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Experimental and Numerical Study on Ferrohydrodynamic and Magneto-Convection of Fe3O4/Water Ferrofluid in a Sudden Expansion Tube with Dimpled Fins     
Yazarlar
Emrehan Gürsoy
Doç. Dr. Mehmet GÜRDAL Doç. Dr. Mehmet GÜRDAL
Kastamonu Üniversitesi, Türkiye
Engin Gedik
Karabük Üniversitesi, Türkiye
Kamil Arslan
Karabük Üniversitesi, Türkiye
Özet
Background: This study experimentally and numerically addresses magnetohydrodynamic forced convection including dimpled fins, Fe3O4/water ferrofluid, and DC magnetic field. In this research, focusing on the thermo-hydraulic performance improvement of a sudden expansion tube. It has been used different inlet diameters, dimple sizes, ferro nanoparticle concentrations, and magnetic field strengths to examine the heat transfer and fluid dynamics characteristics of the system. Methods: The study consists of two parts, i) experimental and ii) numerical. Steady-state, incompressible, Newtonian flow were considered but chemical reaction, viscous dissipation, buoyancy, and radiative heat transfer were neglected in this study. On the other hand, numerical solutions were carried out for single-phase method. This study was first compared with the studies in the literature on the flow in a sudden expansion tube without dimpled fins and the error rate was found to be less than 10 %. In the analysis, dimpled fins with d=3, 5, and 7 mm at each P=15 mm (P/d=5.0, 3.0, and 2.14) have been used. As working fluid, Fe3O4/water ferrofluid with volume concentration of φ=1.0 % and 2.0 % have been analyzed. Additionally, DC magnetic fields, which strength of Ha=0.1, 0.3, 0.5, 1.1, 3.2, and 5.3 (B =0.01, 0.03, 0.05, 0.1, 0.3, and 0.5T), have been applied on the sudden expansion tube surface as external force. Significant findings: Dimpled fins enhance the heat transfer by disrupting the boundary layer and forming secondary flows, while the ferrofluid increases the thermal conductivity and viscosity of the base fluid. Based on these explanations, dimpled fins increased the convective heat transfer rate at the rate of 96.0 % compared with smooth tube. In addition, Fe3O4/water ferrofluid with φ=2.0 % performed the highest performance and performance evaluation criteria increased by 8.5 %. The magnetic field also contributes to the heat transfer enhancement by inducing Lorentz force and mixing the flow. Excessive increasing of magnetic field strength adversely affected the system performance, and the highest performance evaluation criterion is acquired at Ha=3.2 by increasing 3.9 %. Compared with smooth tube, compound effect of dimpled fins, Fe3O4/water ferrofluid, and magnetic field improved the average Nusselt number and performance evaluation criterion at the rate of 279.8 % and 207.9 %, respectively.
Anahtar Kelimeler
Dimpled fin | Ferrofluid | Heat convection | Magnetic field | Nanofluid | Sudden expansion tube
Makale Türü Özgün Makale
Makale Alt Türü SSCI, AHCI, SCI, SCI-Exp dergilerinde yayımlanan tam makale
Dergi Adı Journal of the Taiwan Institute of Chemical Engineers
Dergi ISSN 1876-1070
Dergi Tarandığı Indeksler SCI-Expanded
Dergi Grubu Q1
Makale Dili İngilizce
Basım Tarihi 01-2024
Cilt No 164
Sayı 1
Doi Numarası 10.1016/j.jtice.2024.105676
Makale Linki https://www.sciencedirect.com/journal/journal-of-the-taiwan-institute-of-chemical-engineers