Akademik Veri Yönetim Sistemi
19th Nanoscience and Nanotechnology Conference, Ankara, Türkiye, 27 - 29 Ağustos 2025, ss.259, (Özet Bildiri)
Experimental Investigation of Forced Convective Heat Transfer of Magnetic Nanofluid Under Different Magnetic Field Configurations and Volume FractionsEsra Yagci, Oguz Kaan Yagci * , Tulin Bali, Orhan AydinKaradeniz Technical University, Department of Mechanical Engineering, Trabzon, TurkiyeNanofluids can offer higher thermal conductivity compared to conventional heat transfer fluids. Ferrofluids, a subclass of nanofluids, are characterized by their magnetically responsive nanoparticles, which distinguish them from conventional nanofluids. When exposed to a magnetic field, metal oxide nanoparticles (Fe₃O₄, Fe₂O₃) in ferrofluids become polarized and behave like nanoscale magnets. This unique behavior enables significant improvements in heat transfer performance through magnetically induced changes in their thermal and physical properties. Due to these features, ferrofluids have shown great potential in a variety of thermal management applications [1–5].In this study, the forced convective heat transfer performance of water-based ferrofluids containing Fe₃O₄ nanoparticles at two different volume fractions (0.5% and 1%) was experimentally investigated in a circular stainless steel tube under the influence of a constant magnetic field. Permanent magnets generating a field strength of 700 G were placed along the flow path in two configurations (aligned and staggered) to evaluate the effect of magnetic field distribution. Experiments were carried out under constant heat flux conditions for Reynolds numbers ranging from 400 to 1000. In the study, the effect of different magnetic field distributions on heat transfer performance was investigated in detail, with particular attention to how this performance varies with nanoparticle concentration. For each case, local and average Nusselt numbers as well as pressure drops were measured. Furthermore, a Performance Evaluation Criterion (PEC) was employed to assess the overall efficiency of heat transfer enhancement relative to the pressure drop.The results demonstrate that the application of a magnetic field significantly enhances the convective heat transfer performance of the ferrofluid. This enhancement is more pronounced at lower Reynolds numbers, higher nanoparticle concentrations, and under staggered magnet arrangements with stronger magnetic field gradients. The maximum improvements in local and average Nusselt numbers were recorded at Re = 400 for the 1% volume fraction under staggered magnet placement, with increases of 94.59% and 36.57%, respectively.* This work is supported by Karadeniz Technical University- Scientific Research Projects Coordinatorship (BAP) (FHD-2023-10615).
Experimental Investigation of Forced Convective Heat Transfer of Magnetic Nanofluid Under Different Magnetic Field Configurations and Volume Fractions
Esra Yagci, Oguz Kaan Yagci * , Tulin Bali, Orhan AydinKaradeniz Technical University, Department of Mechanical Engineering, Trabzon, TurkiyeNanofluids can offer higher thermal conductivity compared to conventional heat transfer fluids. Ferrofluids, a subclass of nanofluids, are characterized by their magnetically responsive nanoparticles, which distinguish them from conventional nanofluids. When exposed to a magnetic field, metal oxide nanoparticles (Fe₃O₄, Fe₂O₃) in ferrofluids become polarized and behave like nanoscale magnets. This unique behavior enables significant improvements in heat transfer performance through magnetically induced changes in their thermal and physical properties. Due to these features, ferrofluids have shown great potential in a variety of thermal management applications [1–5].In this study, the forced convective heat transfer performance of water-based ferrofluids containing Fe₃O₄ nanoparticles at two different volume fractions (0.5% and 1%) was experimentally investigated in a circular stainless steel tube under the influence of a constant magnetic field. Permanent magnets generating a field strength of 700 G were placed along the flow path in two configurations (aligned and staggered) to evaluate the effect of magnetic field distribution. Experiments were carried out under constant heat flux conditions for Reynolds numbers ranging from 400 to 1000. In the study, the effect of different magnetic field distributions on heat transfer performance was investigated in detail, with particular attention to how this performance varies with nanoparticle concentration. For each case, local and average Nusselt numbers as well as pressure drops were measured. Furthermore, a Performance Evaluation Criterion (PEC) was employed to assess the overall efficiency of heat transfer enhancement relative to the pressure drop.The results demonstrate that the application of a magnetic field significantly enhances the convective heat transfer performance of the ferrofluid. This enhancement is more pronounced at lower Reynolds numbers, higher nanoparticle concentrations, and under staggered magnet arrangements with stronger magnetic field gradients. The maximum improvements in local and average Nusselt numbers were recorded at Re = 400 for the 1% volume fraction under staggered magnet placement, with increases of 94.59% and 36.57%, respectively.* This work is supported by Karadeniz Technical University- Scientific Research Projects Coordinatorship (BAP) (FHD-2023-10615).