Effect of magnetic field on heat transfer in rectangular duct flow of a magnetic fluid

Abstract

Effect of magnetic field on heat transfer in rectangular duct flow of a magnetic fluid was investigated experimentally. Experiment was performed with changing magnetic field intensity and this magnetic field can be varied from 0 mT to 500 mT. The magnetic fluid used in this experiment is water-based magnetic fluid named W-40. Magnetic fluid in the rectangular duct is heated with uniform heat flux. Reynolds number based on the hydraulic diameter was chosen 780 in magnetic fluid flow. Therefore, the flow in this experiment was laminar flow. As a result of this experiment, heat transfer coefficient increases locally in the region where magnetic field exists. This heat transfer coefficient becomes large with increasing magnetic field intensity and this increase of heat transfer coefficient is saturated. About 20 % of maximum increasing rate of heat transfer was obtained in the laminar flow of the magnetic fluid with applying magnetic field. © 2010 Published by Elsevier Ltd.