Punctuated vortex coalescence and discrete scale invariance in two-dimensional turbulence
Publikation: Bidrag til tidsskrift › Tidsskriftartikel › Forskning › fagfællebedømt
We present experimental evidence and theoretical arguments showing that the time-evolution of freely decaying two-dimensional (2D) turbulence is governed by a discrete time scale invariance rather than a continuous time scale invariance. Physically, this reflects that the time-evolution of the merging of vortices is not smooth but punctuated, leading to a preferred scale factor and, as a consequence, to log-periodic oscillations. From a thorough analysis of freely decaying 2D turbulence experiments, we show that the number of vortices, their radius and separation display log-periodic oscillations as a function of time with an average log-frequency of ≈ 4-5 corresponding to a preferred scaling ratio of ≈ 1.2-1.3.
Originalsprog | Engelsk |
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Tidsskrift | Physica D: Nonlinear Phenomena |
Vol/bind | 138 |
Udgave nummer | 3-4 |
Sider (fra-til) | 302-315 |
Antal sider | 14 |
ISSN | 0167-2789 |
DOI | |
Status | Udgivet - 15 apr. 2000 |
ID: 332620645