فهرست نشریات علمی دسترسی آزاد ایران

This study presents a numerical investigation into the influence of the magnet position and its distance from the channel inlet on heat transfer and flow behavior of ferrofluid (FF), including Fe3O4/water flowing through a horizontal channel under a constant wall heat flux. Three magnet positions were considered—at the inlet, middle, and outlet of the channel—to identify the best configuration for heat transfer enhancement. Permanent magnets with a remanent magnetic flux density of 0.4 T were modeled. The nanoparticle concentration was 5 Vol.%, and the Reynolds number was 100. The effects of magnet positions on the local magnetic flux density, Kelvin force, streamlines, velocity and temperature distributions, and Nusselt number (Nu) were investigated. The problem was solved by assuming incompressible, laminar, and steady-state flow. The Galerkin weighted residual finite element method was used to solve the governing equations simultaneously. Results revealed that when magnets were positioned at the inlet or outlet, the magnetic field effects were localized and produced minimal impact on the flow and temperature fields. Conversely, when the magnets were located in the middle of the channel, the most substantial magnetic field gradients and Kelvin forces were generated, which created recirculation zones and increased fluid mixing, resulting in a more uniform temperature distribution and a significant enhancement in the local Nu and an average Nu of 5.31. Finally, this study proposes placing the magnet in the middle of the channel as the most effective configuration for enhancing convection heat transfer.