Application of electromagnets for forced convective heat transfer enhancement of magnetic fluids

The current research aims to numerically investigate the effect of a three-dimensional magnetic field generated by four electromagnets on the convective heat transfer of Fe3O4/Water ferrofluid in a parallel plate channel. Simulations have been carried out for different ferrofluid flow rates and concentrations, magnetic field intensities, and the electromagnets locations. The obtained numerical results have been compared with the experimental data of our previous work and accuracy of the numerical method has been determined at different conditions. Results show that the external magnetic field induces a quasi-oscillatory fluid motion between the surfaces of the channel that disturbs the thermal boundary layer and increases the heat transfer rate. A maximum of 24% heat transfer enhancement has been obtained at the optimum conditions. It is also concluded that the magnetic field has both increasing and decreasing effect on the fluid local pressure according to the sign of the magnetic field gradient. However, the overall pressure drop does not vary too much with the magnetic field intensity. Moreover, the accuracy analysis implies that the numerical method is more reliable in low magnetic field strengths and low Reynolds numbers.