In many practical situations fluids are normally blended with additives (viscosity index improvers, viscosity thickeners, viscosity thinners) due to which they show pseudoplastic and dilatant nature which can be modelled as cubic stress model (Rabinowitsch model). The cubic stress model for pseudoplastic fluids is adopted because Wada and Hayashi have shown that the theoretical results with this model are in good agreement with the experimental results. The present theoretical analysis is to investigate the pseudoplastic effect along with the effect of rotational inertia on the pressure distribution, frictional torque and fluid flow rate of externally pressurised flow in narrow clearance between two curvilinear surfaces of revolution. The expression for pressure has been derived using energy integral approach. To analyse and discuss the effects of pseudoplasticity and fluid inertia on the pressure distribution, fluid flow rate and frictional torque, the examples of externally pressurised flow in the clearance between parallel disks and concentric spherical surfaces have been considered.

In the present theoretical analysis, the combined effects of slider curvature and non-Newtonian pseudoplastic and dilatant lubricants (lubricant blended with viscosity index improver) on the steady and dynamic characteristics of pivoted curved slider bearings have been investigated for Rabinowitsch fluid model. The modified Reynolds equations have been obtained for steady and damping states of bearing. To solve the modified Reynolds equations, perturbation theory has been adopted. The results for the steady state characteristics (steady state film pressure, load carrying capacity and centre of pressure) and dynamic characteristics (dynamic damping and dynamic stiffness) have been calculated numerically for various values of viscosity index improver using Mathematica. In comparison with the Newtonian lubricants, higher values of film pressure, load carrying capacity, dynamic damping and dynamic stiffness have been obtained for dilatant lubricants, while the case was reversed for pseudoplastic lubricants. Significant variations in the bearing characteristics have been observed for even small values of pseudoplastic parameter, that is, with the non-Newtonian dilatant and pseudoplastic behaviour of the fluid.