Flow-Coupled Vibrations of Rotor and Seal

Abstract

We study the flow-coupled vibrations of an unbalanced rotor and a floating sealing ring. The rotor is high speed; its operating regimes are above second critical velocity. The ring is subjected to Coulomb friction force, which prevents its motion about the casing. At rotor rotation, the intensive vibrations of rotor and floating ring take place and the hydrodynamic forces in clearance between them are dominated. Non-impact and impact regimes are revealed and the latter are very dangerous for safety. In the stationary case, the analytical solutions for impact regimes are obtained; these show that synchronous oscillations of rotor and floating ring may occur. The non-stationary oscillations during startup and shutdown are also considered. Domains for the trouble-free non-impact regimes by various rotor velocities are determined. Rotor trajectories with impacts are submitted.