On the squeeze film lubrication of long porous journal bearings with couple stress fluids

Purpose - This paper aims to advance the squeeze film characteristics of long partial journal bearings with couple stress fluid studied by Lin to include the effect of permeability on the squeeze film lubrication of long partial porous journal bearings with couple stress fluids. Design/methodology/approach - A semi-analytical and semi-numerical solution for the squeeze film lubrication of long porous partial journal bearings lubricated with couple stress fluid is presented in the paper. The modified Reynolds equation governing the fluid film pressure is derived. The modified Reynolds equation is solved analytically and closed form expressions for the squeeze film pressure and load carrying capacity are presented. The first-order non-linear equation for the time-height relation is solved numerically with the given initial condition. The effect of couple stresses and permeability on the squeeze film characteristics are discussed. Findings - It is found that the effect of couple stresses is to increase the load carrying capacity and to lengthen the squeeze film time as compared to the corresponding Newtonian case. The effect of permeability is to reduce the load carrying capacity and to decrease the squeeze film time as compared to the corresponding solid case. Originaiity/value - In the design of porous partial journal bearings, the reduction in the load carrying capacity and the response time can be compensated by the use of lubricants with proper microstructures by which the bearing life can be increased.