Micropolar Fluid Poro-Elastic Squeeze Film Lubrication between a Cylinder and a Rough Flat Plate — A Special Reference to Synovial Joint Lubrication

Abstract

In the present paper the effect of micropolar squeeze film lubrication between a cylinder and a poroelastic flat plate is presented. The synovial fluid is modeled as the micropolar fluid and the articular cartilage is considered to be a poroelastic in nature. The modified averaged Reynolds equation accounting for the randomized surface roughness structure as well as elastic nature of articular cartilage with micropolar fluid as lubricant is derived. The Christensen stochastic theory for rough surfaces is used to study the effect of two types of one dimensional surface roughness on the squeeze film characteristics of a cylinder and a rough poroelastic flat plate with micropolar fluid. Results are presented for the performance of the synovial joint with the experimentally validated values of the cartilage elasticity and permeability. It is observed that, the transverse roughness pattern improves the squeeze film characteristics whereas the squeeze film bearing performance is affected due to the presence of one-dimensional longitudinal surface roughness. These effects are more pronounced for the micropolar fluids.

Keywords

• synovial joint
• surface roughness
• poro-elastic
• articular cartilage
• micropolar fluid
• squeeze film