTEX INTERACTION WITH WING AND VERTICAL TAILS CAN LEAD TO ROLL AND YAW SENSITIVITY TOGETHERWITH REDUCED OR NEGATIVE DAMPING, MAKING THE CONFIGURATION PRONE TO DEPARTURE. THIS RESEARCH WILL EXPLORE THE FEASIBILITY OF DECOUPLING THE CHINE AND WING VORTICES BY APPLYING THREE ALTERNATE GEOMETRICAL MODIFICATIONS PROPOSED, WHOSE EFFECTIVENESS ON A GENERIC DELTA FIGHTER CONFIGURATION WILL BE INVESTIGATED, THROUGH LOW-SPEED WIND TUNNEL FLOW VISUALIZATIONS IN A BROAD ANGLE OF ATTACK AND SIDESLIP ENVELOP. IT IS ANTICIPATED THAT AN EFFECTIVE METHOD OF REALIZING UNCOUPLED VORTEX FLOW FIELD WILL BE IDENTIFIED, PROVIDING A BASIS FOR A SUBSONIC/TRANSONIC WIND TUNNEL FORCE/MOMENT TEST PROGRAM IN PHASE II AIMED AT QUANTIFYING THE AERODYNAMIC IMPLICATIONS OF VORTEX DECOUPLING, INCLUDING REYNOLDS NUMBER EFFECTS.