Experimental investigation on heat transfer characteristics in rectangular duct flow of a magnetic fluid under magnetic field

Forced convective heat transfer characteristics in a rectangular duct flow of a magnetic fluid under a magnetic field were investigated experimentally. Experiments were performed in which the magnetic field intensity was changed from 0 mT to 500 mT. The Reynolds number based on the hydraulic diameter was set to 820 (laminar flow), 1630 and 2450 (turbulent flow). The magnetic fluid in the rectangular duct was heated with a uniform heat flux. The results of the experiments showed that in the case of laminar flow of the magnetic fluid, when the magnetic field is applied to the magnetic fluid flow, the heat transfer coefficient increases locally in the region where the magnetic field exists. In contrast, in the turbulent flow of the magnetic fluid, heat transfer is not enhanced, but slightly decreases.