Experiment on the characteristics of torsional vibration of rotor-to-stator rub in turbomachinery

By use of the DK-II torsional vibration measuring system, the characteristics of torsional vibration of a rotor with rotor-to-stator rub are studied. It can be concluded that the measured natural torsional frequency (frub) with rub is higher than the one (fori) without rub. When rub happens, if the rotating frequency is higher than frub, torsional vibrations with a measured natural torsional frequency (frub) and 1×, 2× are excited; if the rotating frequency is between frub and fori, the torsional vibration which is so called resonance (one-time rotating frequency) is excited; if the rotating frequency is lower than fori, torsional vibrations with one-time rotating frequency and frub are excited, and a small torsional vibration with 2× is excited too.