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

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