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Natural convection in differentially heated enclosures subjected to variable temperature boundaries

Abdulmajeed Mohamad (Department of Mechanical and Manufacturing, University of Calgary, Calgary, Canada)
Mikhail A. Sheremet (Department of Theoretical Mechanics, Tomsk State University, Tomsk, Russian Federation)
Jan Taler (Department of Mechanical Engineering, Cracow University of Technology, Cracow, Poland)
Paweł Ocłoń (Department of Mechanical Engineering, Cracow University of Technology, Cracow, Poland)

International Journal of Numerical Methods for Heat & Fluid Flow

ISSN: 0961-5539

Article publication date: 13 June 2019

Issue publication date: 17 October 2019

169

Abstract

Purpose

Natural convection in differentially heated enclosures has been extensively investigated due to its importance in many industrial applications and has been used as a benchmark solution for testing numerical schemes. However, most of the published works considered uniform heating and cooling of the vertical boundaries. This paper aims to examine non-uniform heating and cooling of the mentioned boundaries. The mentioned case is very common in many electronic cooling devices, thermal storage systems, energy managements in buildings, material processing, etc.

Design/methodology/approach

Four cases are considered, the left-hand wall’s temperature linearly decreases along the wall, while the right-hand wall’s temperature is kept at a constant, cold temperature. In the second case, the left-hand wall’s temperature linearly increases along the wall, while the right-hand wall’s temperature is kept a constant, cold temperature. The third case, the left-hand wall’s temperature linearly decreases along the wall, while the right-hand wall’s temperature linearly increases along the wall. In the fourth case, the left-hand and the right-hand walls’ temperatures decrease along the wall, symmetry condition. Hence, four scenarios of natural convection in enclosures were covered.

Findings

It has been found that the average Nusselt number of the mentioned cases is less than the average Nusselt number of the uniformly heated and cooled enclosure, which reflects the physics of the problem. The work quantifies the deficiency in the rate of the heat transfer. Interestingly one of the mentioned cases showed two counter-rotating horizontal circulations. Such a flow structure can be considered for passively, highly controlled mechanism for species mixing processes application.

Originality/value

Previous works assumed that the vertical boundary is subjected to a constant temperature or to a sinusoidal varying temperature. The subject of the work is to examine the effect of non-uniformly heating and/or cooling vertical boundaries on the rate of heat transfer and flow structure for natural convection in a square enclosure. The temperature either linearly increases or decreases along the vertical coordinate at the boundary. Four scenarios are explored.

Keywords

Acknowledgements

Erratum: It has come to the attention of the publisher that the article Abdulmajeed Mohamad, Mikhail Sheremet, Jan Taler and Paweł Ocłoń “Natural convection in differentially heated enclosures subjected to variable temperature boundaries” published in International Journal of Numerical Methods for Heat and Fluid Flow, listed the name of Abdulmajeed Mohamad and affiliation of Mikhail Sheremet incorrectly. This has now been amended.

Citation

Mohamad, A., Sheremet, M.A., Taler, J. and Ocłoń, P. (2019), "Natural convection in differentially heated enclosures subjected to variable temperature boundaries", International Journal of Numerical Methods for Heat & Fluid Flow, Vol. 29 No. 11, pp. 4130-4141. https://doi.org/10.1108/HFF-02-2019-0137

Publisher

:

Emerald Publishing Limited

Copyright © 2019, Emerald Publishing Limited

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