EXPERIMENTAL-STUDY ON LIQUID QUENCH OF SOLID ROCKET MOTOR

This article proposes a physical model for liquid quench of solid rock et motor and presents the results of experimental study. It is found t hat there is a critical value of injection pressure drop during liquid quench of solid rocket motor. The critical value of injection pressur e drop increases with propellant energy (Q(f)). The additive selected appropriately added in liquid is able to reduce significantly the liqu id quantity required (LQR) Ws, for extinction of solid rocket motor. L QR reduced by the addition of 0.5% CE by weight in water are about 35 and 25% for double base propellant and nonmetalized polyurethane-ammon ium perchlorate composite propellant, respectively. LQR is mainly depe ndent upon the propellant energy, i.e., it increases with increasing p ropellant energy. For pure water, Ws is-proportional-to 0.1Q(f) and fo r water + 0.5% CE, Ws is-proportional-to 0.76Q(f). The variation of LQ R with the chamber pressure is related to pressure exponent of propell ant (n). If n > 0, it increases with increasing chamber pressure; and if n < 0, it decreases with increasing chamber pressure. With the inje ction pressure drop increasing, LQR decreases and the depressurization rate of solid rocket motor increases, respectively. The experimental results and the analysis indicate that the theoretical study on liquid quench of solid rocket motor should include the coupling effects of t ransient burning of propellant, heat transfer of liquid jet impinged o n burning surface, evaporation of liquid droplets, and internal ballis tics of rocket motor.