Rotor-to-stator rub causing spiral vibrations - modelling and validation of experimental data on a real rotating machine

摘要

The model presented in this paper for the analysis of the spiral vibrations has the unusual characteristic in that it allows real machines to be analysed, since it uses a fully assembled machine model (rotor, bearings and foundation) and implements a rather sophisticated thermal and contact model. The conditions that lead to spirals that have a self-propagating trend and cause the system to be unstable or conversely the conditions of self-correcting trend that leads to system stability can be analysed. The experimental validation of the proposed model is performed on data coming from the generator of a 50 MW combined cycle power plant, in which unstable spiral vibration was observed at the operating speed during a power increasing.