Entropy generation between two rotating cylinders with magnetohydrodynamic flow using nanofluids

Journal article

Authors/Editors

SOMCHAI WONGWISES

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Publication Details

Author list: Mahian O., Mahmud S., Wongwises S.

Publisher: American Institute of Aeronautics and Astronautics

Publication year: 2013

Journal: Journal of Thermophysics and Heat Transfer (0887-8722)

Volume number: 27

Issue number: 1

Start page: 161

End page: 169

Number of pages: 9

ISSN: 0887-8722

eISSN: 1533-6808

URL: https://www.scopus.com/inward/record.uri?eid=2-s2.0-84873640884&doi=10.2514%2f1.T3908&partnerID=40&md5=f64862a5a370d730384915ca809eda62

Languages: English-Great Britain (EN-GB)

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Abstract

The flow between two cylinders where one or both of the cylinders rotate has many practical applications such as swirl nozzles, rotating electrical machines, rotating disks, standard commercial rhymesters, and chemical and mechanical mixing equipment. In this paper, the effect of using TiO 2-water nanofluid 2% on entropy generation between two corotating cylinders in the presence of magnetohydrodynamic flow is investigated. An analytical approach is applied to solve the simplified governing equations in the cylindrical coordinate system. To calculate the thermal conductivity and viscosity of the nanofluid, two correlations, which are based on the experimental data, are used. The velocity field is obtained as modified Bessel functions, and then, using the expansions of these Bessel functions with three terms, the temperature field and, subsequently, the entropy generation rate are estimated. The results are presented for various parameters, including the entropy generation number (NS), Bejan number (Be), Hartmann number (M), Brinkman number (Br), and a group parameter (ω/Br). From the results, it is concluded that, at low Brinkman numbers (depending on the value of (ω/Brf), the average entropy generation number (NS)ave decreases with the increase in nanoparticle volume fraction. Copyright © 2012 by the American Institute of Aeronautics and Astronautics, Inc. All rights reserved.

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