Accurate modelling of bearings and seals for rotating machines for power generation

This paper reviews the most recent achievements obtained in the modelling of oil-film bearings and of labyrinth seals at Politecnico di Milano. These two topics are receiving increasing interest in nowadays rotor dynamics, in particular by OEM, owing to the increasing demand of high-performances/efficiencies and to the remarkable effect that they have on the stability of rotating machinery. The precise evaluation of dynamic coefficients, for both oil-film tilting-pad journal bearings and labyrinth seals, allows reliable evaluation of machine stability in the design phase. At this aim, several models are available in the literature. On the contrary, there are not so many cases, in which the models are validated by means of experimental tests. The bearing and labyrinth seal models presented here are supported by experimental validation.