Free convection of Fe3O4-water nanofluid under the influence of an external magnetic source

Influence of external magnetic source on free convection of ferrofluid is reported in this paper. Obtaining systems have been solved through Control volume based finite element method. Influences of Rayleigh, Hartmann numbers, size of inner cylinder and volume fraction of Fe3O4 on hydrothermal characteristics are presented. Results indicate that both temperature gradient and nanofluid velocity decease with augment of Hartmann number. Thermal boundary layer thickness reduces with augment of rin. Nusselt number decreases with rise of Lorentz forces while it enhances with rise of buoyancy forces.