A model for the deflagration of aqueous solutions of hydroxylammonium nitrate

Abstract

Deflagration theory of the type that has achieved success for describing burning rates of ammonium perchlorate and nitramine propellants is applied to aqueous solutions of hydroxyl-ammonium nitrate (HAN). The theory considers the chemical kinetics, energetics and fluid dynamics of the combustion zone, making use of asymptotic analysis to decide what combustion mechanisms are consistent with available data. The model is used in conjunction with experimental results to obtain frequency factors and overall activation energies for HAN decomposition. Results suggest that deflagration rates are controlled by condensed-phase combustion with production of water dominating the heat release and that phase and chemical equilibrium are not approached in the condensed-phase combustion zone. The results also support the postulate that the rate of HAN decomposition is controlled by the rate of proton transfer from NH 3 OH + to NO 3 − . Theoretical predictions of deflagration rates compare favorably with experimental data.