Study on the solid propellant burning rate enhanced by plasma in the closed bomb

Abstract

Abstract A closed bomb experimental system is employed to discuss the ignition and combustion characteristics of the solid propellant with the capillary plasma generator (CPG). 4/7 high-nitrogen solid propellant, 5/7 high-graphite solid propellant and 5/7 low temperature sensitivity coated propellant are ignited in the closed bomb. Compared with the experimental results with the conventional ignition, the ignition delay time with the CPG is reduced and the burning process of the propellant is enhanced. The pressure changing rate is used to analyse the enhanced gas generation rate (EGGR) of the propellant with the plasma. Compared with the pressure changing rate with different igniters, the enhanced gas generation rate during electrical discharge (EGGRDED) is proved. When 4/7 high-nitrogen solid propellant and 5/7 low temperature sensitivity coated propellant are ignited in the closed bomb, the enhanced gas generation rate post electrical discharge (EGGRPED) appears. The EGGRPED is mainly influenced by the composition of the propellant. The influence of the electrical parameters of the CPG and the distance between the CPG and the solid propellant is studied by the closed bomb experiments. The ignition delay time and the burning time of the propellant reduce with the increasing of the electric power or the decreasing of the distance between the CPG and the propellant. Depending on the pressure changing rate in the closed bomb experiments, the EGGRDED increases with the increasing of the electric power or the decreasing of the distance between the CPG and the propellant, while the EGGRPED is not influenced by the electric power or the distance between the CPG and the propellant.