THERMAL SCIENCE

International Scientific Journal

Mahmoud Salari

,

Ali Mohammadtabar

,

Mohammad Mohammadtabar

EFFECTS OF CIRCULAR CORNERS AND ASPECT-RATIO ON ENTROPY GENERATION DUE TO NATURAL CONVECTION OF NANOFLUID FLOWS IN RECTANGULAR CAVITIES

ABSTRACT
In this paper, entropy generation induced by natural convection of cu-water nanofluid in rectangular cavities with different circular corners and different aspect-ratios were numerically investigated. The governing equations were solved using a finite volume approach and the SIMPLE algorithm was used to couple the pressure and velocity fields. The results showed that the total entropy generation increased with the increase of Rayleigh number, irreversibility coefficient, aspect ratio or solid volume fraction while it decreased with the increase of the corner radius. It should be noted that the best way for minimizing entropy generation is decreasing Rayleigh number. This is the first priority for minimizing entropy generation. The other parameters such as radius, volume fraction, etc are placed on the second priority. However, Bejan number had an inverse trend compared with total entropy generation. As an exception, Bejan number and total entropy number had the same trend whenever solid volume fraction increased. Moreover, Nusselt number increased as Rayleigh number, solid volume fraction or aspect ratio increased whereas it decreases with the increase of corner radius.
KEYWORDS
entropy generation, nanofluid, circular corners, rectangular cavity, natural convection, numerical analysis
PAPER SUBMITTED: 2013-02-01
PAPER REVISED: 2015-03-07
PAPER ACCEPTED: 2015-03-20
PUBLISHED ONLINE: 2015-04-04
DOI REFERENCE: https://doi.org/10.2298/TSCI130201034S
CITATION EXPORT: view in browser or download as text file
THERMAL SCIENCE YEAR 2015, VOLUME 19, ISSUE Issue 5, PAGES [1621 - 1632]
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Effects of circular corners and aspect-ratio on entropy generation due to natural convection of nanofluid flows in rectangular cavities

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