浮环密封是引起轴系失稳的重要因素之一。本文建立浮环密封和转子瞬时运动关系，考虑温度影响，基于有限单元法求解瞬态流体动压力。利用摄动法求解锁死条件下浮环密封动力学系数，并与试验对比。结合非线性摩擦力和数值计算特点，提出浮环锁死动力学条件。建立浮环和转子耦合动力学模型，考虑瞬态流体动压力和摩擦力，研究浮环运动机理及相关因素。结果表明在小偏心率条件下，浮环负交叉刚度远大于主刚度；摩擦力越小、转速越高，锁死位置偏心率越小；锁死位置偏心较小时，浮环密封易引发轴系半频失稳现象，与工程实际相符合。
Abstract
Floating ring seals are an important factor causing rotors unstable. Establishing floating ring seals and rotor transient motion relation, transient hydrodynamic pressure is obtained by FEM, considering thermal effect. Dynamic coefficients are obtained by perturbation method when the seals are locked up and compared with test results. Basing on characteristics of nonlinear friction and numerical calculation, kinetic condition for locked-up of the seals is proposed. Floating ring seals and rotor coupled transient dynamics model is established, taking transient hydrodynamic pressure and friction into consideration, to study movement of the seals and relative factors. The predictions show that under conditions of small eccentricity, the negative cross stiffness is much greater than the direct; the smaller friction and the higher rotor speed are, the smaller eccentricity of locked-up position is; floating ring seals locked at small eccentricity can cause oil-whip instability phenomena in accord with engineering experience.
关键词
浮环密封 /
稳定性 /
瞬态响应 /
转子动力学
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Key words
floating ring seals /
stability /
transient response /
rotor dynamic
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参考文献
[1] Kirk,R.G.Oil seal dynamics:considerations for analysis of centrifugal compressor[C].Proceedings of the 15th Texas A&M Turbomachinery Symposium, Kansas: Texas A&M University, 1986. 25-34
[2] Julio E. Semanate，Luis San Andres．Analysis of multi-land high pressure oil seals[J]．S T L E Tribology Transactions．1993，36(4): 661-669
[3] Luis San Andres，Adolfo Delgado．A novel bulk-flow model for improved predictions of force coefficients in grooved oil seals operating eccentrically[J]．Journal of Engineering for Gas Turbines and Power. 2012, 134(5):0525091-05250910
[4] S.K.Baheti,R.G.Kirk．Finite element thermohydrodynamic analysis of a circumferentially grooved floating oil ring seal[J]．S T L E Tribology Transactions. 1995, 38(1): 86-96
[5] R. Gordon Kirk，S. K. Baheti．Evaluation of floating ring seals for centrifugal compressors using the finite element method[J]．Journal of Vibration and Acoustics, Transactions of the ASME. 1999, 121(1): 131-136
[6] S. K. Baheti，R. G. Kirk．Analysis of high pressure liquid seal ring distortion and stability using finite element methods[J]．J. Tribol.-Trans. ASME. 1999, 121(4): 921-926
[7] Dara W. Childs，Luis E. Rodriguez，Vito Cullotta，et al．Rotordynamic-coefficients and static (equilibrium loci and leakage) characteristics for short, laminar-flow annular seals[J].Journal of Tribology. 2006, 128(2): 378-387
[8] Dara W. Childs，Matthew Graviss，Luis E. Rodriguez．Influence of Groove Size on the Static and Rotordynamic Characteristics of Short, Laminar-Flow Annular Seals[J]．Journal of Tribology. 2007, 129(2): 398-406
[9] Tae-Woong Ha，Yong-Bok Lee，Chang-Ho Kim．Leakage and rotordynamic analysis of a high pressure floating ring seal in the turbo pump unit of a liquid rocket engine[J]. Tribology International, 2002, 35(3): 153-161
[10] 夏鹏．圆柱滑动轴承动静态特性分析及计算软件开发[D]．哈尔滨：哈尔滨工业大学，2013.
Xia Peng. Research on static and dynamic characteristics of plain journal bearing and development of analysis software [D]. Harbin:Harbin Institute of Technology, 2013.
[11] E. J. Berger．Friction modeling for dynamic system simulation[J]．Applied Mechanics Reviews.2002,55(6):535-577
[12] Matthew Sheridan Graviss. the Influence of a central groove on static and dynamic characteristics of an annular liquid seal with laminar flow[D]. Kansas: Texas A&M University, 2005
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