氢氧推力室再生冷却内壁故障分析

对某氢氧火箭发动机在热试车后推力室再生冷却通道内壁产生裂纹的故障建立了理论分析模型,并进行了温度场与应力场的耦合计算分析。分析认为,推力室内壁在连续的发动机热试车中出现故障的机理为较大的热载荷和机械载荷的组合促使推力室内壁的组合应力超过当地的屈服极限,产生较大的塑性变形所致。采用改善冷却通道的结构形式、燃烧室内壁采用适当厚度的隔热镀层、降低推力室内壁应力比R等措施可以提高再生冷却推力室的热循环寿命。

Failure analysis on regeneratively cooled wall of a hydrogen-oxygen thrust chamber

After the hot fire test of a hydrogen-oxygen rocket engine, the dog house effect and typical failure happened on the combustion chamber inner wall. The analyzing model for the failurewas built and numerical work of couplings between thermal and mechanical fields was done. The result showed that the failure was basically because the large thermal and mechanical loading led to huge local yield stress of the combustion chamber wall and the large plastic deformation on the combustion chamber wall. By optimizing regeneratively cooled structure, adopting appropriate thickness of the thermal insulation plate layer, reducing the stress ratio of interior wall etc, the hot cycle life of regeneratively cooled combustion chamber.