DEVELOPMENT OF A STORABLE INJECTANT SYSTEM FOR SOLID ROCKET PERFORMANCE IMPROVEMENT

THE CONCEPT OF INJECTING HYDROGEN INTO THE COMBUSTION CHAMBER OF SOLID ROCKET MOTORS TO INCREASE PERFORMANCE HAS, THEORETICALLY, SUBSTANTIAL BENEFITS. THE HYDROGEN, OR OTHER LOW MOLECULAR WEIGHT COMPOUNDS, MAY PRODUCE A SIGNIFICANT INCREASE IN SPECIFIC IMPULSE BY DEPRESSING THE MOLECULAR WEIGHT OF THE COMBUSTION PRODUCTS. THE GOAL OF THIS EFFORT IS TO DEVELOP A CONCEPT THROUGH WHICH A STORABLE SYSTEM COULD BE USED TO INJECT A LIQUID OR GAS TO IMPROVE THE PERFORMANCE OF A SOLID ROCKET. METHODS OF GENERATING A LOW MOLECULAR WEIGHT COMPOUND, SUCH AS HYDROGEN, IN A GASEOUS FORM FOR INJECTION INTO THE SOLID ROCKET EXHAUST GASES WILL BE DEVELOPED. SOME APPROACHES TO BE CONSIDERED FOR HYDROGEN GENERATION WILL BE: (1) REACTION OF AN ACID OR WATER WITH A METAL, (2) DECOMPOSITION OF A METAL HYDRIDE, OR (3) DECOMPOSITION OF AN ORGANIC HYDRIDE. THESE APPROACHES WILL RESULT IN ESSENTIALLY A SEPARATE GAS GENERATOR TO SUPPLY A LOW MOLECULAR WEIGHT COMPOUND TO THE SOLID PROPELLANT GRAIN. ANOTHER APPROACH IS DIRECT INJECTION OF A METALLIC HYDRIDE WHICH WOULD LIBERATE HYDROGEN DURING THERMAL DECOMPOSITION FOR MOLECULAR WEIGHT REDUCTION, WHICH MAY ALTER THE COMPOSITION OF THE PROPELLANT GRAIN. THE KEY ISSUES TO BE RESOLVED ON THE CONCEPTUAL LEVEL IN THIS EFFORT ARE THE FOLLOWING DETERMINATIONS: (1) THE OPTIMAL INJECTION FOR VARIOUS SOLID FUEL COMPOSITIONS, (2) A PRACTICAL MEANS OF PRODUCING AND INJECTING THE FLUID, AND (3) THE IMPACTS ON OVERALL VEHICLE PERFORMANCE.