Stability analysis of a rigid rotor supported on hydrodynamic journal bearings with rough surfaces using the stochastic finite element method

Abstract

The effect of surface roughness on the stability characteristics of hydrodynamic journal bearings has been studied. Roughness has been considered to be a stochastic variable, which is stationary, ergodic with mean zero. Both one-dimensional roughness (longitudinal and transverse) and two-dimensional roughness (isotropic) have been studied using the stochastic finite element method. Journal bearings with different width-diameter ratios have also been considered. It is seen that the transverse roughness tends to increase the stability (non-dimensional mass parameter) whereas in the case of isotropic roughness there is a decrease when compared with the smooth bearing. Longitudinal roughness has a marginal effect of decreasing the stability of hydrodynamic journal bearings with rough surfaces.