AN ADVANCED METHOD FOR STAGNATION ENTHALPY ADDITION AND RECONSTRUCTION IN HYPERSONIC WIND TUNNEL TESTING

THE CHARACTERIZATION OF FLIGHT BEHAVIOR IN THE HIGH-HYERSONIC DOMAIN (MACH 5-20) AND AT ALTITUDES FROM 1-3X10(5) FEET (30-100 KM) HAS GREAT RELEVANCE FOR THE DESIGN AND DEVELOPMENT OF THE AOTV, NASP, AND HYPERSONIC REENTRY VEHICLES. DEFICIENCIES IN OUR PRESENT KNOWLEDGE AND UNDERSTANDING OF THE THERMOCHEMICAL, MATERIAL PROPERTY AND MATERIAL BEHAVIOR DATA BASE, INTRODUCED BY LIMITATIONS IN WIND TUNNEL SIMULATION TECHNOLOGY, HAVE IMPOSED CONSTRAINTS ON THE UNDERSTANDING OF CRUCIAL AEROTHERMAL BEHAVIOR AREAS INFLUENCED BY STAGNATION HEATING AT HIGH-HYPERSONIC VELOCITIES. TO ELIMINATE THESE TEST SIMULATION DEFICIENCIES, WHICH ARE PRIMARILY MANIFESTED IN ENTHALPY DEFICIENCIES IN THE MODEL STAGNATION ZONE, WE PROPOSE AN INNOVATIVE TECHNIQUE THAT EMPLOYS MICROWAVES TO SELECTIVELY HEAT THE STAGNATION ZONE ON MODELS UNDER TEST, SO THAT THE ENTHALPY CONDITIONS OF TRUE OPERATIONAL FLIGHT CAN BE RECONSTRUCTED. IN PHASE I WE WILL DEMONSTRATE THE FEASIBILITY OF OUR APPLICATION OF MICROWAVE TECHNOLOGY, CHARACTERIZE THE KEY AEROTHERMAL AND PLASMA INTERACTION PARAMETERS, AND ESTABLISH THE BASES FOR PROOF-OF-PRINCIPLE EXPERIMENTS TO BE PERFORMED IN PHASE II. THE PROPOSED TECHNIQUE OF ENTHALPY RECONSTRUCTION COULD GUIDE THE DEVELOPMENT OF MODEL EQUATIONS AND THE VERIFICATION OF BENCH MARK COMPUTER CODES, THUS PROVIDING QUALITY AEROTHERMAL DATA FOR IMPROVED DEFINITION OF VEHICLE BEHAVIOR IN FLIGHT.