关键词: 固体推进剂火箭发动机;喷管;故障分析

Abstract: According to the fault in ground tests of flame-leak of nozzle of a large solid rocket motor, a series of simulation tests cheking the fault has been carried out. Firstly, small flame-leak taking place at the rear side wall of the nozzle in middle period of testing has been checked by simulation tests. The test results demonstrate that if there are side holes in the middle and rear side wall of divergent section of nozzle, flame-leak can not happen by the effect of local static pressure only. However if there are any resistant part in gas flow against the hole, making the local gas flow partly stagnated, the flame-leak takes place at this hole affirmly although the local static pressure is very low. Besides the simulation tests, analytical calculations have been made in accordance with the principle of flame-leak.Other simulation tests have been made in order to check the flame-lake taking place several times in the forehead of divergent section of prototype nozzle. The tests demonstrated that if there is any hole punched by burning erosion at the forehead of divergent section of the nozzle, the flame scurries off from the hole by effect of local static pressure only, so long as the local wall of nozzle is not thickenough.

Key words: Solid propellant rocket engine;Nozzle;Fault analysis