Numerical Simulation Of Combustion Process Of A Dual Thrust Solid Rocket Motor

For a long time,the research on the combustion mechanism of solid rocket motor propellant has been an important field of rocket engine research.At present,the research on solid rocket engine propellant combustion mainly concentrates the detailed propellant combustion mechanism and simplifies the establishment of model.At the same time,adding metal aluminum components in the solid propellant can produce positive and negative impact on the engine performance.In this paper,the steady-state combustion process of a dual thrust solid rocket motor model is studied.First of all,this paper makes a model verification of a detailed gas-phase reaction mechanism model and a simplified mechanism model,which are widely used by researchers.Secondly,the proven combustion simplification model is applied to the steady-state work of a dual thrust solid rocket motor.The influence of the different ratio of the oxidant AP and the binder HTPB on the flow field in the engine is studied.Finally,the effects of aluminum fractions containing different mass fraction on the flow field in the motor model were studied for the composite propellants containing metal aluminum components.At the same time,the AP / HTPB Composite propellant combustion were compared,and analyse the impact of aluminum components on the engine work.The results show that : In the steady-state combustion condition of the solid rocket motor,the pressure change of the flow field in the engine is only related to the density of the composite propellant,the characteristic speed,the burning speed coefficient,the pressure coefficient and the nozzle structure;The Mach number of the combustion chamber in the engine is close to zero,and the Mach number of the tail nozzle increases with the increase of the AP component of the composite propellant,and when the content of HTPB component reaches 10% or less,the Mach number of gas in the long tail nozzle decreases,and at the same time,when the aluminum component is added,the Mach number of the tail nozzle decreases with the increase of the aluminum content;The temperature of the flow field in the engine increases with the increase of the mass fraction of AP,and when the AP mass fraction ratio is greater than 80%,the engine flow field temperature is decreasing,and while adding aluminum components,the temperature of the flow field in the engine is gradually increasedwith the increase of the aluminum content;The addition of aluminum to the propellant enhances the combustion,but at the same time reduces the engine thrust efficiency.