Investigation on the supplementary combustion scheme for the divergent section of a solid rocket engine nozzle

Abstract

The low combustion efficiency of the propellant results in the small specific impulse of the solid rocket engine. This paper attempts to install the inlet on the divergent section of the engine nozzle for additional combustion in order to improve the specific impulse of the solid rocket engine. In this paper, the external section, the throat and the divergent section of the inlet are designed by theoretical calculation, programming calculation and numerical simulation, and the inlet is installed on the nozzle to carry out the substantial integrated simulation. The obtained results show that there is a high temperature region upstream of the inlet, and the temperature rises sharply in this region. Severe combustion area appears downstream of the air entrance, along the axis direction and parallel to the nozzle wall. This is strip-shaped distribution. Without considering the resistance, the supplementary combustion for the divergent section of the solid rocket engine nozzle can effectively improve the specific impulse by about 20%.