Stability and bifurcation of unbalance rotor/labyrinth seal system

The influence of labyrinth seal on the stability of unbalanced rotor system was presented. Under the periodic excitation of rotor unbalance, the whirling vibration of rotor is synchronous if the rotation speed is below stability threshold, whereas the vibration becomes severe and asynchronous which is defined as unstable if the rotation speed exceeds threshold. The Muszynska model of seal force and shooting method were used to investigate synchronous solution of the dynamic equation of rotor system. Then, based on Floquet theory the stability of synchronous solution and unstable dynamic characteristic of system were analyzed.