Experimental Investigation of the Forced Convective Heat Transfer of hybrid Cu / Fe3O4 Nanofluids

In this paper the forced convection of Cu and Fe3O4 and Cu/Fe3O4 hybrid nanofluid in the laminar regime under constant heat flux codition is investigated experimentally. Experiments are carried out in three volume fractions of 1, 2, 4 % and three Re number of 600, 1200 and 1800, and local Nusselt number is measured. The results show that for nanofluid in simple and hybrid mode, with increasing the volume fraction of nanoparticles and Re number, the heat transfer coefficient is increased. results revealed that the heat transfer rate is augmented for both cases of simple and hybrid nanofluids with a rise in the particle volume fractions or the Re number. In addition, the comparison of the experimental data of Cu, Fe3O4 and hybrid nanofluids indicated that the heat transfer enhancement is more remarkable in the case of hybrid nanofluid. In the case of Cu/Water nanofluid, the greatest increase in the heat transfer vs. pure Water is 7.8% and in the hybrid nanofluid 11.9%. Also, the volume fraction of hybrid nanofluids is very effective in increasing the coefficient of heat transfer, so that in a 2% volume state, an increase is observed over other simple nanofluid volumetric fraction.