Pressure Oscillations in a Liquid Propellant Gun - Possible Dependence on Propellant Burning Rate
Final rept. Feb 1991-Jan 1992
ARMY BALLISTIC RESEARCH LAB ABERDEEN PROVING GROUND MD
Pagination or Media Count:
High frequency pressure oscillations have been observed in liquid propellant gun firing records, and modeling of the combustion process indicates that the oscillations are affected by the burning rate of the propellant. The HAN-based propellants have consisted of stoichiometric, aqueous mixtures of the nitrate salts of hydroxylamine HAN and an aliphatic amine AAN. These mixtures decompose sequentially because HAN is less stable thermally than is the AAN. Combustion is obtained when the products of the HAN decomposition react with the molten AAN droplets. The nitrate salts of tertiary amines result in the smoothest and most rapid combustion, and thus triethanolammonium nitrate TEAN is the AAN salt used in the propellants LGP1845 and LGP1846. Attempting to further raise the burning rate of the propellant mixtures requires circumventing the sequential nature of the reactions. Decomposition of hydroxylamine in which alkyl groups have replaced hydrogen should be essentially concomitant with HAN but reactive organic fragments will be available sooner and such mixtures should burn faster. Using the nitrate salt of N,N-diethylhydroxylamine DEHAN, a mixture containing 20 water was prepared. This propellant burns 17 times faster than LGPI846 and the combustion model indicates that the HAN-DEHAN mixture should essentially eliminate the observed pressure oscillations.
- Ammunition and Explosives
- Liquid Rocket Propellants