Molecular hints of two-step transition to convective flow via streamline percolation
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Show full item recordEditorial
American Physical Society
Date
2022-07-28Referencia bibliográfica
L. Garrido and P. I. Hurtado. Molecular hints of two-step transition to convective flow via streamline percolation. Phys. Rev. E 106, 014144 [https://doi.org/10.1103/PhysRevE.106.014144]
Sponsorship
Federación Española de Enfermedades Raras; Ministerio de Economía y Competitividad FIS2017-84256-P; European Regional Development Fund MICIN/AEI/10.13039/501100011033, PID2020-113681GB-I00; Junta de Andalucía A-FQM-175-UGR18Abstract
Convection is a key transport phenomenon important in many different areas, from hydrodynamics and ocean
circulation to planetary atmospheres or stellar physics. However, its microscopic understanding still remains
challenging. Here we numerically investigate the onset of convective flow in a compressible (non-Oberbeck-
Boussinesq) hard disk fluid under a temperature gradient in a gravitational field.We uncover a surprising two-step
transition scenario with two different critical temperatures. When the bottom plate temperature reaches a first
threshold, convection kicks in (as shown by a structured velocity field) but gravity results in hindered heat
transport as compared to the gravity-free case. It is at a second (higher) temperature that a percolation transition
of advection zones connecting the hot and cold plates triggers efficient convective heat transport. Interestingly,
this picture for the convection instability opens the door to unknown piecewise-continuous solutions to the
Navier-Stokes equations.