Frontiers in Physics (Jul 2022)

Transient Localized Rotating Structures in a Suspension of Highly Thermophilic Nanoparticles

  • Marina Carpineti,
  • Stefano Castellini,
  • Andrea Pogliani,
  • Alberto Vailati

DOI
https://doi.org/10.3389/fphy.2022.953067
Journal volume & issue
Vol. 10

Abstract

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A thermophilic suspension of nanoparticles heated from below exhibits a complex stability diagram determined by the competition between the stabilizing flux of nanoparticles induced by thermophoresis and the destabilizing flux determined by thermal convection. We investigate Rayleigh-Bénard convection in a suspension of highly thermophilic nanoparticles with large negative separation ratio ψ = −3.5 heated from below. We show that transient localized states appear in the range of Rayleigh numbers 2200<Ra<3000. These states rotate rapidly around their axis and gradually shrink in size until the system returns in a purely conductive state. We discuss how these states are originated by the travelling waves arising from the competition between Rayleigh-Bénard convection and the solutal stabilisation of the sample.

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