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arXiv · 2504.15874

Scale invariance of intermittency in LES turbulence

B. Magacho·S. Thalabard·M. Buzzicotti·F. Bonaccorso·L Biferale·A. A. Mailybaev
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Abstract

Turbulent flows exhibit large intermittent fluctuations from inertial to dissipative scales, characterized by multifractal statistics and breaking the statistical self-similarity. It has recently been proposed that the Navier-Stokes turbulence restores a hidden form of scale invariance in the inertial interval when formulated for a dynamically (nonlinearly) rescaled quasi-Lagrangian velocity field. Here we show that such hidden self-similarity extends to the Large-Eddy Simulation (LES) approach in computational fluid dynamics (CFD). In particular, we show that classical subgrid-scale models, such as implicit or explicit Smagorinsky closures, respect the hidden scale invariance at all scales -- both resolved and subgrid. In the inertial range, they reproduce the hidden scale invariance of Navier-Stokes statistics. These properties are verified very accurately by numerical simulations and, beyond CFD, turn LES into a valuable tool for fundamental turbulence research.

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B. Magacho, S. Thalabard, M. Buzzicotti, F. Bonaccorso, L Biferale, A. A. Mailybaev. 2025-04-22. Scale invariance of intermittency in LES turbulence. https://arxiv.org/abs/2504.15874

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