Heat Transfer Augmentation in a Mini-channel Using Magnetic Nanofluid and Magnetic Vortex

This study examines the synergistic effects of non-uniform magnetic fields and vibrations on convective heat transfer in a rectangular 2D domain. A laminar flow of magnetic nanofluid (Fe3O4) was passed through a heated channel at varying Reynolds numbers from 150 to 1000 in the presence of varying magnetic fields with strengths ranging from 0G to 2000G applied at x/D = 0.375. Two intensities of vibrations were applied - low vibration (5 mm amplitude and 6 Hz frequency), and high vibration (5 mm amplitude and 25 Hz frequency). The interaction between vibrations and magnetic fields enhanced the Nusselt number on the heated boundary but the pressure drops across the channel also increased. The Thermal Enhancement Factor (TEF) was therefore utilized for the comprehensive evaluation of heat transfer characteristics. It was observed that TEF was greater than one for all the cases of induced mechanical vibration in presence of magnetic fields reaching a maximum of 1.27 at 150 Re with high vibration and maximum intensity of magnetic field. These findings demonstrate the potential for using non-uniform magnetic fields and vibrations to enhance fluid system convective heat transfer.