Effect of Magnetic Field on the Forced Convective Heat Transfer of Water–Ethylene Glycol-Based Fe 3 O 4 and Fe 3 O 4 –MWCNT Nanofluids.

This paper discusses the forced convective heat transfer characteristics of water–ethylene glycol (EG)-based Fe₃O₄ nanofluid and Fe₃O₄–MWCNT hybrid nanofluid under the effect of a magnetic field. The results indicated that the convective heat transfer coefficient of magnetic nanofluids increased with an increase in the strength of the magnetic field. When the magnetic field strength was varied from 0 to 750 G, the maximum convective heat transfer coefficients were observed for the 0.2 wt% Fe₃O₄ and 0.1 wt% Fe₃O₄–MWNCT nanofluids, and the improvements were approximately 2.78% and 3.23%, respectively. The average pressure drops for 0.2 wt% Fe₃O₄ and 0.2 wt% Fe₃O₄–MWNCT nanofluids increased by about 4.73% and 5.23%, respectively. Owing to the extensive aggregation of nanoparticles by the external magnetic field, the heat transfer coefficient of the 0.1 wt% Fe₃O₄–MWNCT hybrid nanofluid was 5% higher than that of the 0.2 wt% Fe₃O₄ nanofluid. Therefore, the convective heat transfer can be enhanced by the dispersion stability of the nanoparticles and optimization of the magnetic field strength. [ABSTRACT FROM AUTHOR]