Numerical study of the effect of non-uniform magnetic field on ferrofluid heat transfer in a channel containing a double-forwrad facing step

Articles in Press

Document Type : Original Article

Authors

• Hamid-Reza Bahrami ¹
• Mahziyar Ghaedi ²

¹ Assistant Professor, Department of Mechanical Engineering, Qom University of Technology, Qom, Iran

² MSc Student, Department of Mechanical Engineering, Qom University of Technology, Qom, Iran

10.22067/jacsm.2024.85877.1228

Abstract

Nowadays, liquid cooling channels are used for cooling of electronic equipment. These channels have to change the cross-section to pass over elements, so they undergo sudden contractions or expansions. These changes create areas that are unfavorable for heat transfer. Various methods have been proposed to improve heat transfer in these areas. In the present study, the possibility of using a non-uniform magnetic field to improve heat transfer in a millichannel including two sudden contractions has been discussed. In this study, it is assumed that a ferrofluid (EMG-805-a commercial brand) flows in the channel with a laminar regime, fully developed and steady state conditions. The walls of the channel are adiabatic, while the walls of the steps, which are in the vicinity of the electronic element, have a constant heat flux. The effects of different parameters, including locations of dipoles on the bottom and top walls, the number of dipoles, the Reynolds number, and the strength of the magnetic field on the improvement of heat transfer have been investigated. The obtained results show that the increase in Reynolds number and the strength of the magnetic field causes an increase in local Nusselt. The results show that applying a magnetic dipole on the bottom wall and just after the steps results in a significant increase in the local Nusselt number and an increase of 164.05% in the average Nusselt number compared to the case without a magnetic field.

Keywords

• Magnetic Field
• Ferrofluid
• Nusselt Number
• Heat Transfer
• Dipole
• Forward Facing Step

Main Subjects

• Heat transfer

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