Combustion of the solid propellant with addition of aluminum powder under an acceleration load

The paper presents a physical-mathematical model for the metallized solid propellant combustion under an acceleration load directed normally to the burning surface. The model takes into account the thermal effect of decomposition of the condensed phase, convection, diffusion, the exothermic chemical reaction in a gas phase, heating and combustion of Al particles in the gas flow, the flow of combustion products, the velocity lag of the particles in relation to the gas, and the acceleration field effect on the motion of Al particles. The effect of the size and mass fraction of Al particles emitted from the burning surface on the combustion rate is also taken into consideration. The impact of the size of Al particles emitted from the burning surface, on the linear burning rate has been investigated under an acceleration load. The research results showed that the combustion rate increased with increasing acceleration load. It was also revealed that the larger the size of aluminum particles emitted from the burning surface, the higher the response of the combustion rate to the acceleration load. The results showed that increasing mass fraction of aluminum in the propellant composition led to an increase in the response of the relative combustion rate. It was also found that the relative combustion rate sensitivity increased with an increase in pressure above the burning surface. The results obtained are in a qualitative agreement with those described in the scientific literature.