Effects of inertia in the steady state pressurised flow of a non-Newtonian fluid between two curvilinear surfaces of revolution: Rabinowitsch fluid model

摘要

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 naturewhich can be modelled as cubic stress model (Rabinowitsch model). The cubic stress model forpseudoplastic fluids is adopted because Wada and Hayashi have shown that the theoretical resultswith this model are in good agreement with the experimental results. The present theoretical analysisis to investigate the pseudoplastic effect along with the effect of rotational inertia on the pressuredistribution, frictional torque and fluid flow rate of externally pressurised flow in narrow clearancebetween two curvilinear surfaces of revolution. The expression for pressure has been derived usingenergy integral approach. To analyse and discuss the effects of pseudoplasticity and fluid inertia onthe pressure distribution, fluid flow rate and frictional torque, the examples of externally pressurisedflow in the clearance between parallel disks and concentric spherical surfaces have been considered.