Core Variation of a Non-Newtonian Fluid in an Annular Cylinder

Abstract

The objective of the paper is to investigate the variation of core thickness of a non-Newtonian fluid in an annular cylinder at the entrance region. It is derived numerically, with no prior assumptions on the form of the Velocity profile. The thickness of the core is examined at each cross section of annuli for various values of Bingham number and aspect ratio by applying mass balance equation. The effect of various parameters on the flow rate are obtained graphically. The examination incorporates Bingham plastic fluids, Casson and Herschel-Bulkley fluid. The administering equations are solved using an iterative procedure by converting non-linear algebraic equation, expressing the variation in pressure in terms of core thickness obtained using the mass balance equation and plug core velocities along the boundary layers. The core thickness is obtained numerically by solving this equation using an iterative procedure. MATLAB programming tool has been employed to get the graphical variation of core thickness for different values of aspect ratio. The comparisons have been made between the obtained results and the results of Casson and Herschel-Bulkley fluids. Also, we find excellent agreement between our numerical results and the results available in literature.