Heat exchange enhancement of ferrofluid flow into rectangular channel in the presence of a magnetic field

Heat exchange and Fe3O4/water nanofluid flow behaviors into horizontal channel subjected to the effect of a magnetic field was studied numerically. The basic equations were solved using the finite volume method with the time-splitting algorithm. The results were represented by temperature field, streamlines, velocity field, averaged and normalized Nusselt numbers, for various nanoparticles volume fractions, Reynolds numbers and magnetic numbers. Results show that the isotherms, the streamlines and the heat exchange rate are strongly changed by applying a magnetic field. A recirculation region is created near the magnetic source where the thermal boundary layer is removed enhancing so the local heat exchange. The overall heat exchange is enhanced by suspending nanoparticles and/or by increasing magnetic field strength. In the absence of a magnetic field, suspending nanoparticles can enhance heat exchange rate up to 20%. Under the only action of magnetic field a maximum 60% heat exchange enhancement is obtained. It can reach up to 86% as the combined effects of both nanoparticles and magnetic field are considered. (c) 2020 Elsevier Inc. All rights reserved.

Automated summary

The study showed that the heat exchange and flow behaviors of Fe3O4/water nanofluid in a horizontal channel are significantly altered by the application of a magnetic field, creating a recirculation region near the magnetic source and enhancing local heat exchange. The overall heat exchange can be enhanced by suspending nanoparticles and increasing magnetic strength.