Numerical Study on the Combustion of NEPE Sandwich Propellant in Depressurization Environment

Abstract In this paper, a two-dimensional sandwich model is proposed to simulate the combustion characteristics and combustion instability mechanism of NEPE propellant in depressurization environment. In order to explain the combustion process of the propellant, a complex kinetic reaction mechanism is introduced. The interaction between the condensed phase and gas phase is treated by using the source term method. The final results show that the dominant factor controlling the reaction during the depressurization process changes from diffusion mixing to chemical reaction, with a concomitant reduction in the thermal feedback from the flame to the combustion surface and an increase in heat storage inside the propellant. These two thermal effects reduce the heat available for the thermal decomposition of the solid phase, making combustion less efficient.