5. Squeeze Film Bearing Characteristics for Synovial Joint Applications

Squeeze film lubrication in surfaces approaching each other with a normal velocity plays an important role in synovial joints. The objective of this study is to analyze the squeeze film load capacity characteristics of layered parallel plate and partial journal bearing lubricated by couple stress fluids employing one-dimensional analysis. The non-dimensional squeeze film pressure is derived solving one-dimensional modified Reynolds equation using squeeze film boundary conditions. The couple stress fluids are examined on the basis of Stokes micro-continuum theory which takes into account of lubricant properties with additives. Fluid flow in the porous region is analyzed using the Brinkman model. Parallel plate and partial journal bearing lubricated with couple stress fluids are evaluated for porous surface double adsorbent layer, porous–surface adsorbent layer, and surface–surface adsorbent layer. The non-dimensional squeeze film load capacity increases with (i) decline in porous layer permeability, (ii) surface to core layer dynamic viscosity ratio enhancement, and (iii) increase in couple stress effects. The porous–surface adsorbent layers with couple stress fluid film core layer improve the squeeze film bearing characteristics for synovial joint applications.