Non-Newtonian couple stress lubrication of MHD elastic journal bearings

Abstract

Purpose This paper aims to present a numerical model to examine the finite magneto-hydrodynamic (MHD) journal bearings performances including both non-Newtonian couple stress and bearing deformation impacts. Design/methodology/approach Based upon the MHD and Stokes theories, a novel expression of modified Reynolds equation including bearing deformation is obtained. The bearing elastic deformation impact is predicted by means of the Winkler model. Using the numerical differentiation approach, the film pressure is iteratively solved. Different bearing characteristics are then numerically calculated. The validity of the proposed model was verified by comparing with some particular cases from literature. Findings From the numerical presented results, it is demonstrated that the conducting couple stress lubricant with an applied radial magnetic field results in an induced electric current density and thus significantly improves the performances of elastic journal bearings. Particularly, the load-carrying capacity is increased, whereas a reduction in friction factor is observed. Originality/value This numerical model is original, which combines both non-Newtonian couple stress and bearing deformation impacts on finite MHD journal bearings performances. It provides useful information in designing MHD journal bearings, given the lack of experimental studies.