Abstract
This paper presents a numerical study for the unsteady flow of a magnetohydrodynamic (MHD) Sisko fluid in annular pipe. The fluid is assumed to be electrically conducting in the presence of a uniform magnetic field. Based on the constitutive relationship of a Sisko fluid, the non-linear equation governing the flow is first modelled and then numerically solved. The effects of the various parameters especially the power index n, the material parameter of the non-Newtonian fluid b and the magnetic parameter B on the flow characteristics are explored numerically and presented through several graphs. Moreover, the shear-thinning and shear-thickening characteristics of the non-Newtonian Sisko fluid are investigated and a comparison is also made with the Newtonian fluid. Copyright (C) 2009 John Wiley & Sons, Ltd.