H2/O2 THREE-BODY REACTION RATES AT HIGH TEMPERATURES (PC-121)

THE OPERATION OF A SCRAMJET PROPULSION SYSTEM REQUIRES THAT THE FUEL BE EFFICIENTLY BURNED UNDER CONDITIONS OF LOW STATIC PRESSURE AND HIGH INTERNAL VELOCITIES RELATIVE TO CONVENTIONAL PROPULSION SYSTEMS. SIMPLE CALCULATIONS OF ENERGY EXTRACTION BASED ON EQUILIBRIUM CHEMISTRY ARE NOT VALID UNDER THESE CONDITIONS BECAUSE MANY OF THE BIMOLECULARPROPAGATION AND TERMOLECULAR RECOMBINATION REACTIONS ARE SLOW. THE USE OF FINITE RATE CHEMISTRY TO MODEL THIS SYSTEMIS HINDERED BY OUR POOR KNOWLEDGE OF MANY OF THE THREE-BODY RATE COEFFICIENTS, MOST OF WHICH WERE MEASURED USING SHOCK TUBES OR INFERRED FROM FLAME MEASUREMENTS. WE PROPOSE TO USE INNOVATIVE LASER-INDUCED FLUORESCENCE DIAGNOSTICS IN A UNIQUE FACILITY TO MEASURE THESE RATES AT HIGH TEMPERATURES. LASER FLASH PHOTOLYSIS OF PARENT COMPOUNDS WILL BE EMPLOYED TO CLEANLY PRODUCE THE RADICAL SPECIES OF INTEREST. IN PHASE I OF THE PROGRAM WE PROPOSE TO DEMONSTRATE THE CAPABILITY OF THE SYSTEM BY MEASURING ONE OF THE THREE-BODY RATES AT A TEMPERATURE OF 1000 K AND DETERMINING THE SENSITIVITY OF THE DIAGNOSTIC METHOD. PHASEII OF THE PROGRAM WOULD MEASURE SEVERAL THREE-BODY RATE COEFFICIENTS AS A FUNCTION OF TEMPERATURE.