부제 : ABSTRACT INTRODUCTION ROTOR-BEARING DYNAMIC MODEL FLUID FILM MODEL THERMAL SHAFT AND BEARING MODEL SIMULATION MODEL SIMULATION RESULTS AND DISCUSSIONS CONCLUSIONS REFERENCES
This paper is focused on a Morton instability problem considering spinning journal asymmetric heating and the resultant thermal bow induced vibration oscillation with a long period. Nonlinear time transient rotor-bearing dynamic simulation is adopted for a time varying vibration amplitude and temperature distribution. To solve the fluid force and lubricant temperature, varying viscosity Reynolds equation and energy equation are solved simultaneously considering the relationship between viscosity and temperature. Orbit time averaged heat flux boundary condition between lubricant and spinning journal is used for the asymmetric shaft heating. Dynamic behavior of a rotor-bearing system is significantly influenced by the thermal bow effect. Three-dimensional (3D) thermos-hydro-dynamic (THD) tilting pad journal bearing (TPJB) model is simulated and the corresponding results are presented. The effect of changes in TPJB pivot type is simulated and discussed.