大推力液体火箭发动机结构中的力学问题

依据大推力液体火箭发动机工作时极端的力热环境状态, 阐述分析了大推力发动机强振动、大静载、多源激励和传递路径复杂的力学特点. 静力学方面介绍了整机结构载荷分析和组件静力学分析方法, 动力学方面介绍了整机低频模型、精细化动力学修正、多源载荷等效等问题的研究情况. 针对发动机典型的部件, 梳理了大推力发动机研制中面临的力学挑战, 包括高温高压燃气摇摆装置、转子动力学、动静干涉流体激振、诱导轮汽蚀振荡、大范围轴向力平衡、超音速涡轮颤振、推力室热疲劳、喷管侧向力载荷、总装管路疲劳断裂等问题, 指出了力学需求和未来研究方向. 最后对发动机结构概率失效分析的现状进行了简要介绍, 为大推力液体火箭发动机研制提供力学支撑. 

Mechanical problems of the large thrust liquid rocket engine

According to the extreme mechanical and thermal environment of high-thrust rocket engines, the mechanical characteristics of high thrust liquid rocket engines, such as strong vibration, large static load, multi-source excitation, and complex load transfer path, are analyzed. In statics, the whole engine structural load analysis and the components static analysis method are introduced. In dynamics, the low-frequency structural dynamic model of the entire engine, the refined model updating technique and multi-source load equivalent method are introduced. For the typical engine components, the mechanical challenges faced in the development of high thrust engine are summarized, including high-temperature and high-pressure gas swing device, rotor dynamics, dynamic and static interference fluid excitation, cavitation oscillation in inducer, large range axial force balance, supersonic turbine aeroelastic, thrust chamber thermal fatigue, nozzle lateral force load, assembly pipeline fatigue fracture, etc. The mechanical requirements and future research directions are pointed out. Finally, the status of probabilistic failure analysis of the engine is briefly introduced, which provides mechanical support for the development of high-thrust liquid rocket engines.