AERODYNAMIC CONTROL OF THE F/A-18 USING FOREBODY VORTEX BLOWING

FIGHTER AIRCRAFT IN FUTURE AIR COMBAT WILL REQUIRE ADDITIONAL AGILITY AND MANEUVERABILITY TO BE EFFECTIVE. A KEY TECHNOLOGY TO IMPROVE AGILITY IS IMPROVED AERODYNAMIC CONTROL AT HIGH ANGLES OF ATTACK. TECHNOLOGY RECENTLY DEVELOPED ON GENERIC FIGHTER SHAPES FOR HIGH-ANGLE-OF-ATTACKAERODYNAMIC CONTROL THROUGH FOREBODY VORTEX MANIPULATION SHOULD NOW BE INVESTIGATED FOR APPLICATION TO A REAL OPERATIONAL AIRCRAFT CONFIGURATION. THIS PROPOSAL WOULD INITIATE RESEARCH TO UTILIZE PRESENT KNOWLEDGE OF FOREBODY BLOWING TECHNIQUES AND DEVELOP AN EFFECTIVE FOREBODY BLOWINGSCHEME THAT COULD BE APPLIED TO AND FLIGHT TESTED BY THE NASA F-18 HARV. THE PHASE I EFFORT WILL DETERMINE THE MOST EFFECTIVE PLACEMENT AND ORIENTATION OF BLOWING NOZZLES OR SLOTS ON AN F-18 MODEL TO CREATE THE LARGEST EFFECT ON THE FOREBODY VORTEX STRUCTURE WITH THE MINIMUM BLOWING RATE. WATER TUNNEL FLOW VISUALIZATION EXPERIMENTS IN THE EIDETICS 24X36-INCH WATER TUNNEL WILL BE USED IN CONJUNCTION WITH VIDEO AND PHOTOGRAPHS TO DOCUMENT THE VORTEX STRUCTURE WITH VARIOUS BLOWING SCHEMES OVER AN ANGLE-OF-ATTACK RANGE TO AT LEAST 60 DEGREES. RESULTS WILL PROVIDE GUIDANCE FOR PLANNING WIND TUNNEL FORCE AND MOMENT TESTS OF SUB-SCALE MODELS IN PHASE II AND FOR POSSIBLE TESTS OF A FULL-SCALE F-18 IN THE NASA AMES 40X80X120-FT. WIND TUNNEL. SUCCESSFULDEVELOPMENT OF A FOREBODY BLOWING SYSTEM IN PHASE II WOULD LEAD TO FULL-SCALE FLIGHT TESTS ON HARV.