Abstract: To understand the failure mechanism, locate the failure position and predict the cyclic number of regeneratively cooled liquid rocket engine thrust chamber inner wall, fluid-thermo-structural numerical simulation was carried out for the thrust chamber. The fluid-thermal coupling analysis simulated the conjugate heat transfer process of regenerative cooling and provided the thermal and mechanical loading to the thermo-structural analysis. For thermo-structural analysis, a 3D analysis of the nonlinear deformation of the thrust chamber wall was performed. Through computation, the stress and strain distribution of thrust chamber inner wall at different stage of each cycle and the deformation process under cyclic loading were obtained, a post processing method was applied to predict the cyclic number of the thrust chamber inner wall when failure occured. The results show that the cyclic thermal and mechanical loading cause the inner wall to bulge and thin,and cooling channel located at upstream of the throat fails at first.

Key words: Liquid rocket engine; Thrust chamber; Fluid-structural coupling; Cyclic loading; Elasto-plastic material; Nonlinear structural analysis

摘要： 为了分析再生冷却式液体火箭发动机推力室内壁失效机理、判断失效位置及确定循环次数,对其进行流-热-固耦合计算。流-热耦合模拟推力室再生冷却耦合传热过程并为热-固耦合提供边界条件,热-固耦合对推力室壁在循环加载下的变形进行三维结构非线性分析。通过计算,得到了推力室壁在单循环各阶段和循环加载下的应力应变分布,对计算结果进行后处理,得到了推力室内壁失效时的循环次数。结果表明,推力室内壁在循环热和机械载荷作用下向推力室内鼓起和变薄,喉部上游冷却通道中心最先失效。 

关键词: 液体火箭发动机;推力室;流-固耦合;循环加载;弹塑性材料;非线性分析