Mathematical simulation of transient combustion of melted energetic materials

Abstract

The computer code is elaborated for numerical simulation of transient combustion of energetic materials (EM) subjected to the action of time-dependent heat flux and under transient pressure conditions. It allows studying combustion response upon interrupted irradiation (transient pressure) and under action of periodically varied heat flux (pressure) in order to determine stability of ignition transients and parameters of transient combustion. The originally solid EM melts and then evaporates at the surface. It is assumed that chemical transformations occur both in the condensed and gas phases. At the burning surface, the phase transition condition in the form of Clapeyron-Clausius law for equilibrium evaporation is formulated that corresponds to the case of combustion of sublimated or melted EM. The paper contains description of transient combustion problem formulation and several examples of transient combustion modeling. At present time a precise prediction of transient burning rate characteristics is impossible because of the lack of information about magnitude of EM parameters at high temperatures. However, the simulation results bring valuable qualitative information about burning rate behavior at variations in time of external conditions – radiant flux and pressure.