Influence of Lubricant Film Cavitation on the Vibration Behavior of a Semifloating Ring Supported Turbocharger Rotor With Thrust Bearing

Abstract This contribution investigates the influence of outgassing processes on vibration behavior a hydrodynamic bearing supported turbocharger rotor. The examined rotor is radially by floating rings with outer squeeze-film damping and axially thrust bearings. Due to highly nonlinear properties, can be excited via lubricating film, which results in subsynchronous vibrations known as oil-whirl oil-whip phenomena. A significant occurrence phenomena attributed stiffness damping, depend kinematic state supporting elements, thermal condition, processes. For modeling behavior, Reynolds equation mass-conserving cavitation regarding two-phase model three-dimensional (3D) energy well heat conduction solved. To evaluate impact cavitation, run-up simulations are carried out assuming fully (half-Sommerfeld) or partially filled lubrication gap. resulting responses compared shaft motion measurement. Also, normalized eccentricity, minimum lubricant fraction, condition discussed.