▎ 摘　　要

In this study, a hybrid of Fe3O4/Graphene was synthesized for nanofluid applications. The synthesized nano hybrid was characterized by X-Ray diffraction (XRD), Transmission electron microscopy (TEM), Zeta potential and Dynamic light scattering (DLS). Stability of the nanofluid was investigated at a wide pH range. Furthermore, rheological properties of the nanofluid including density and viscosity were evaluated. Thermal conductivity of the nanofluid was assessed at 0.1, 0.2 and 1%.Wt loadings of nanohybrid; in comparison to the base fluid 14-32% improvement was observed at 20-40 degrees C. Density and viscosity measurements of the nanofluid calculations for the base fluid indicated that the experimental data are in good agreement with the theoretical models. The convective heat transfer enhancement of the nanofluid flowing through a straight horizontal tube was investigated experimentally for a Reynolds number range of 2000-5000. In comparison to the base fluid 14.5% enhancement in convective heat transfer coefficient of nanofluid was observed.