不平衡转子涡动对鼓筒振动特性影响

Effect of unbalanced rotor whirl on drum vibration

针对叶轮机械中鼓盘式转子,考虑转子涡动与鼓筒振动间耦合作用,建立轮盘-鼓筒-转轴系统动力学模型,分析不平衡转子涡动对鼓筒振动特性影响。结果表明,不平衡转子涡动仅与环向波数为1的鼓筒弹性振动模态耦合;转轴支撑刚度为线性时,转子稳态运动轴心轨迹为圆形,不平衡转子涡动不直接引发鼓筒稳态弹性振动;转轴为非线性支撑时,转子稳态运动轴心轨迹变复杂,不平衡转子涡动会引起鼓筒小幅稳态振动。

Taking into account the coupling between rotor whirl and drum vibration, the dynamic model of a diskdrum-shaft system was established for the drum-disk type rotors in turbo-machines. Based on the model, the effect of unbalanced rotor whirl on drum vibration was studied. The results show that the unbalanced rotor whirl is coupled only with the drum vibration modes which carry one circumferential wavenumber. If the support stiffness of the shaft is linear, the centroid motion locus of the shaft will be a circle and the steady-state vibration of drum cannot be maintained. However, the centroid motion locus will be complex provided that the support stiffness of the shaft is nonlinear. Under this circumstance, slight and steady-state vibration of drum will be induced by the whirl of the unbalanced rotor.