Title: Experimental studies on heat transfer and friction factor characteristics of Al₂O₃/water nanofluid under laminar flow with spiralled rod inserts

Authors: S. Suresh; M. Chandrasekar; P. Selvakumar; Tom Page

Addresses: Department of Mechanical Engineering, National Institute of Technology, Tiruchirappalli 620015, India. ' Department of Mechanical Engineering, National Institute of Technology, Tiruchirappalli 620015, India. ' Department of Mechanical Engineering, National Institute of Technology, Tiruchirappalli 620015, India. ' Department of Design and Technology, Loughborough Design School, Loughborough University, Leicestershire, LE11 3TU, UK

Abstract: An experimental investigation on the convective heat transfer and friction factor characteristics in the plain and spiralled rod inserts (pitch = 15 mm, 30 mm) in a plain tube under laminar flow with constant heat flux is carried out with Al₂O₃-water nanofluids. We study the effect of the inclusion of nanoparticles on heat transfer enhancement, thermal conductivity, viscosity, and pressure loss in the laminar flow region. For this, we synthesised Al₂O₃ nanoparticles by using microwave assisted chemical precipitation method and we measured size of nanoparticles by using XRD. The average size of particle is 40.3 nm, and then the nanoparticles dispersed in distilled water to form stable suspension containing 0.3%, 0.4%, 0.5% volume concentration of nanoparticles. The experimental results of Nusselt number for 0.5% nanofluid with spiralled rod inserts under laminar flow showed a maximum of 24% higher than the plain tube and the isothermal pressure drop of nanofluids with spiralled rod inserts were about 5% to 15% higher than the plain tube.

Keywords: nanoparticle synthesis; nanofluids; spiralled rods; heat transfer enhancement; Nusselt number; pressure drop; laminar flow; Al2O3-water; pitch ratio; volume concentration; nanoparticles; nanotechnology; aluminium oxide; friction; rod inserts; thermal conductivity; viscosity; pressure loss.

DOI: 10.1504/IJNP.2012.044496

International Journal of Nanoparticles, 2012 Vol.5 No.1, pp.37 - 55

Received: 20 Oct 2010
Accepted: 22 Mar 2011
Published online: 20 Aug 2014 *

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