Research for nonlinear vibration characteristics of sealing structure rub-impact between dual-rotor shafts

Abstract In order to study the influence of sealing structure rub-impact between dual-rotor shafts on nonlinear vibration, a dynamic model of an aero-engine dual-rotor system with sealing structure rub-impact between dual-rotor shafts in consideration was established. The nonlinear vibration phenomenon caused by the rubbing of the sealing structure between dual-rotor shafts was investigated through simulation and experimentation. The result shows that the backward whirling natural frequency of the dual-rotor system will be induced by the sealing structure rub-impact between dual-rotor shafts, which is shown as a frequency curve not directly related to the rotating speeds of high/low-pressure rotors in the waterfall diagram. Above the critical speed, the vibration will increase continuously with the increase of rotating speed, which will be detrimental to the aero-engine.