Thermo-hydrodynamic Lubrication of Misaligned Porous Journal Bearings

Abstract

In this work, a numerical simulation for the thermo-hydrodynamic self-lubrication of misaligned porous circular journal bearing has been investigated. Mathematical model consists of a modified Reynolds equation to determine the pressure field of thin viscous oil film taking into account the oil leakage into the porous matrix, Darcy’s law to determine the fluid flow in the porous media and the energy and the heat conduction equations to determine the temperature field in oil film thickness and the bearing shaft . The equation used to evaluate the oil film thickness was modified to include the effect of the bearing misalignment. The governing equations with appropriate boundary conditions were simultaneously solved using finite difference approach. Direct iterative procedure with successive under relaxation has been adopted through the present work. The effects of the dimensionless permeability and misalignment parameters on the performance characteristics of porous journal bearing have been presented and discussed. The results obtained from this analysis indicate that bearing performance is greatly affected by such parameters. The mathematical model as well as the computer program prepared to solve the governing equations of the present work have been verified by comparing the results of the load carrying capacity and attitude angle obtained through this work with that obtained by Boubendir et al.. Good agreement between the results has been obtained with maximum deviations of 4.8% and 4% respectively.