Vortices as Brownian particles in turbulent flows.
Sci Adv
; 6(34): eaaz1110, 2020 Aug.
Article
em En
| MEDLINE
| ID: mdl-32875101
ABSTRACT
Brownian motion of particles in fluid is the most common form of collective behavior in physical and biological systems. Here, we demonstrate through both experiment and numerical simulation that the movement of vortices in a rotating turbulent convective flow resembles that of inertial Brownian particles, i.e., they initially move ballistically and then diffusively after certain critical time. Moreover, the transition from ballistic to diffusive behaviors is direct, as predicted by Langevin, without first going through the hydrodynamic memory regime. The transitional timescale and the diffusivity of the vortices can be collapsed excellently onto a master curve for all explored parameters. In the spatial domain, however, the vortices exhibit organized structures, as if they are performing tethered random motion. Our results imply that the convective vortices have inertia-induced memory such that their short-term movement can be predicted and their motion can be well described in the framework of Brownian motions.
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Base de dados:
MEDLINE
Idioma:
En
Revista:
Sci Adv
Ano de publicação:
2020
Tipo de documento:
Article
País de afiliação:
China