Unsteady and porous media flow of reactive non-Newtonian fluids subjected to buoyancy and suction/injection

Abstract

Purpose

The purpose of this paper is to examine the unsteady pressure-driven flow of a reactive third-grade non-Newtonian fluid in a channel filled with a porous medium. The flow is subjected to buoyancy, suction/injection asymmetrical and convective boundary conditions.

Design/methodology/approach

The authors assume that exothermic chemical reactions take place within the flow system and that the asymmetric convective heat exchange with the ambient at the surfaces follow Newton’s law of cooling. The authors also assume unidirectional suction injection flow of uniform strength across the channel. The flow system is modeled via coupled non-linear partial differential equations derived from conservation laws of physics. The flow velocity and temperature are obtained by solving the governing equations numerically using semi-implicit finite difference methods.

Findings

The authors present the results graphically and draw qualitative and quantitative observations and conclusions with respect to various parameters embedded in the problem. In particular the authors make observations regarding the effects of bouyancy, convective boundary conditions, suction/injection, non-Newtonian character and reaction strength on the flow velocity, temperature, wall shear stress and wall heat transfer.

Originality/value

The combined fluid dynamical, porous media and heat transfer effects investigated in this paper have to the authors’ knowledge not been studied. Such fluid dynamical problems find important application in petroleum recovery.

Citation

Chinyoka, T. and Makinde, D.O. (2015), "Unsteady and porous media flow of reactive non-Newtonian fluids subjected to buoyancy and suction/injection", International Journal of Numerical Methods for Heat & Fluid Flow, Vol. 25 No. 7, pp. 1682-1704. https://doi.org/10.1108/HFF-10-2014-0329