Exploratory research on active cooling of SRM by means of liquid injection

Exploratory research on active cooling of SRM by means of liquid injection was carried out to find out the new ways for thermal protection of SRM. A set of active cooling test system with liquid injection was built. The principle test was carried out. Water was chosen as coolant, which injected along the inner surface of convergence section. The temperatures of inner surface and external surface were measured. The experiment results show that introduction of coolant lowers the temperature of inner surface greatly, but may cause certain specific impulse loss. Because the coolant takes part in doing work, the thrust increases. Calculation model for property of SRM with liquid injection was derived and validated by the experiment results. The empirical formula on cooling efficiency was obtained by means of the experiment.