ECCENTRIC OPERATION AND BLADE-LOSS SIMULATION OF A RIGID ROTOR SUPPORTED BY AN IMPROVED SQUEEZE FILM DAMPER

This paper outlines an improved squeeze film damper which reduces sign ificantly the dependence of the stiffness of conventional squeeze film dampers on the vibration amplitudes. This improved damper consists of a conventional squeeze film damper with a flexibility supported outer ring. This secondary flexible support is considered to be massless, a nd to have a constant stiffness and damping. Assuming the short bearin g approximation and the 'pi' film cavitation model, the performances o f this damper in preventing bistable operation and sub-synchronous and nonsynchronous motions are theoretically demonstrated for a rigid rot or supported on a squeeze film damper. Blade-loss simulations are carr ied out numerically.