The stiffness and damping coefficients of journal bearing are important parameters that affect the dynamic characteristics of rotor system. The multiplefrequency elliptical orbits whirl model based on twophase flow theory was established by the unsteady solution and mesh deformation method. On the basis of verifying the accuracy of solution model, we studied oil film pressure distribution features of singlephase flow and two phase flow, the change of the oil film force in the whirl orbits of the journal, and the influence of the whirling frequencies and eccentricity ratio on the stability of rotor system. The results show that only if two unsteady computations are needed, the rotordynamic coefficients of journal bearing can be obtained by the multiplefrequency elliptical orbits whirl model, which enhances analysis efficiency. Oil film force produced by the whirl motion changes with the variation of the whirl frequency of the journal, and the frequency of the oil film force is the same as that of the whirl motion of the journal. It is necessary to consider the whirl frequency when the rotordynamic characteristics and the stability of journal bearing are studied. The larger the eccentricity ratio of the journal, the greater the absolute value of the negative work of the oil film force, the faster the rotor whirling energy is consumed, the better the rotor stability.
SUN Dan,LI Sheng-Yuan-*,AI Yan-Ting et al. Dynamic characteristics of journal bearing and stability of rotor system based on work of oil film force[J]. Journal of Drainage and Irrigation Machinery Engin, 2019, 37(8): 699-704.
YE Xiaoyan,FENG Yaoning,WANG Jing,et al.Test and analysis of water-lubricated bearing of seawater desalination pumb [J].Journal of drainage and irrigation machinery engineering,2015,33(6):510-515.(in Chinese)
GUO Z, HIRANO T, KIRK R G. Application of CFD analysis for rotating machinery—part I: hydrodynamic, hydrostatic bearings and squeeze film damper[C]//ASME Turbo Expo 2003, Collocated With the 2003 International Joint Power Generation Conference, 2003.
GAO G, YIN Z, JIANG D, et al. Numerical analysis of plain journal bearing under hydrodynamic lubrication by water[J]. Tribology international, 2014, 75: 31-38.
XIONG Wanli, HOU Zhiquan, LYU Liang, et al. Method for calculating stiffness and damping coefficients of hybrid bearings based on dynamic mesh model[J]. Journal of mechanical engineering, 2012, 48(23): 118-126.(in Chinese)
LI Qiang, XU Weiwei, WANG Zhenbo, et al. Nume-rical calculation method of dynamic characteristics of journal bearing [J]. Journal of China University of Petroleum(natural science edition), 2014, 38(5): 165- 171.(in Chinese)
GELLER M, SCHEMMANN C, KLUCK N. Simulation of radial journal bearings using the FSI approach and a multi-phase model with integrated cavitation[J]. Progress in computational fluid dynamics an international journal, 2014, 14(1): 14-23.
HAGEMANN T, SCHWARZE H. A Theoretical study on frequency effects on tilting-pad journal bearing dynamic coefficients[C]//Proceedings of the 9th IFToMM International Conference on Rotor Dynamics. Springer International Publishing, 2015.
WILKES J C, CHILDS D W. Tilting pad journal bearings—A discussion on stability calculation, fre-quency dependence, and pad and pivot[J]. Journal of engineering for gas turbines & power, 2012, 134(12): 67-75.
CHENG F, JI W. A velocity-slip model for analysis of the fluid film in the cavitation region of a journal bearing[J]. Tribology international, 2016, 97: 163-172.
SUN Dan, WANG Shuang, WANG Keming, et al. CFD numerical analysis for dynamic characteristics of elliptical bearing and cylindrical bearing[J]. Noise and vibration control, 2015, 35(4): 1-5.(in Chinese)
LI Z, LI J, FENG Z. Comparisons of rotordynamic characteristics predictions for annular gas seals using the transient computational fluid dynamic method based on different single-frequency and multifrequency rotor whirling models[J]. Journal of tribology, 2016, 138(1): 011701.
DHANDE D Y,PANDE D W.Multiphase Flow analysis of hydrodynamic journal bearing using CFD coupled fluid structure interaction considering cavitation[J].Journal of king saud university-engineering sciences,2016(9): 1-10.