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Experimental investigation of Rayleigh-Bénard convection patterns in low-concentration nanofluids

Alexandre Vierron* and Chérifa Abid

  • *Contact author: alexandrevierron@ikmail.com
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Phys. Rev. Fluids 11, 013505 – Published 23 January, 2026

DOI: https://doi.org/10.1103/48gl-1b2b

Abstract

This study investigates the influence of titanium dioxide (TiO2) nanoparticles suspended in water on convection cells and heat transfer dynamics. To this end, a Rayleigh-Bénard experimental study was conducted for a water-TiO2 nanofluid (<0.02% wt) in a cylindrical cavity with a diameter to height aspect ratio of 16. A shadowgraph was used to visualize the spatial and temporal evolution of convection cells in a Rayleigh regime (<104), well suited for observing transitions and stability in flow patterns. The observations show that both colloidal stability and nanoparticle sedimentation strongly affect the evolution of convection patterns and heat transfer. These experiments qualitatively demonstrate that TiO2 nanoparticles can enhance heat transfer under convective conditions, as inferred from the observed changes in convection cell pattern and flow organization. While nanofluids are typically designed to maximize colloidal stability, minimize agglomeration, and prevent sedimentation, our results challenge this paradigm by showing that sedimentation plays a key role in intensifying heat transport.

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Phys. Rev. Fluids 11, 013505– Published 23 January, 2026
  • Received 15 November 2024
  • Accepted 21 November 2025
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Published by the American Physical Society under the terms of the Creative Commons Attribution 4.0 International license. Further distribution of this work must maintain attribution to the author(s) and the published article's title, journal citation, and DOI.

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