Viscous shear effect in non-Newtonian lubrication of finite porous elastic bearings

Abstract

Purpose The purpose of this study is to investigate the viscous shear effect on finite porous elastic journal bearings lubricated with non-Newtonian couple stress fluid. Design/methodology/approach Based on Stokes micro-continuum mechanics, the modified Reynolds equation including bearing deformation was derived. The porous flow was modeled by the complete Darcy–Brinkman equation. To show the viscous shear effects, bearing characteristics including load capacity and friction factor are compared to those obtained from Darcy model with Beavers–Joseph slip conditions (slip flow model [SFM]) by developing a computer program and discussed for different couple stress values, permeabilities and elastic deformation parameters. Findings It is found that the viscous shearing forces effects of the Brinkman model increase the load capacity and friction factor compared to those derived using SFM. Moreover, the couple stresses increase the load capacity while decreasing the friction factor for both models. Originality/value This study introduces for the first time the viscous effect on finite porous elastic journal bearings lubricated with couple stress fluid.