A coupled numerical–experimental investigation of turbulent thermohydraulic performance of GO nanofluids

Abstract Enhancing the thermal efficiency of heat exchangers is a critical objective in modern thermal management systems, aimed at achieving energy savings, material optimization, and improved performance. The turbulent heat transfer and flow properties of graphene oxide–water nanofluid in a horizontal tube under constant heat flux circumstances are investigated in this work using both theoretical and experimental methods. To address the limited understanding of graphene oxide nanofluids under turbulent regimes, both numerical simulations using the Finite Volume Method (FVM) and experimental validation were conducted for nanoparticle concentrations of 0.025–0.1 wt% and Reynolds numbers from 5000 to 18000. Results revealed that the Nusselt number increased with both nanoparticle concentration and Reynolds number, achieving a maximum enhancement of 36.36%, while the friction factor increased by 128.57% at a nanoparticle concentration of 0.1 wt%. Despite the moderate increase in pressure drop, the overall thermal performance improvement demonstrates the potential of graphene oxide–water nanofluids as efficient coolants for advanced heat exchangers and energy systems.