Nonlinear Dynamic Stability Analysis of Flexibly Supported Finite Oil Journal Bearings with Variable Viscosity Including Bearing Liner Surface Deformation

摘要

This paper analyses the stability characteristics of a rigid rotor mounted in flexibly supported hydrodynamic finite oil journal bearings considering pressure depended viscosity including the effect of elastic distortion on the surface of bearing liner. This theoretical analysis is intended to show how the effect of elastic distortion along with the flexible support on the journal bearing performance considering pressure depended viscosity, which can be calculated for threedimensional bearing geometries. The deformation equations for bearing surface will be solved simultaneously with hydrodynamic equations considering variable viscosity. A Nonlinear time transient method is used to simulate the journal and bearing centre trajectory and thereby to estimate the stability parameter. In this analysis forth order RungeKutta method is used to determine the locus of the journal and the bearing centre for the various operating conditions. The stability of the system is determined from the combined stability effect in journal and bearing centre. It has been found that stability decreases with increase of the elasticity parameter of the bearing and stability improves with increase of the viscosity parameter.