AL(2)O(3)-WATER NANOFLUID FALLING-FILM FLOW AND HEAT TRANSFER CHARACTERISTICS ON A HORIZONTAL CIRCULAR TUBE

作者：Jani Saeid^*

来源：Journal of Enhanced Heat Transfer, 2013, 20(3): 213-223.

• single-phase convection
• additives for liquids
• theoretical analysis
• falling-film

A heat transfer analysis of Al2O3 water nanofluid falling film over a heated horizontal circular tube used in heat exchangers and desalination systems is carried out and the results are compared to those of the base fluids. Based on extended analysis results, different correlations in terms of the film Reynolds, Prandtl, and Archimedes numbers, and on the nanoparticle volume fraction, p, for the nanofluid film and thermal boundary layer thicknesses, as well as the local and average heat transfer coefficients, have been derived. Three different values for volume fractions of the nanoparticles are considered; namely, 0, 0.03, and 0.06. It is found that the overall heat transfer coefficient over the tube generally increases when the volume fraction of the Al2O3 nanoparticles is increased. Moreover, the results show that the effect of the nanoparticle volume fraction on the heat transfer enhancement is more significant in the fully developed region compared to that of the developing region. The results of the present correlations are also shown to be in reasonably good agreement with predictions from other investigators for falling-film flow.

• 出版日期2013