Combustion Model for a Composite Solid Propellant with an Evaporating Coolant

This paper presents a combustion model for a solid propellant consisting of a matrix capable of self-sustained combustion and particles of a polydisperse coolant distributed in it. Heat transfer between the exothermically decomposing matrix and coolant particles in the condensed phase and the gas-phase products of their gasification. The leading reaction in the region of the matrix and the coolant evaporation surface are assumed to be located at the interface. The heat consumption for coolant evaporation is determined by the depth of coolant gasification during passage through the interface, which depends on the coolant particle size and the propellant burning rate. Parametric identification of the model was carried out using the results of sieve analysis of the coolant particle size distribution and an experimental dependence of the burning rate on pressure. It is shown that the model can be used to predict and provide the required ballistic performance of the propellant during its development and series production.