Experimental Investigation on Heat Transfer and Pressure Drop Characteristics of Graphene Oxide/Water Nanofluid in a Circular Tube

ABSTRACT The forced convective heat transfer and pressure drop characteristics of Graphene oxide/water nanofluids flowing inside a horizontal circular tube were experimentally investigated. The heat transfer and the pressure drop within the flowing nanofluids were measured and compared with the corresponding data for base fluid (pure water). Graphene oxide (GO) nanoparticles were synthesized by the modified Hummers method. GO particles dispersed in pure water are used as the working fluid. Consideration is given to the effect of the inclusion of nanoparticles on heat transfer enhancement, thermal conductivity, viscosity, and pressure loss in the turbulent flow. Four volume fractions of 0.05%, 0.10%, 0.15% and 0.20% are tested for GO/water nanofluids. The Reynolds number is ranged from 3000 to 10000. It is found from the study that (i) heat transfer enhancement is caused by suspending nanoparticles and becomes more pronounced with an increase in the particle volume fraction, (ii) the nanofluids have substantially higher value of Nusselt number than the same liquids without nanoparticles and the Nusselt number of nanofluids increase in accordance with an increase of the Reynolds number, (iii) the nanofluids showed an increased heat transfer coefficient with respect to that of pure water on a constant Reynolds number, (iv) the viscosity and thermal conductivity of Graphene oxide nanofluid increase in accordance with an increase of the volume fraction, (v) the change in viscosity and friction factor due to the addition of the nanoparticles increased the pressure drop and pumping power. Keywords: Graphene oxide, Nanofluid, Volume Fraction, Heat Transfer, Pressure drop Volume & Issue No. = Volume 4, Issue 3, March 2016