Experimental and Numerical Investigations on Heat Transfer and Friction Loss of Functionalized GNP Nanofluids

Abstract

Heat transfer and friction loss characteristics of functionalized graphene nanoplatelet-based water (GNP-water) nanofluids are analyzed numerically and experimentally. A horizontal copper test section of 4 mm in diameter was used to run the experiment in close conduit flow. In the numerical analysis for two-phase flow mixture model, the velocity of nanofluids and profile temperature were assumed and in total 50 simulation cases, 2 different heat fluxes, 4 concentrations at Re range of 3900– 11,700 were investigated. In the results, significant enhancement was obtained in the thermal conductivity which increased up to 32%. After validation of the results, the highest enhancement in heat transfer coefficient and friction factor was obtained up to 119% and 10.2% by loading 0.1wt% of GNP-water nanofluids. It was perceived that heat transfer coefficient increases with increasing concentration of GNP-water nanofluids and flow Reynolds number (Re). The numerical and experimental results showed the good agreement with a maximum error of less than 4%. The experimental and numerical results reveal that the GNP-water can function as working fluids in heat transfer applications and can provide good alternatives to conventional working fluids in the thermal fluid systems.

Keywords: heat transfer, nanofluids, copper, turbulent flow, graphene nanoplatelet, propylene glycol