investigation of turbulent convective heat transfer and pressure drop of tio2/water nanofluid in circular tube

turbulent heat transfer behavior of titanium dioxide/water nanofluid in a circular pipe was investigated experimentally where the volume fraction of nanoparticles in the base fluid was less than 0.25%. the experimental measurements have been carried out in the fully-developed turbulent regime for various volumetric concentrations. the results indicated that addition of small amounts of nanoparticles to the base fluid augmented heat transfer remarkably. there was no much effect on heat transfer enhancement with increasing the volume fraction of nanoparticles. the measurements also showed that the pressure drop of nanofluid was slightly higher than that of the base fluid and increased with increasing the volume concentration. in this paper, experimental results have been compared with the existing correlations for nanofluid convective heat transfer coefficient in turbulent regime. finally, a new correlation of the nusselt number will be presented using the results of the experiments with titanium dioxide nanoparticles dispersed in water.