WoS İndeksli Yayınlar Koleksiyonu / WoS Indexed Publications Collection
Permanent URI for this collectionhttps://hdl.handle.net/11147/7150
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Conference Object The Effect of Permanent Magnet Location on The Performance of Ferrofluid Based Spncml(Begell House, inc, 2022) Bozkir, Selim Can; Karadeniz, Ziya Haktan; Cobanoglu, Nur; Doganay, Serkan; Karadeniz, Ziya Haktan; Turgut, Alpaslan; 03.06. Department of Energy Systems Engineering; 03. Faculty of Engineering; 01. Izmir Institute of TechnologyFerrofluids are suspensions of ferromagnetic nanoparticles (iron, cobalt, nickel, magnetite, hematite, etc.) dispersed in non-magnetic base fluids. They have application potential in many fields due to the tunable thermophysical properties and the manipulation capability of the ferromagnetic nanoparticles under the influence of an external magnetic field. This numerical study investigates the effect of external magnetic field location on the performance of ferrofluid-based single phase natural circulation mini loop (SPNCmL) in which the driving mechanism is resulting buoyancy forces of density gradient caused by temperature difference. Since the working fluid exhibits higher magnetization at low temperatures, effects of the magnetic field have been investigated for the low-temperature side of the SPNCmL by placing a permanent magnet at the cooling-end outlet and heating-end inlet. The steady 3D numerical model was developed in the COMSOL Multiphysics by coupling three different physics: magnetic field (no current), heat transfer in fluid, and laminar flow. The performance of the SPNCmL working with water-based Fe3O4 ferrofluid under an external magnetic field was evaluated in terms of the maximum temperature (T-max), the temperature difference between heater inlet and outlet (Delta T-heater), the effectiveness (epsilon), and the flow distribution. In addition, the magnetic field effect on the fluid flow was visualized by velocity and the temperature distributions at the critical cross-sections.Article Citation - WoS: 3Citation - Scopus: 3Investigation of External Magnetic Field Effect on the Performance of Ferrofluid-Based Single-Phase Natural Circulation Loops(Elsevier, 2023) Bozkır, Selim Can; Karadeniz, Ziya Haktan; Çobanoğlu, Nur; Doğanay, Serkan; Karadeniz, Ziya Haktan; Elçioğlu, Elif Begüm; Turgut, Alpaslan; 03.06. Department of Energy Systems Engineering; 03. Faculty of Engineering; 01. Izmir Institute of TechnologyThe goal of this study is to investigate the performance of a Single-Phase Natural Circulation mini Loop (SPNCmL) operating under the influence of an external magnetic field (EMF). For this purpose, a numerical SPNCmL model working with Fe3O4 ferrofluids (1-3 vol%.) under the influence of an EMF is developed to reflect the effect of a NdFeB permanent magnet with a remanence of 1.22 T located at the outlet of the cooler-end for the magnetic field generation. System characteristics such as temperature difference at heater-end (& UDelta;Theater) and maximum temperature (Tmax) and performance in terms of effectiveness (& epsilon;) are investigated. In addition, the effect of EMF on boundary layer energy transport along the cooler-end is evaluated in terms of the change in the local Nusselt number. Applying an EMF dramatically affects the system performance in terms of an increase in & UDelta;Theater and & epsilon;, respectively up to 34% and 25% compared to those with water. Tmax values are obtained by up to 9% higher for Fe3O4 ferrofluids compared to water, while applying EMF results in an increment in Tmax by up to 5%. Improved heat transfer performance by employing EMF at the cooler-end outlet of the SPNCmLs emphasizes their potential in cooling applications.