Statut  Confirmé 
Série  COLLOQUIUMENS 
Domaines  physics 
Date  Mercredi 21 Fevrier 2024 
Heure  13:30 
Institut  DPTPHYSENS 
Salle  ConfIV (E244)  Dépt de Physique de l'ENS  24 rue Lhomond 75005 PARIS 
Nom de l'orateur  Vitelli 
Prenom de l'orateur  Vicenzo 
Addresse email de l'orateur  
Institution de l'orateur  
Titre  Odd Turbulence 
Résumé  Fully developed turbulence is a universal and scaleinvariant chaotic state characterized by an energy cascade from large to small scales where the cascade is eventually arrested by dissipation. In this talk, we discuss how to harness these seemingly structureless turbulent cascades to generate patterns. Pattern formation entails a process of wavelength selection, which can typically be traced to the linear instability of a homogeneous state. By contrast, the mechanism we propose here is fully nonlinear. It is triggered by a nondissipative arrest of turbulent cascades: energy piles up at an intermediate scale, which is neither the system size nor the smallest scales at which energy is dissipated. Using a combination of theory and largescale simulations, we show that the tunable wavelength of these cascadeinduced patterns can be set by a nondissipative transport coefficient called odd or gyro viscosity. This nondissipative viscosity is ubiquitous in chiral systems ranging from plasma and bioactive media to quantum fluids. Cascadeinduced patterns could also occur in natural systems including atmospheric flows, stellar plasma such as the solar wind, as well as the pulverization of objects or the coagulation of droplets where mass rather than energy cascades. 
Numéro de preprint arXiv  
Commentaires  
Fichiers attachés 
Pour obtenir l' affiche de ce séminaire : [ Postscript  PDF ]

[ English version ] 