Experimental studies on heat transfer and friction factor characteristics of Al{sub 2}O{sub 3}/water nanofluid in a circular pipe under laminar flow with wire coil inserts

Journal Article · Mon Feb 15 00:00:00 EST 2010 · Experimental Thermal and Fluid Science

DOI:https://doi.org/10.1016/J.EXPTHERMFLUSCI.2009.10.001· OSTI ID:21262153

Chandrasekar, M; Suresh, S ^[1]; Chandra Bose, A ^[2]

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1. Department of Mechanical Engineering, National Institute of Technology, Tiruchirappalli 620015 (India)
2. Nanomaterials Laboratory, Department of Physics, National Institute of Technology, Tiruchirappalli 620015 (India)

In this paper, fully developed laminar flow convective heat transfer and friction factor characteristics of Al{sub 2}O{sub 3}/water nanofluid flowing through a uniformly heated horizontal tube with and without wire coil inserts is presented. For this purpose, Al{sub 2}O{sub 3} nanoparticles of 43 nm size were synthesized, characterized and dispersed in distilled water to form stable suspension containing 0.1% volume concentration of nanoparticles. The Nusselt number in the fully developed region were measured and found to increase by 12.24% at Re = 2275 for plain tube with nanofluid compared to distilled water. Two wire coil inserts made of stainless steel with pitch ratios 2 and 3 were used which increased the Nusselt numbers by 15.91% and 21.53% respectively at Re = 2275 with nanofluid compared to distilled water. The better heat transfer performance of nanofluid with wire coil insert is attributed to the effects of dispersion or back-mixing which flattens the temperature distribution and make the temperature gradient between the fluid and wall steeper. The measured pressure loss with the use of nanofluids is almost equal to that of the distilled water. The empirical correlations developed for Nusselt number and friction factor in terms of Reynolds/Peclet number, pitch ratio and volume concentration fits with the experimental data within {+-}15%. (author)

• OSTI ID: 21262153
• Journal Information: Experimental Thermal and Fluid Science, Vol. 34, Issue 2; Other Information: Elsevier Ltd. All rights reserved; ISSN 0894-1777
• Country of Publication: United States
• Language: English

Related Subjects

42 ENGINEERING
77 NANOSCIENCE AND NANOTECHNOLOGY
ALUMINIUM OXIDES
REYNOLDS NUMBER
CONVECTION
WATER
FRICTION FACTOR
LAMINAR FLOW
NUSSELT NUMBER
WIRES
EXPERIMENTAL DATA
SUSPENSIONS
NANOSTRUCTURES
PARTICLES
TUBES
PRESSURE DROP
TEMPERATURE DISTRIBUTION
TEMPERATURE GRADIENTS
CORRELATIONS
MIXING
PERFORMANCE