Experimental study of convective heat transfer and pressure drop of TiO2/water nanofluid

In this paper, an experimental study of convective heat transfer and pressure drop of turbulent flow of TiO2-water nanofluid through a uniformly heated horizontal circular tube has been performed. The spherical TiO2 nanoparticles with a nominal diameter of 15 nm are functionalized by a new chemical treatment and then dispersed in distilled water to form stable suspensions containing 0.1, 0.5, 1.0, 1.5 and 2.0% volume concentrations of nanoparticles. Results indicate that heat transfer coefficients increase with increasing the nanofluid volume fraction and it is not changed with altering the Reynolds number. The enhancement of the Nusselt number is about 8% for nanofluid with 2.0% nanoparticle volume fraction at Re = 11,800.