Performance of Hydrodynamic Journal Bearing Operating under Transient Wear

Abstract

Abstract The paper deals with a theoretical study concerning the effect of transient wear on the performance of hydrodynamic journal bearing. The eccentricity ratios are considered 0.3, 0.6 and for varying wear depth from 0.1 to 0.5 for the analysis of purpose. The Reynolds equations governing the flow of lubricant in the clearance space of a hydrodynamic journal bearing system with varying wear depth has been numerically solved using Galerkin’s FEM. The regime is assumed to be isothermal. The positive pressure zone is established using Reynolds boundary condition through iteratively. The various performance parameters which include static, dynamic and stability terms of worn journal bearing are presented with respect to relative wear depth. The journal centre motion trajectories are also obtained by numerically integrated linear and non-linear equation of motion using fourth order Runga-Kutta method. For this a computer program in Mat lab was developed based on analysis to draw the linear and non linear motion trajectories and in order to validate the developed program, the numerically simulated results computed from the present study are compared with the already published results in literature. For analysis purpose the initial values of velocities and displacement are taken as X ˙ ¯   =   Z ˙ ¯   =   0.0 {\bar {\dot X}}\, = \,{\bar {\dot Z}}\, = \,0.0 and x ¯ {\bar x} and   z ¯   =   0.005 {\bar z}\, = \,0.005 . The results help in predicting bearing life for smooth operation.