Study On Problems Related To The Ignition Process Of Solid Rocket Motor

The study on the flow mechanism and the factors influencing of ignition of SRM has great meaning in the application field, for the reason that faults occur easily in the ignition process of solid rocket motor. Two problems about ignition presented in this paper were discussed as follows:Nonlinear unsteady flow in the initial ignition process in combustor of solid rocket motor with finocyl grain is simulated numerically. Igniting pressurization process in solid rocket motor and the instantaneous impact induced by the inflow on the propellant grain during ignition process is studied in the present paper. At the same time, the instantaneous impact, which are varied with r_ig/R_p (the igniter exit ratio to the solid rocket motorchannel radius) and pressure of the igniter exit is compared and analyzed. Instantaneous wave structures of jet and load on the grain are gained. The simulation results show that pressure-rise velocity increases sharply caused by wave structure of igniter jet flow; the dynamic load which induced by strain rate on the surface of grain is great and varies with the position of the wall in grain. The ratio of the maximum pressure on the fixed location position on the surface of the grain to the radius of the igniter exit is a linear relationship.In the engineering application, the ignition transient process of the large aspect ratio SRM with cylindrical grain was numerically simulated in this paper. According to the pressure history curve calculated, classical phases of the pressure evolution and pressure-rise velocity in different phases at the initial ignition process was quantitative analyzed. The effects on the pressure history curve of design parameters including the velocity of flame propagation, opening pressure of nozzle closure, the igniter flow rate, propellant burning rate and the radius of nozzle on the ignition pressurization course of motor are reviewed.