Secant-shaped porous slider bearing lubricated with couplestress fluids

Abstract

Purpose - To study the combined effects of permeability and couplestresses on the performance characteristics of a secant-shaped porous slider bearing lubricated with Stokes couplestress fluid. Design/methodology/approach - The modified Reynolds type equation governing the fluid film pressure is derived on the basis of Stokes microcontinuum theory of couplestress fluids by using Beavers-Joshep slip boundary conditions at the fluid-porous interface. The modified Reynolds equation is solved analytically and closed form expressions are obtained for the fluid film pressure, load carrying capacity, frictional force and centre of pressure. Findings - The bearing characteristics are computed for various values of the couple stress parameter, slip parameter and the permeability parameters. It is found that, the effect of couple stress is to increase the load carrying capacity and to decrease the coefficient of friction as compared to the Newtonian case. However, the effect of permeability parameter is to decrease the load carrying capacity. It is also found that, the effect of couple stresses is to shift the center of pressure towards the outlet edge. Research limitations/implications - The end effects are neglected in the analysis and these can be included in the study by considering full three-dimensional problem. Practical implications - Reduction in the load carrying capacity due to the presence of porous facing can be compensated by the use of lubricants containing additives of proper size. As a result the bearing performance can be improved. Originality/value - This paper provides closed form expressions for the bearing characteristics and are analyzed with respect to non-dimensional parameters, viz. couplestress parameter, slip parameter and permeability parameter. This paper offers help to design engineers to design efficient bearing systems. © Emerald Group publishing Limited.