Static and dynamic behaviour of squeeze-film lubrication of narrow porous journal bearings with coupled stress fluid

Abstract

In this paper an attempt has been made to study the rheological effects of coupled stress fluids on the static and dynamic behaviour of squeeze-film lubrication in porous journal bearings. A generalized modified form of the Reynolds equation is derived for the squeeze-film lubrication of porous journal bearings with a coupled stress fluid as the lubricant. The analysis takes into account the velocity slip at the surface of the porous medium by using the Beavers-Joseph criterion. A closed-form expression for the squeeze-film pressure is obtained for the narrow porous journal bearing. The cases of a constant applied load and an alternating applied load are analysed. It is observed that the effect of coupled stress is to increase significantly the squeeze-film pressure and the load-carrying capacity compared with the Newtonian case. Under cyclic loading, the coupled stresses developed in the fluid cause a reduction in the velocity of the journal centre and an increase in the minimum permissible squeeze-film thickness.