Effect of replacing nanofluid instead of water on heat transfer in a channel with extended surfaces under a magnetic field
International Journal of Numerical Methods for Heat & Fluid Flow
ISSN: 0961-5539
Article publication date: 3 May 2019
Issue publication date: 6 June 2019
Abstract
Purpose
The purpose of this study is to conduct a numerical analysis of flow and heat transfer of water–aluminum oxide nanofluid in a channel with extended surfaces in the presence of a constant magnetic field. The channel consists of two parallel plates and five obstacles of constant temperature on the lower wall of the channel. The upper wall and the inlet and outlet lengths of the lower wall are insulated. A uniform magnetic field of the magnitude B0 is located beneath the obstacles. The nanofluid enters the channel with a uniform velocity and temperature, and a fully developed flow leaves the channel.
Design/methodology/approach
The control volume-based finite difference and the SIMPLE algorithm were used for numerical solution. In addition to examining the effect of the Reynolds number, the effects of Hartman number, the volume fraction of nanoparticles, the height of obstacles, the length of obstacles and the distance between the obstacles were investigated.
Findings
According to the results, the heat transfer rate increases with an increasing Reynolds number. As the Hartmann number increases, the heat transfer rate increases. The heat transfer rate also increases with an increase in the volume fraction of nanoparticles. The mean Nusselt number is reduced by an increasing height of obstacles. An increase in the distance between the obstacles in the presence of a magnetic field does not have a significant impact on the heat transfer rate. However, the heat transfer rate increases in the absence of a magnetic field, as the distance between the obstacles increases.
Originality/value
This paper is original and unpublished and is not being considered for publication elsewhere.
Keywords
Acknowledgements
The fourth author acknowledges the support provided by the “Research Chair Grant” National Science and Technology Development Agency (NSTDA), and King Mongkut’s University of Technology Thonburi through the “KMUTT 55th Anniversary Commemorative Fund”.
Citation
Aghakhani, S., Ghasemi, B., Hajatzadeh Pordanjani, A., Wongwises, S. and Afrand, M. (2019), "Effect of replacing nanofluid instead of water on heat transfer in a channel with extended surfaces under a magnetic field", International Journal of Numerical Methods for Heat & Fluid Flow, Vol. 29 No. 4, pp. 1249-1271. https://doi.org/10.1108/HFF-06-2018-0277
Publisher
:Emerald Publishing Limited
Copyright © 2019, Emerald Publishing Limited