Rotor dynamic characteristics of bearing-rotor system of turbo charged pump
PAN Huishan1, JIANG Xiaoping1, 2*, LANG Tao1, ZHOU Chenjia1, CAO Ling1, ZHANG Desheng1, HU Jingning1
1. National Research Center of Pumps, Jiangsu University, Zhenjiang, Jiangsu 212013, China; 2. National Engineering and Technology Center for Information Agriculture, Nanjing, Jiangsu 210095, China
Abstract：In response to the problem of high-speed operation stability of turbo charged pump, the water-lubricated bearing-rotor system was taken as the research object, the characteristic coefficients of the bearings were obtained through bearing modeling and Matlab programming calculation, and the physical model and finite element model of the bearing-rotor system were established; the first 4th order critical speed and mode shapes of the rotor system were calculated by Samcef Rotor; the internal flow field of turbo charger pump was calculated by CFX14.5, and the radial force of the turbine impeller and the booster pump impeller under different flow conditions were obtained, the transient response analysis of bearing-rotor system was conducted by using the unbalanced mass and radial force as external excitation. The results show that the critical speed of the first-stage bending of the rotor system is 36 298 r/min, which is much larger than the design speed of 16 000 r/min, indicating that the rotor of the turbo charged pump is a rigid rotor. Compared with the pump, the transient response of the turbine is more obvious and the amplitude is larger by only using unbalanced mass as an external incentive. When loading fluid excitation force at the same time, the vibration is significantly strengthened. The amplitude of the vibration displacement is different under different flow conditions, and the rotor system is most stable under design flow conditions.
