非线性转子-密封系统稳定性与分岔

Study on the stability and bifurcation of nonlinear rotor-seal system

对单盘转子密封系统的分岔特性进行了研究,利用快速Galerkin方法和Floquet理论得到了转子密封系统的分岔转迁集,并分析了转子不平衡量、密封间隙以及密封两侧压差对系统分岔特性的影响,结果表明转子系统在密封流体作用下存在倍周期和Hopf分岔.最后通过数值仿真验证了所求得的分岔转迁集的正确性.研究结果为控制转子系统的稳定性提供了理论依据.

The bifurcations of a rigid rotor-seal system were studied in a relatively wide parameter range. The transition boundaries of the system were obtained and the effect of the degree of rotor imbalance, clearance of the seal and the pressure drop of the flow in the seal on the bifurcations characteristics of the system was analyzed with fast Galerkin method in combination with Floquet theory. The result shows that the rotor system may undergo period doubling or Hopf bifurcations caused by the fluid-induced vibration. In some typical parameter ranges, the bifurcation diagrams of the rotor-seal system are acquired with numerical integral method. The simulation result verifies the correctness of the transition boundaries. The result provides the theoretical base for qualitatively controlling the stable operating state of rotors.