Turbulent forced convection heat transfer and thermophysical properties of Mgo-water nanofluid with consideration of different nanoparticles diameter, an empirical study

In the present paper results of an experimental study on thermal conductivity, dynamic viscosity and Nusselt number of turbulent forced convection of Magnesium Oxide-water nanofluid in a circular straight pipe is presented. The considered pertinent parameters are Reynolds number, nanoparticles volume fraction and nanoparticles diameter. The pure water and nanofluid with the nanoparticle volume fraction of 0.005, 0.01, 0.015, 0.02 and the nanoparticles diameter of 60, 50, 40 and 20 nm are considered. The experimental values of the thermal conductivity and the dynamic viscosity shows that traditional formulas underestimates these thermophysical parameters. Also the experimental results indicates that the existence of the nanoparticles in the pure water with all considered values of the nanoparticles volume fraction and diameter motivates the rate of heat transfer to increase. The nanofluids with higher volume fraction and smaller nanoparticles diameter results in higher Nusselt number.