Magnetohydrodynamic effects on flow structures and heat transfer over two cylinders wrapped with a porous layer in side

Abstract

Purpose

The analysis of the flow field and heat transfer around a tube row or tube banks wrapped with porous layer have many related engineering applications. Examples include the reactor safety analysis, combustion, compact heat exchangers, solar power collectors, high-performance insulation for buildings and many another applications. The purpose of this paper is to perform a numerical study on flows passing through two circular cylinders in side-by-side arrangement wrapped with a porous layer under the influence of a magnetic field. The authors focus the attention to the effects of magnetic field, Darcy number and pitch ratio on the mechanism of convection heat transfer and flow structures.

Design/methodology/approach

The Darcy-Brinkman-Forchheimer model for simulating the flow in porous medium along with the Maxwell equations for providing the coupling between the flow field and the magnetic field have been used. Equations with the relevant boundary conditions are numerically solved using a finite volume approach. In this study, Stuart and Darcy numbers are varied within the range of 0 < N < 3 and 1e-6 < Da < 1e-2, respectively, and Reynolds and Prandtl numbers are equal to Re=100 and Pr=0.71, respectively.

Findings

The results show that the drag coefficient decreases for N < 0.6 and increases for N > 0.6. Also, the effect of magnetic field is negligible in the gap between two cylinders because the magnetic field for two cylinders counteracts each other in these regions.

Originality/value

To the authors knowledge, in the open literature, flow passing over two circular cylinders in side-by-side arrangement wrapped with a porous layer has been rarely investigated especially under the influence of a magnetic field.

Citation

Rashidi, S., Abolfazli Esfahani, J., Valipour, M.S., Bovand, M. and Pop, I. (2016), "Magnetohydrodynamic effects on flow structures and heat transfer over two cylinders wrapped with a porous layer in side", International Journal of Numerical Methods for Heat & Fluid Flow, Vol. 26 No. 5, pp. 1416-1432. https://doi.org/10.1108/HFF-03-2015-0112