Using a non-uniform magnetic field to enhance heat transfer before a sudden compression in a 2D milli-channel

Abstract

With the integration of electronic devices advancing, effectively dissipating heat generated has become a challenging task. One promising solution is utilizing heat convection as a powerful tool. However, a notable issue arises when encountering an obstacle, such as a resistor requiring cooling. In these cases, the flow slows down, weakening heat transfer. In order to model this obstacle, it can be perceived as a sudden compression. The critical area of interest lies where the horizontal wall approaches the vertical side of the obstacle. This study examines the use of non-uniform magnetic fields to explore various arrangements aimed at enhancing thermal energy transfer in this critical region. These arrangements include placing a single dipole beneath either the lower or upper walls and utilizing two or three single dipoles simultaneously beneath the heated wall. The ferrofluid used in this study is EMG-308. The findings of this study demonstrate that heat transfer improves when single or multiple dipoles are positioned downstream of the step wall on the heated wall. For instance, by having three dipoles of equal strength in that area, the minimum Nusselt number is enhanced by 300%, resulting in a Nusselt number before the step that surpasses the Nusselt number immediately after the step.