Analysis of Hydrodynamic Journal Bearings Having Non-Newtonian Lubricants (Prandtl Model) by a Finite Element Method

Abstract

Additives are used to improve the performance of commercial lubricants. These lubricants behave like non-Newtonian fluids (shear thinning or shear thickening). The effect of the nonlinear behaviour on the performance characteristics of finite width journal bearings is investigated using the Prandtl model. The finite element method, using Galerkin's technique, has been used to solve the Navier-Stokes equations in cylindrical coordinates, representing the flow-field in the clearance space of a bearing using Newtonian fluids, and the non-Newtonian effect is introduced by modifying the viscosity term for the model in each iteration. The results applicable to shear-thinning (pseudoplastic) and shear-thickening (dilatant) lubricants are compared with the established results for Newtonian lubricants.