In this study, the steady state turbulent convective heat transfer and pressure drop characteristics of Al2O3-water nanofluid inside a circular tube were investigated experimentally. The effects of the volume fraction and Reynolds number were determined under constant heat flux. The results of the heat transfer and pressure drop characteristics with respect to appropriate variables were presented. It was observed that the heat transfer increased with the increase of Reynolds number. The heat transfer increased with an increase in the volume concentration With the exception of the particle volume concentrations of 2 and 4 vol.%. The highest heat transfer enhancement was achieved at Re = 8000 and Phi = 0.005. (c) 2013 Elsevier Inc. All rights reserved.