AUTHOR=Carpineti Marina , Castellini Stefano , Pogliani Andrea , Vailati Alberto 

TITLE=Transient Localized Rotating Structures in a Suspension of Highly Thermophilic Nanoparticles

JOURNAL=Frontiers in Physics

VOLUME=10

YEAR=2022

URL=https://www.frontiersin.org/journals/physics/articles/10.3389/fphy.2022.953067

DOI=10.3389/fphy.2022.953067

ISSN=2296-424X

ABSTRACT=<p>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 <italic>ψ</italic> = −3.5 heated from below. We show that transient localized states appear in the range of Rayleigh numbers 2200<inline-formula id="inf1"><mml:math id="m1" xmlns:mml="http://www.w3.org/1998/Math/MathML"><mml:mo>&lt;</mml:mo></mml:math></inline-formula>Ra<inline-formula id="inf2"><mml:math id="m2" xmlns:mml="http://www.w3.org/1998/Math/MathML"><mml:mo>&lt;</mml:mo></mml:math></inline-formula>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.</p>