Experimental Study of Magnetic Field Effect on Ferrofluid Nusselt number in a Square Channel

Document Type : Research Article


1 Ph.D. Student, Energy Conversion Dep., Faculty of Mechanical Eng., Shahrood University of Technology, Shahrood, Iran

2 Faculty of Mechanical and Mechatronics Engineering, Shahrood University of Technology, Shahrood, Iran

3 Faculty of Engineering and Mechatronics, Shahroud University of Technology, Shahroud, Iran


The present study aimed to experimentally investigate the heat transfer in Fe3O4 / water ferrofluid in a channel with a square cross-section, 0.8 m × 0.01 m × 0.01 m in dimension under the influence of uniform heat flux in a laminar flow regime in the presence of a local external magnetic field. Local Nusselt number investigated with different volume fractions (0.5 and 1 vol.%) in the presence of magnetic field and under the influence of some heat fluxes (30, 86.7, 229.95, 433.65, 573.51 Watts). The heat flux is applied evenly to all surfaces of the duct. The effect of heat flux, local magnetic field, and volume fraction of Ferro-particles on Nusselt number are investigated simultaneously and separately. Under the external local magnetic field, the Nusselt number increased 1.33 times. Under the influence of an external local magnetic field compared to pure water, the Nusselt number increased 1.36 times. These maximum values occurred in 1 vol.% and the lowest applied heat flux of 30 Watts. These results show that usage of Fe3O4 particles and externally applied magnetic fields have a synergistic effect on increasing the Nusselt number.


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