Title: Effects of sinusoidal hot wavy walls on natural convection heat transfer and entropy generation inside a Γ-shaped enclosure

Authors: Ehsan Mahravan; Abbas Abbassi; Ehsan P. Afsharian

Addresses: Department of Mechanical Engineering, Amirkabir University of Technology, Hafez Ave., P.O. Box 15916, Tehran, Iran ' Department of Mechanical Engineering, Amirkabir University of Technology, Hafez Ave., P.O. Box 15916, Tehran, Iran ' Department of Mechanical Engineering, Amirkabir University of Technology, Hafez Ave., P.O. Box 15916, Tehran, Iran

Abstract: This paper deals with natural convection heat transfer and entropy generation inside a Γ-shaped enclosure with sinusoidal wavy edges on step like hot walls. The OpenFoam (http://www.openfoam.com) software is used and developed to solve this problem. Incompressible Newtonian fluid with constant properties and Boussinesq approximation is used. Equations are discretised using finite-volume method and SIMPLE algorithm is used to solve pressure-velocity coupled equations. Results are presented for various Rayleigh numbers, numbers of waves, wave amplitudes and wave shapes. Also, the effects of enclosure aspect ratio on heat transfer and entropy generation is studied. In all of the results, irreversibility factor is considered 10⁻³. It is seen that the presence of wavy edges interrupts fluid flow and reduces heat transfer while has negligible effect on entropy generation.

Keywords: natural convection; Gamma-shaped enclosure; sinusoidal wavy edges; OpenFOAM; SIMPLE; hot walls; heat transfer; entropy generation; finite volume method; fluid flow; irreversibility.

DOI: 10.1504/IJEX.2014.065106

International Journal of Exergy, 2014 Vol.15 No.1, pp.24 - 45

Received: 11 Apr 2013
Accepted: 29 Jul 2013
Published online: 30 Apr 2015 *

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