Title: Hydrothermal performance of Al₂O₃/water nanofluid in a vented cavity including hot cylinder covered by a porous layer utilising LTNE approach

Authors: Farrokh Mobadersani; Amirreza Jamshid Malekara

Addresses: Department of Mechanical Engineering, Urmia University of Technology, Urmia, Iran ' Department of Mechanical Engineering, Urmia University of Technology, Urmia, Iran

Abstract: This paper aims to examine the heat transfer rate and flow characteristics of Al₂O₃/water nanofluid in a vented cavity containing a hot square cylinder covered by a layer of porous media. The local thermal non-equilibrium (LTNE) model is employed to couple heat transfer in the solid matrix and nanofluid of the porous domain. The governing equations are numerically solved using the finite element method. Effects of thermal conductivity ratio, Darcy number, Reynolds number, porous layer thickness, dimensionless heat transfer coefficient, and cylinder size, are investigated. The outcomes reveal that at Re = 50, inserting the porous layer can enhance the average Nusselt number by 122% compared to the non-porous case. Furthermore, based on the calculated performance evaluation criterion, the use of a porous layer provides effective hydrothermal performance in low Reynolds numbers. The results indicated that implementing local thermal equilibrium in higher Reynolds and Darcy numbers leads to unreliable results.

Keywords: vented cavity; mixed convection; nanofluid; local thermal non-equilibrium; LTNE; performance evaluation criteria; PEC.

DOI: 10.1504/PCFD.2024.140895

Progress in Computational Fluid Dynamics, An International Journal, 2024 Vol.24 No.5, pp.289 - 304

Received: 19 Sep 2023
Accepted: 11 Jan 2024
Published online: 03 Sep 2024 *

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