Finite element analysis of elliptical bearings lubricated by a non-newtonian fluid

Additive-fortified lubricants behave as non-newtonian fluids (shear thinning or shear thickening). The effect of this non-linear behaviour on the performance characteristics of finite-width elliptical hydrodynamic journal bearings was investigated using the cubic shear stress law. The finite element method with Galerkin's technique was used to solve in cylindrical coordinates the Navier-Stokes equations that represent the flow field in the clearance space of a bearing using newtonian fluids and the non-newtonian effect was then introduced by modifying the viscosity term for the model in each iteration. The results for non-newtonian lubricants are compared with those for newtonian lubricants.