Experimental determination of turbulent forced convection heat transfer and friction factor with SiO2 nanofluid

The heat transfer coefficients and friction factor with SiO2/water nanofluid up to 4% particle volume concentration are determined for flow in a circular tube under constant heat flux boundary condition. Experiments are undertaken in the Reynolds number range of 5000-27,000 at a bulk temperature of 30 °C. The Nusselt number and friction factor at 3.0% nanofluid particle concentration is respectively greater than the values of water by 32.7% and 17.1%. The pressure drop increases with particle concentration up to 3.0% and decreases thereafter. The nanofluid friction factor decreases with increase in Reynolds number at any concentration. The particle concentration at which SiO2 nanofluid gives maximum heat transfer has been experimentally determined.