摘要
以25 tf级膨胀循环氢氧发动机氢涡轮泵为研究对象,针对超高转速氢涡轮泵柔性转子临界转速设计、稳定性控制的难题,采用有限元方法建立转子轴承系统动力学模型,考虑支承结构参与振动、密封流体的刚度及阻尼、支承刚度及阻尼随转速变化等因素的影响,计算分析了设计参数对转子临界转速、稳定性的影响,提出了优化改进方向。仿真分析表明:该氢涡轮泵的转子系统设计方案能够满足临界转速裕度、弯曲应变能控制的设计准则和目标要求;工作转速范围内转子一阶对数衰减率最小值约为0.15,满足稳定性设计准则的最低要求;若要进一步提高转子的稳定性裕度,可适当降低泵端弹性支承刚度,把转子悬臂段的流体密封由齿型结构改为阻尼更大的孔型结构,将对数衰减率提高到0.22以上。
This paper concerns the design of rotor dynamic characteristics of an ultrahigh speed hydrogen turbopump for a 25 tf expander cycle engine.The dynamic model of the rotor-bearing system was established using finite element method.The influence of design parameters on the critical speeds and stability of the rotor was calculated and analyzed,considering the effects of vibration of supporting structure,fluid forces of seals and variation of supporting stiffness and damping coefficients with rotational speed,etc.Some improvement measures for the rotor system were put forward.The results show that the presented design scheme of the turbopump rotor system can meet the rotor critical speed and bending strain energy rate design criteria,and the initial design objectives.The minimum first-order logarithmic decrement of the rotor in the working speed range is about 0.15,which achieves the minimum standard for rotor stability design criteria.According to the test experiences of other turbopumps,measures should be taken to increase the logarithmic decrements to more than 0.22.It is suggested that the stiffness of the elastic supporter at the pump end should be weakened properly,and the fluid seals in the cantilever section of the rotor should be redesigned from a tooth-shaped structure to a more damped orifice structure,so as to further improve the stability margin of the rotor.
作者
杜家磊
王怡萱
李铭
姜绪强
褚宝鑫
DU Jialei;WANG Yixuan;LI Ming;JIANG Xuqiang;CHU Baoxin(Beijing Aerospace Propulsion Institute, Beijing 100076, China)
出处
《火箭推进》
CAS
2022年第2期86-93,共8页
Journal of Rocket Propulsion
关键词
氢涡轮泵
柔性转子
转子动力学
临界转速
稳定性
hydrogen turbopump
flexible rotor
rotor dynamics
critical speed
stability
