补燃发动机总体布局动态设计研究

Dynamic design research of staged-combustion engine overall layout

基于经典的振动理论,结合现代的有限元分析方法,研究了补燃火箭发动机整机结构以及主要管路的固有频率和振型,进行了整机结构中的Y形管模态试验,并分析了真实发动机试车时的主导振动频率。结果表明,Y形管的计算固有频率和试验固有频率相符,振型一致;管路系统的固有频率高于发动机整机的固有频率;发动机试车时的主导振动频率与其固有特性不相耦合。模态计算和试验结果表明,该发动机总体布局结构在动态特性上是合理的。

Based on fundamental vibration theories, the natural frequencies and mode shapes of the entire staged-combustion rocket engine and the engine＇s main pipeline system were investigated with modern finite element analysis method. The modal test of Y-shape-pipe on the entire structure was carried out and coupling resonance frequencies of the actual entire engine were also analyzed during operation. The results show that computational natural frequencies and mode shapes of Y-shape pipe are consistent with experimental natural frequencies and mode shapes, the lowest natural frequency of the pipeline system is higher than the lowest natural frequency of the entire structure, and the coupling resonance of the entire engine and the natural characteristics can not happen during operation. These results of the modal computations and modal tests indicate that overall layout of the entire engine structure is obviously reasonable for the dynamic characteristics.