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 characteristi cs of torsional vibration of a rotor with rotor-to-stator rub an studied. I t can be concluded that the measured natural torsional frequency (f(rub)) w ith rub is higher than the one (f(ori)) without rub. When rub happens, if t he rotating frequency is higher than f(rub), torsional vibrations with a me asured natural torsional frequency (f(rub)) and 1x, 2x are excited; if the rotating frequency is between f(rub) and f(ori), the torsional vibration wh ich is so called resonance (one-time rotating frequency) is excited; if the rotating frequency is lower than f(ori), torsional vibrations with one-tim e rotating frequency and f(rub) are excited, and a small torsional vibratio n with 2x is excited too. (C) 2000 Elsevier Science Ltd. All rights reserve d.