Explosive Hydrazine Decomposition Due to Rapid Gas Compression (Adiabatic Heating),
NATIONAL AERONAUTICS AND SPACE ADMINISTRATION LAS CRUCES NM WHITE SANDS TEST FACILITY
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White Sands Test Facility WSTF is presently conducting tests to determine the explosive decomposition properties of hydrazine when initiated by rapid gas compression adiabatic heating. During the development of hydrazine power systems, there have been strong indications that compression of gas bubbles entrained in liquid may have produced explosive decomposition. Testing to identify the conditions that would cause such explosions were initiated at Sundstrand Corporation using a standard U-tube type apparatus. In this apparatus, pressure andor shock waves were suggested as being the initiation for the observed explosion. The objective of this study was to design an apparatus that would eliminate the contact of the pressure andor shock waves with hydrazine and then repeat similar tests as conducted by Sunstrand. An apparatus was designed that contained a moveable diaphragm which separated the hydrazine from the pressurant source. In this system a specific gas ullage in the liquid hydrazine can be established and when the diaphragm is depressed during pressurization, the gas ullage is in turn compressed. The results indicated that compression of small gas nitrogen bubbles 0.73 cc were capable of causing hydrazine to explode. Hydrazine explosions were found to be dependent on the initial hydrazine temperature, gas bubble compression rate, and impurities in the hydrazine.