Analysis of asymptotic solutions for non-Newtonian fluid flow between two parallel discs with dissimilar in-plane motion

Abstract

The investigation on the flow of non-Newtonian (Casson) fluid is made between parallel discs, executing in-plane motion in different manners. The fluid motion is induced due to upper radially stretching or shrinking disc at the rate a and lower rotating disc at an angular velocity Ω, with plate separation h. The nondimensional Navier–Stokes (NS) equations are reduced to coupled ordinary differential equations (ODEs) by using a suitable similarity reduction. The effects of the Casson parameter, Reynolds number and rotation parameter are discussed. The numerical solutions of radial pressure gradient and shear stresses are found and compared with low R series solutions and large R asymptotic manners. Velocity profiles indicate the regions of zero azimuthal and radial shear stresses which are also discussed in detail. This paper represents the first study of non-Newtonian (NN) fluid flow in this geometry i.e. flow between parallel discs in which both execute in-plane motion in different manners.