Experimental investigation on the ferrofluid flow in a horizontal mini channel under the constant magnetic field using PIV

Abstract

Applying the magnetic field alters the flow characteristics of the ferrofluids, chiefly accounting for heat transfer augmentation. To elucidate how changes in flow characteristics enhance heat transfer, the impact of a constant magnetic field on the laminar ferrofluid (Fe3O4/water nanofluid) flow inside a mini channel is visualized and quantitatively investigated through the PIV method. Experiments are accomplished at the magnetic flux density of 3200 G and the magnetic particle concentration of 0.0014 wt% for 0.30≤Re≤62.5. The effects of the magnetic field are scrutinized on the flow patterns and velocity profiles. The results indicate that at Re=0.30, the region of influence of the magnet is considerable, inducing a y-velocity component, which accelerates the fluid and improves heat transfer. At Re=31.5, two quasi-symmetrical recirculation zones are observed, enhancing the fluid mixing. Additionally, though diminishing the magnetic field effects, raising the Re number from 31.5 to 62.5 increases the overall vorticity magnitude by 45.5%.