**6. Conclusion**

In this study, graphene oxide-hydrogenated oil nanofluids were homogenized through combination of hydrodynamic cavitation and ultrasonication combination process at 25 ppm, 50 ppm and 100 ppm respectively. FTIR analysis had shown presence of large –OH groups concentration while TEM analysis shows severe defects and bends attributed to attachments of various groups on the surface. Findings have shown addition of graphene oxide into hydrogenated oil showed remarkable improvements of 12.00% in thermal conductivity enhancement at 100 ppm and 50°C. Furthermore, the rheological properties of hydrogenated oil nanofluid showed no significant changes in rheological behaviour when compared against the base fluid. Hydrogenated oil-based nanofluids have shown to possess both shear thinning and shear thickening behaviours at lower shear rates approaching higher shear rate range with increased viscosity at higher nanoparticle concentrations. Conventional thermal conductivity models were able to predict graphene oxide-based nanofluids accurately at higher particle concentration while Bingham Plastic model had shown to fit well against experimental data at all concentrations and temperature, thus proving addition of graphene oxide does not change the intrinsic behaviour of hydrogenated oil.
