Next Article in Journal
The Thermal Entropy Density of Spacetime
Previous Article in Journal
The Relation between Granger Causality and Directed Information Theory: A Review
Entropy 2013, 15(1), 144-155; doi:10.3390/e15010144
Article

Numerical Study of Entropy Generation in a Flowing Nanofluid Used in Micro- and Minichannels

1
,
1,* , 2
,
3
,
1
,
1
 and
1
1 Department of Mechanical Engineering, Faculty of Engineering, University of Malaya, 50603, Kuala Lumpur, Malaysia 2 Department of Mechanical and Aeronautical Engineering, Clarkson University, Potsdam, NY 13699, USA 3 Department of Engineering Design and Manufacture, Faculty of Engineering Building, University of Malaya, 50603 Kuala Lumpur, Malaysia
* Author to whom correspondence should be addressed.
Received: 13 November 2012 / Revised: 4 December 2012 / Accepted: 7 December 2012 / Published: 7 January 2013
Download PDF [614 KB, 24 February 2015; original version 24 February 2015]

Abstract

This article mainly concerns theoretical research on entropy generation influences due to heat transfer and flow in nanofluid suspensions. A conventional nanofluid of alumina-water (Al2O3-H2O) was considered as the fluid model. Due to the sensitivity of entropy to duct diameter, mini- and microchannels with diameters of 3 mm and 0.05 mm were considered, and a laminar flow regime was assumed. The conductivity and viscosity of two different nanofluid models were examined with the help of theoretical and experimentally determined parameter values. It was shown that order of the magnitude analysis can be used for estimating entropy generation characteristics of nanofluids in mini- and microchannels. It was found that using highly viscous alumina-water nanofluid under laminar flow regime in microchannels was not desirable. Thus, there is a need for the development of low viscosity alumina-water (Al2O3-H2O) nanofluids for use in microchannels under laminar flow condition. On the other hand, Al2O3-H2O nanofluid was a superior coolant under laminar flow regime in minichannels. The presented results also indicate that flow friction and thermal irreversibility are, respectively, more significant at lower and higher tube diameters.
Keywords: nanofluid; entropy generation; microchannel; laminar flow; minichannel nanofluid; entropy generation; microchannel; laminar flow; minichannel
This is an open access article distributed under the Creative Commons Attribution License which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.

Share & Cite This Article

Further Mendeley | CiteULike
Export to BibTeX |
EndNote
MDPI and ACS Style

Hassan, M.; Sadri, R.; Ahmadi, G.; Dahari, M.B.; Kazi, S.N.; Safaei, M.R.; Sadeghinezhad, E. Numerical Study of Entropy Generation in a Flowing Nanofluid Used in Micro- and Minichannels. Entropy 2013, 15, 144-155.

View more citation formats

Related Articles

Article Metrics

For more information on the journal, click here

Comments

Cited By

[Return to top]
Entropy EISSN 1099-4300 Published by MDPI AG, Basel, Switzerland RSS E-Mail Table of Contents Alert