Research on the 1∶2 Subharmonic Resonance and Bifurcation of the Nonlinear Rotor-Seal System
-
摘要: 研究了转子-密封系统在气流激振力作用下的低频振动——1∶2亚谐共振现象.利用流体计算动力学(CFD)方法对转子-密封系统进行了流场模拟计算,辨识出适用于气流流场的Muszynska模型参数,并建立了转子-密封系统动力学方程.采用多尺度方法将系统进行3次截断,并得到系统响应.采用奇异性理论研究了系统的1∶2亚谐共振,进一步得到系统亚谐共振的分岔方程和转迁集,根据转迁集给出了在不同奇异性参数空间内的分岔图.同时,由分岔方程得到了亚谐共振非零解存在的条件.其分析结果对抑制转子-密封系统的亚谐振动有重要的工程意义.Abstract: The 1∶2 subharmonic resonance of the labyrinth seals/rotor systems was investigated, which the low-frequency vibration of stream turbines could be caused by the gas exciting force in. The empirical parameters of gas exciting force of Muszynska model were obtained by using the results of Computational Fluid Dynamics (CFD). Based on multiple scale method, the 1∶2 subharmonic resonance response of the dynamic system was gained by truncating the system with three orders. The transition sets and the local bifurcations diagrams of the dynamics system were presented by employing singular theory analysis. Meanwhile, the existence conditions of subharmonic resonance non-zeros solutions of the dynamic system were obtained,which provides a new theoretical basis in recognizing and protecting the rotor from the subharmonic resonant failures in the turbine machinery.
-
Key words:
- rotor-seal /
- 1∶2 subharmonic resonance /
- flow field computation /
- gas flow exciting force /
- singularity
-
[1] Dimarogonas A D, Gomez-Mancilla J C. Flow-excited turbine rotor instability[J]. International Journal of Rotating Machinery, 1994, 1(1): 37-51. [2] Marquette O R, Childs D W, San Andres L. Eccentricity effects on the rotordynamic coefficients of plain annular seals theory versus experiment[J]. ASME Journal of Tribology, 1997, 119(3): 443-447. [3] Klaus Kwanka. Dynamic coefficients of stepped labyrinth gas seals[J]. Journal of Engineering for Gas Turbines and Power, 2000, 122(3): 473-477. [4] Dietzed F J, Nordmann R. Calculating rotordynamic coefficients of seals by finite-difference techniques[J]. ASME Journal of Tribology, 1987, 109(3): 388-394. [5] Toshio H, GUO Zeng-lin, Gordon K R. Application of computational fluid dynamics analysis for rotating machinery—partⅡ: labyrinth seal analysis[J]. Journal of Engineering for Gas Turbine and Power, 2005, 127(4): 820-826. [6] Alford J S. Protecting turbo-machinery from self-excited whirl[J]. ASME Journal of Engineering for Power, 1956, 87(4): 333-344. [7] Rosenberg S S.Investigating aerodynamics transverse forces in labyrinth seals in cases involving rotor eccentricity[J].Energomashinostrojenie, l974, 8(8): 15-17. [8] Muszynska A. Whirl and whip rotor-bearing stability problems[J]. Journal of Sound and Vibration, 1986, 110(3): 443-462. [9] Ding Q, Cooper J E, Leung A Y T. Hopf bifurcation analysis of a rotor/seal system[J]. Journal of Sound and Vibration, 2002, 252(5): 817-833. [10] 刘晓锋, 陆颂元. 迷宫密封转子动特性三维CFD数值的研究[J].热能动力工程, 2006, 21(6): 635-639.(LIU Xiao-feng; LU Song-yuan. A Study of methods used for three-dimensional CFD (computational fluid dynamics) numerical analysis of dynamic characteristics of rotors with labyrinth seals[J]. Journal of Engineering for Thermal Energy and Power, 2006, 21(6): 635-639.(in Chinese)) [11] Childs D W. Dynamic analysis of turbulent annular seals based on hirs lubrication equation[J].Journal of Lubrication Technology, 1983, 105(3): 429-436. [12] Golubistky M, Schaeffer D G. Singularities and Groups in Bifurcation Theory[M]. Vol Ⅰ, New York: Springer-Verlag, 1985.
点击查看大图
计量
- 文章访问数: 1297
- HTML全文浏览量: 91
- PDF下载量: 798
- 被引次数: 0