非线性"转子-轴承-密封"系统动力分析

将非线性油膜力模型与密封流体Muszynska密封力模型相结合，建立了具有非线性转子-轴承-密封系统的动力学模型。针对转速等因素对耦合系统动态响应的影响进行了仿真计算，给出了系统响应随转子转速变化、压差变化和密封间隙变化的分叉图和最大Lyapunov指数曲线图，以及一些典型的Poincare截面图、轴心轨迹图和频谱图。数值仿真表明，非线性密封力抑制了系统出现倍周期分叉，并且该耦合系统呈现出复杂的动力学行为，产生了包括周期、倍周期和拟周期等丰富的振动现象。

Dynamic analysis of a rotor-bearing-seal nonlinear system

In the present paper, under the conditions that both the nonlinear bearing force and the seal force are nonlinear, the dynamic model of the nonlinear rotor-bearing-seal system was set up. By using the numerical value integral method, the influences of a series of factors on the nonlinear dynamic behaviors of the coupled system caused by seal forces were studied. By changing the values of the rotation speeds, the pressures and the seal clearances, the bifurcation diagram and the curves of maximal Lyapunov exponent were obtained respectively. Meanwhile the pictures of some typical Poincare maps, state trajectories and frequency spectra were also given. From the results of the numerical simulation, it is found that there are periodic motion, doubling-periodic motion, approximate-periodic motion and chaos motion in the coupled system.