Theoretical investigation of the effects of viscosity variation, couple stress, and slip velocity on squeeze film lubrication of porous conical bearings

This study examines the effects of viscosity variation and velocity slip on the performance of porous conical bearings lubricated with a couple stress fluid. Darcy’s law is used to describe fluid flow through the porous medium, while Stokes’ couple stress theory accounts for the microstructure of the lubricant. A modified Reynolds equation is developed by incorporating viscosity variation and slip effects. Numerical results illus- trate the influence of couple stress, slip velocity, permeability, and viscosity variation on pressure distribution, load-carrying capacity, and squeeze film time. It is observed that an increase in the couple stress parameter enhances the pressure and load capacity, while higher permeability tends to reduce the supporting ability of the bearing. The presence of slip at the boundary modifies the flow behaviour and contributes to improved lubrica- tion characteristics. The combined effects of porous structure and slip lead to better aggregate performance, and the use of couple stress fluids significantly improves lubrication efficiency and operational reliability.

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