关键词: 固体推进剂火箭发动机;喷管烧蚀;故障分析

Abstract: According to the failure of nozzle burned-through in a large solid rocket motor during ground tests, a series of diagnostic investigation has been carried out. Firstly, the derivative of radius of the nozzle contour along the axis of nozzle is analysed. It is found that, the discontinuity of exists at the joint point of contour curve’ Secondly, a set of comparative simulation tests for nozz1e contour is carried out. It is demonstrated that serious burning erosion occures behind discontinuous point of contour profile in the divergent section. However, burning erosion do not occurs completely in the divergent section without discontinuous point. By using the aeredynamic computation of prototype nozz1e, the eddy system is found in the area near the discontinous point of dirivative of contour profile in the divergent section. A modified contour design of nozzle contour is suggested in the paper. That is, the circular are is replaced by a cosine curve, the derivaction of which is continuous at the joint point of nozzle contour. Thus the nozzle burning-throught can be avoid.

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