Dynamic Analysis of a Turbocharger Rotor-Bearing System in Transient Operating Regimes

This paper presents a hydrodynamic analysis of the rotor-bearing system of a high-speed turbocharger (TC) rotor supported on the floating ring bearings in transient operating conditions. By considering the temperature-dependent oil-film viscosity of lubricant and film clearances, the pressure distributions and dynamic bearing forces are calculated from the two-dimensional Reynolds equation. The dynamic behavior and stability-related issues are explained while the rotor is in start-up and shut-down conditions. The effects of various parameters including in-phase and out-of-phase unbalances at the disks on the dynamics of the overall system are studied. The generalized approach facilitates the user to select the optimum clearances and lubricant type as per the temperature rise in the system.