Violent relaxation in two-dimensional flows with varying interaction range - Archive ouverte HAL
Article Dans Une Revue Physical Review E Année : 2015

Violent relaxation in two-dimensional flows with varying interaction range

Résumé

Understanding the relaxation of a system towards equilibrium is a longstanding problem in statistical mechanics. Here we address the role of long-range interactions in this process by considering a class of two-dimensional flows where the interaction between fluid particles varies with the distance as $\sim r^{\alpha-2}$ for $\alpha>0$. We find that changing $\alpha$ with a prescribed initial state leads to different flow patterns: for small $\alpha$, a coarsening process leads to the formation of a sharp interface between two regions of homogenized $\alpha$-vorticity; for large $\alpha$, the flow is attracted to a stable dipolar structure through a filamentation process. Assuming that the energy $E$ and the enstrophy $Z$ are injected at a typical scale smaller than the domain scale $L$, we argue that convergence towards the equilibrium state is expected when the parameter $\left(\frac{2\pi}{L}\right)^\alpha \frac{E}{Z}$ tends to one, while convergence towards a dipolar state occurs systematically when this parameter tends to zero. This suggests that weak long-range interacting systems are more prone to relax towards an equilibrium state than strong long-range interacting systems.
Fichier principal
Vignette du fichier
AlphaTurbArxivFinal.pdf (300.02 Ko) Télécharger le fichier
Origine Fichiers produits par l'(les) auteur(s)
Loading...

Dates et versions

hal-01136122 , version 1 (26-03-2015)
hal-01136122 , version 2 (23-06-2015)

Identifiants

Citer

A Venaille, Thierry Dauxois, S Ruffo. Violent relaxation in two-dimensional flows with varying interaction range. Physical Review E , 2015, 92 (011001(R)). ⟨hal-01136122v2⟩
93 Consultations
178 Téléchargements

Altmetric

Partager

More