Effect of magnetic field on the hydrodynamic and heat transfer of magnetite ferrofluid flow in a porous fin heat sink

The present study numerically investigates the effects of a uniform external magnetic field and porous fins on convective heat transfer and pressure drop of magnetite (Fe3O4/water) nanofluid in a heat sink. Effects of volume fraction, porosity, Reynolds number, and magnetic field strength on the performance of the heat sink are studied. Results indicate that heat transfer increases at high volume fractions, fin porosities and magnetic field intensities and decreases with the Reynolds number. A 13% enhancement of heat transfer is obtained for the heat sink with solid fins by using ferrofluid compared to the pure water flow. This value grows up to 35% by using porous fins and imposing magnetic field to the heat sink. Moreover, using porous fins is shown to decrease the pressure drop while the magnetic field effect is not considerable. Therefore, it is concluded that the proposed methods result in a remarkable heat transfer enhancement while decreasing the pressure drop.