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Experimental investigation of convective
heat transfer of Al2O3/water nanofluid
in circular tube
Paper review
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Outline
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Introduction
Experimental set-up
Data analysis
Experimental results
Conclusion
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Introduction
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Choi at the Argonne National Laboratory was the first to employ
the particles of nanometer dimension suspended in solution as
nanofluid and showed considerable increase in the nanofluid
thermal conductivity.
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Lee et al. reported that the suspension of 4.0%volume 35 nm
CuO particles in ethylene glycol showed20% increase in thermal
conductivity.
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Choi et al. observed 160% enhancement in thermal conductivity
ofengine oil with 1.0% volume carbon nanotube.
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Xuan and Li investigated heat transfer of Cu/water nanofluid
under constant wall heat flux in turbulent flow regime and
concluded that convective heat transfer enhancement of nanofluid
may be related to thermal conductivity increase or random
movement and dispersion of nanoparticles in nanofluid.
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Wen and Ding have studied Al2O3/water nanofluid heat transfer
in laminar flow under constant wall heat flux and reported an
increase in nanofluid heat transfer coefficient with Reynolds
number and nanoparticles concentration particularly at the
entrance region.
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The aim of the present paper is to study laminar flow convective
heat transfer of Al2O3/water nanofluid under constant wall
temperature and different concentrations of nanoparticles.
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Experimental set-up
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Experimental results
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Conclusion
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The experimental results indicate that heat transfer coefficient of
nanofluids increases with Peclet number as well as nanoparticles
concentration.
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It is concluded that thermal conductivity increase is not the sole
reason for heat transfer enhancement in nanofluids.
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Other factors such as dispersion and chaotic movement of
nanoparticles, Brownian motion and particle migration may play
role in heat transfer augmentationdue to nanoparticles.
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Particle fluctuations and interactions,especially in high Peclet
number may cause the change in flow structure and lead to
augmented heat transfer due to the presence of nanoparticles.
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Thank You
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