Heat transfer behaviours of nanofluids in a uniformly heated tube

In the present work, we consider the problem of the forced convection flow of water-gammaAl(2)O(3) and ethylene glycol-gammaAl(2)O(3) nanofluids inside a uniformly heated tube that is submitted to a constant and uniform heat flux at the wall. In general, it is observed that the inclusion of nanoparticles has increased considerably the heat transfer at the tube wall for both the laminar and turbulent regimes. Such improvement of heat transfer becomes more pronounced with the increase of the particle concentration. On the other hand, the presence of particles has produced adverse effects on the wall friction that also increases with the particle volume concentration. Results have also shown that the ethylene glycol-gammaAl(2)O(3) mixture gives a far better heat transfer enhancement than the water-gammaAl(2)O(3) mixture. (C) 2004 Elsevier Ltd. All rights reserved.