"AERODYNAMIC CONTROL OF NASP-TYPE VEHICLES THROUGH VORTEX MANIPULATION"

RESEARCH STUDIES HAVE SHOWN THAT THE AERODYNAMIC FORCES AND MOMENTS OF FIGHTER AIRCRAFT AND MISSILE CONFIGURATIONS CAN BE CONTROLLED BY MANIPULATING THE VORTICES WHICH DOMINATE THE FLOW FIELD. THIS PROPOSED RESEARCH PROGRAM WILL INVESTIGATE THE FEASIBILITY OF USING SOME OF THESE SAME VORTEX CONTROL CONCEPTS FOR ACTIVE CONTROL OF NASP-TYPE CONFIGURATIONS AT ANGLES OF ATTACK REPRESENTATIVE OF TAKE-OFF AND THE APPROACH AND LANDING REGIMES. IT IS WELL KNOWN THAT NASP-TYPE CONFIGURATIONS, I.E. HIGH FINENESS RATIO OR HIGHLY SWEPT DELTA WING CONFIGURATIONS, CAN EXPERIENCE SIGNIFICANT LOW-SPEED HANDLING PROBLEMS. THIS STUDY AIMS TO SHOW THAT ALTERNATIVE METHODS OF AERODYNAMIC CONTROL CAN EITHER AUGMENT OR, TO SOME DEGREE, REPLACE CONVENTIONAL CONTROL METHODS. THE FIRST PHASE OF THE RESEARCH WILL CONSIST OF WATER TUNNEL FLOW VISUALIZATION EXPERIMENTS WITH PROPOSED NASP CONFIGURATIONS OR AN ACCEPTABLE "GENERIC" NASP CONFIGURATION. THE EXPERIMENTS WILL IDENTIFY THE MOST PROMISING METHODS OF CONTROLLING THE CRITICAL VORTICES INCLUDING LOCAL SURFACE BLOWING AND MINOR GEOMETRIC CONFIGURATION CHANGES THAT COULD BE PRODUCED BY THE CONTROLLED MOVEMENT OF SMALL NON-CONVENTIONAL CONTROL SURFACES. THE KEY TO THE POWER OF VORTEX MANIPULATION IS TOPRODUCE MAXIMUM FORCE INPUT TO THE AIRFRAME WITH MINIMUM ENERGY INPUT FROM THE CONTROL TECHNIQUE. SUCCESSFUL FEASIBILITY STUDIES WOULD LEAD TO FURTHER DEVELOPMENT THROUGH WIND TUNNEL TESTING IN A PHASE II PROGRAM.