CFB Based Transient Analysis of Hydrodynamic Journal Bearing

The effect of aspect ratio on linear and non linear stability of hydrodynamic journal bearing with Newtonian lubricant is presented. The aspect ratios (L/D) 0.5, 1.0 and 1.5 and eccentricity ratio of 0.2, 0.4, 0.6 and 0.8 are considered for the analysis of purpose. The Reynolds equation governing the flow of lubricant in the clearance space of a hydrodynamic journal bearing system has been numerically solved using Galerkin's FEM. The positive pressure zone is established using Reynolds boundary condition through iteratively. The journal centre motion trajectories are 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 and x and z=0.005 . The results help in predicting bearing life for smooth operation.