Investigations of Chemical Nonequilibrium Two-Phase Flow in Solid Rocket Motor Nozzles

In this study, a calculation method for two-phase nonequilibrium flow in solid rocket motor nozzles is established, and an in-depth investigation into the nonequilibrium flow within the nozzle is conducted. Based on NEPE high-energy propellant, a simplified reaction mechanism model is established and validated using the full-component sensitivity analysis method for chemical nonequilibrium flow in the nozzle, consisting of 16 components and 22 steps. The nonequilibrium and frozen flow in the nozzle are simulated, and it is found that in nonequilibrium flow, the chemical reactions result in a 22.4% increase in the flow field temperature and an approximate 4.13% improvement in specific impulse. In addition, the impacts of different total pressure conditions on the nonequilibrium flow in the nozzle are studied, in which the increase in pressure enhances the overall temperature, but the change in velocity and Mach number are negligible. Finally, a discrete phase model is adopted in the nonequilibrium flow simulation to predict the evolution of aluminum oxide particles with different sizes within the nozzle. The results indicate that the presence of particles can enhance nozzle total thrust while reducing the specific impulse. As the particle size increases, both the nozzle thrust and specific impulse decrease, with the specific impulse being more significantly affected by particle size variations due to the variation in the gas-phase mass flow rate.