椭圆轴承-转子系统的稳定性与分岔  

Stability and bifurcation of elliptic bearing-rotor systems

作　　者：王立刚 曹登庆[1] 王晋麟[1] 黄文虎[1] 崔颖[2] 

机构地区：[1]哈尔滨工业大学航天学院,哈尔滨150001 [2]哈尔滨工业大学能源科学与工程学院,哈尔滨150001

出　　处：《航空动力学报》2008年第2期263-269,共7页Journal of Aerospace Power

基　　金：国家自然科学基金重点项目(10632040)

摘　　要：针对200 MW汽轮发电机组轴系,建立了椭圆轴承-转子系统的动力学模型和椭圆轴承油膜力非线性模型.利用固定界面模态综合法将608个自由度的非线性动力学系统降至30个自由度,然后采用Rouge-Kutta法对降维后的模型进行数值求解,得到随转速变化的频响曲线、分岔图和三维谱图,并据此分析系统的稳定性.利用转速变化的频响曲线,分析了偏心距、润滑剂黏度系数和轴承长径比等参数对系统动力特性的影响.数值结果表明:椭圆轴承-转子系统的稳定性区域要大于圆轴承?转子系统的稳定性区域.The nonlinear dynamic behavior of elliptic bearing-rotor system was investigated by working on 200 MW steam turbine as an example. The finite element method was employed to establish a dynamical model of the system and a nonlinear model derived from the variational principle was adopted to describe the oil force of elliptic bearings. Then, the nonlinear dynamic system with 608-degree-of-freedom was reduced to a 30-degree-of-freeodm model in terms of the fixed interface mode synthesis method. The Rouge-Kutta method was employed to solve the reduced model numerically, and the frequency-response curve, the bifurcation diagram, and the three dimensional spectral plot obtained were used to analyze the stability of the rotor-bearing system. The effects, on the dynamic behavior of the system, of the eccentricity, the oil viscosity and the length-to-diameter ratio of bearing were discussed in terms of the frequency-response curve. The numerical results show that the stability range of the elliptic bearing-rotor model is larger than that of the circular bearing-rotor system.

关 键 词：航空、 航天推进系统 椭圆轴承 汽轮机 降维 非线性振动 油膜振荡 

分 类 号：TH133[机械工程—机械制造及自动化] O322[理学—一般力学与力学基础]