某火箭发动机的氢涡轮泵存在异常振动问题, 其原因是涡轮泵使用的迷宫密封对泵的转子系统稳定性产生了影响.为解决振动问题, 建立转子系统模型, 利用CFD软件获得密封和诱导轮动力特性系数, 代入转子系统模型后提取转子系统对数衰减率, 研究迷宫密封的各项参数和诱导轮对涡轮泵运行稳定性的影响规律, 并分析采用孔型阻尼密封代替迷宫密封对转子系统稳定性的影响.结果表明:对于迷宫密封, 采用较小的偏心率、较大的密封间隙、适宜齿厚和较多的齿数时, 转子系统可获得比较大的对数衰减率, 但仍不满足API617标准中对数衰减率大于0.1的要求, 而采用孔型阻尼密封代替迷宫密封能满足API617标准的要求, 大大提高了转子系统的运行稳定性.同时研究表明, 系统中的诱导轮对涡轮泵的稳定运行有负面影响.
An abnormal vibration problem exists in the hydrogen turbine pump in rocket engine, which is caused by the influence of the labyrinth seal used in the turbo pump on the stability of the pump's rotor system.In order to solve the vibration problem, the rotor system model was established.Dynamic coefficient of seal and inducer was calculated by CFD and was generated into the rotor system model to obtain rotor logarithmic decrement.The influence of labyrinth seal and inducer on the stability of rotor system was studied.The influence of hole-pattern seal instead of labyrinth seal on the stability of rotor system was analyzed.The results show that a relatively large rotor logarithmic decrement can be obtained by the labyrinth seal with small eccentricity, big sealing clearance, suitable tooth thickness and multiple teeth of labyrinth seal.However, it is still unable to meet the requirement of the logarithmic decay rate greater than 0.1 in API617 standard.The use of hole-pattern seal instead of labyrinth seal can meet the requirement of API617 standard, and the the stability of rotor system is improved greatly.The research also shows that the inducer has a negative effect for the stability of rotor system.