Table of Contents
International Scholarly Research Notices
Volume 2014, Article ID 736424, 7 pages
Research Article

Heat Transfer of Nanofluid in a Double Pipe Heat Exchanger

1Department of Chemical Engineering, Shahrood Branch, Islamic Azad University, Shahrood 36199-43189, Iran
2Department of Chemistry, Sciences Faculty, Arak Branch, Islamic Azad University, Arak, Iran
3Department of Chemical Engineering, Damghan Branch, Islamic Azad University, Damghan 36716-39998, Iran
4Department of Chemistry, Saveh Branch, Islamic Azad University, Saveh 39197-15179, Iran

Received 7 February 2014; Revised 10 June 2014; Accepted 6 July 2014; Published 10 November 2014

Academic Editor: Denis L. Nika

Copyright © 2014 Reza Aghayari et al. 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.


This paper investigates the enhancement of heat transfer coefficient and Nusselt number of a nanofluid containing nanoparticles (γ-AL2O3) with a particle size of 20 nm and volume fraction of 0.1%–0.3% (V/V). Effects of temperature and concentration of nanoparticles on Nusselt number changes and heat transfer coefficient in a double pipe heat exchanger with counter turbulent flow are investigated. Comparison of experimental results with valid theoretical data based on semiempirical equations shows an acceptable agreement. Experimental results show a considerable increase in heat transfer coefficient and Nusselt number up to 19%–24%, respectively. Also, it has been observed that the heat transfer coefficient increases with the operating temperature and concentration of nanoparticles.