Predicted Post-thrust For The Upper-stage Solid Rocket Motor

One important factor that is directly connected with the precision of satellite is the post-thrust of the upper-stage solid rocket motor. An accurate prediction of post-thrust for solid motor is important for fixing the stage separation between the motor and the satellite and in the sound rocket separation system design. In this article numerical research are carried out to make us know the characteristics and magnitude of post-thrust.It is established that a physical model of the internal insulation. The structure of the solid rocket motor is changed to two dimensions. The molten slag (Al2O3) and the radiation from nozzle that are the major source of heat for the production of gases are used in the model. In order to studying the characteristics of charring and ablation of internal insulation, three-layer model is established.Numerical simulation includes mainly simulation of the internal insulation charring and ablation and simulation of the flow field. First, It is constructed that two dimension thermal condition equations and mass conservation equations and energy equations. They are solved by the explicit difference method. In the surface of insulation, we consider the thermo-chemical ablation not only between carbon and combustion gas but also between carbon and paralysis gas. It is investigated that the influences of concentration and velocity of particle on the erosion of insulation. Second, in combustion chamber, we construct one dimensions Euler equations which include mass source. These equations are solved by MacCormack formula. Moreover, since the special characteristics of post-stage, flow field is solved coupling with the charring and ablation of insulation.For the upper-stage solid rocket motor, by illustration checks and analyses, the feasibility and validity of the prediction about post-thrust has been validated.The researches in this thesis are of theoretical and practical significance for introducing the post-thrust at the phase of solid rocket motor concept design, and improving the design means.