Numerical simulation of non-Newtonian flows in journal bearings

We investigate the influence of rheological properties of inelastic and viscoelastic fluids in flows occurring in the annulus of eccentric cylinders, particularly in journal bearings. To compute these flows where vortex regions are encountered, the physical domain is split up into a finite number of sub-domains that are mapped into domains where open and closed streamlines are parallel and straight, by means of local mapping functions to be determined numerically. Such simplicity for the mapped streamlines makes it easy to handle time-dependent constitutive models in viscoelasticity. The results point out the role of shear-thinning properties and the influence of elasticity and underline the complex behavior of non-Newtonian fluids on the kinematics (velocities, vortex regions). The flow characteristics are notably highlighted by variations of the torque and the load on the inner cylinder versus the flow rate.