水下涡轮机转子—滚动轴承非线性振动仿真

摘要

For the unbalanced bearing-rotor system, considering the nonlinear Hertzian contact force and the radial internal clearance of bearing, an nonlinear dynamic model is established. Using Rouge- Kutta-Felhberg of variational step, the nonlinear oscillation is simulated based on bifurcation and chaos theory. Analysis results indicate that: VC periodic oscillation is principal with low rotate speed; Enlargement rotate speed, quasi-period oscillation is showed under the effection of rotate frequency and VC frequency; With high rotate speed, the system would pass through fitful bifurcation to chaos. The analytic results provide the theoretical reference for designing the underwater turbine engine.%在考虑支承滚动轴承内部间隙、轴承非线性Hertz接触刚度及转子不平衡量的基础上,建立了水下涡轮机刚性水平转子系统的动力学模型;采用变步长的Rouge- Kutta- Felhberg方法对系统动力学模型进行了数值仿真,基于混沌与分岔理论分析了系统的非线性振动;研究表明,转速较低时,系统的响应以VC周期振动为主;提高转速,系统在旋转频率、VC频率的组合激励下,表现出拟周期振动;继续提高转速时,系统经历阵发性分岔进入混沌状态;研究结论对水下涡轮机系统设计具有重要意义.