https://doi.org/10.1140/epjp/s13360-025-06366-1
Regular Article
Experimental investigation of buoyancy-driven convective heat transfer of Ag/Fe3O4 hybrid nanofluid inside an enclosure
Department of Mechanical Engineering, National Institute of Technology Srinagar, 190006, Hazratbal, Srinagar, J&K, India
Received:
30
January
2025
Accepted:
24
April
2025
Published online:
21
May
2025
With their superior heat transfer capabilities, hybrid nanofluids are gaining attention as advanced fluids, leveraging the enhanced properties of their individual components. This research investigates the combined effects of Ag and Fe3O4 nanoparticles for improving the thermal characteristics of traditional heat transfer fluids like ethylene glycol. Using a two-step methodology, the hybrid nanofluids are prepared and then characterized for their thermal conductivity and viscosity. The thermal conductivity of Ag/Fe3O4 shows an increase of up to 9.84% with respect to the base fluid. Similarly, viscosity rises with nanoparticle concentration with the highest viscosity increase of 23% at 0.2% particle loading, while a smaller enhancement of 2.05% occurs at 0.01% concentration. Zeta potential analysis indicated excellent dispersion stability, with values exceeding 30 mV, although stability decreased at higher concentrations due to particle agglomeration. An experimental study on buoyancy-driven convective heat transfer is conducted to evaluate the nanoparticle doping effectiveness. A cubic cavity filled with the hybrid nanofluid is used, and the heat transfer performance is measured by the Nusselt number and heat transfer coefficient. The results show significant improvements in both parameters compared to the base fluid. The Nusselt number increases by up to 7.03%, and the heat transfer coefficient reaches a maximum increase of 12.4% at an optimal nanoparticle concentration of 0.15%. These findings highlight the importance of optimizing nanoparticle concentration for enhanced heat transfer performance in practical applications.
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© The Author(s), under exclusive licence to Società Italiana di Fisica and Springer-Verlag GmbH Germany, part of Springer Nature 2025
Springer Nature or its licensor (e.g. a society or other partner) holds exclusive rights to this article under a publishing agreement with the author(s) or other rightsholder(s); author self-archiving of the accepted manuscript version of this article is solely governed by the terms of such publishing agreement and applicable law.