Synchronization of Chaos in Fully-Developed Turbulence

TL;DR

This paper demonstrates that in three-dimensional turbulence, small-scale chaotic motions are synchronized with larger scales, allowing full recovery of sub-Kolmogorov modes from large-scale data using numerical simulations.

Contribution

It shows that small-scale turbulence modes are synchronized with larger scales, enabling their reconstruction from large-scale dynamics in numerical simulations.

Findings

Small-scale modes below 20 Kolmogorov lengths are slaved to larger scales.

Full small-scale dynamics can be recovered from large-scale solutions with high precision.

Synchronization rate scales with Kolmogorov dissipation time, with weak intermittency corrections.

Abstract

We investigate chaos synchronization of small-scale motions in the three-dimensional turbulent energy cascade, via pseudo-spectral simulations of the incompressible Navier-Stokes equations. The modes of the turbulent velocity field below about 20 Kolmogorov dissipation lengths are found to be slaved to the chaotic dynamics of larger-scale modes. The dynamics of all dissipation-range modes can be recovered to full numerical precision by solving small-scale dynamical equations with the given large-scale solution as an input, regardless of initial condition. The synchronization rate exponent scales with the Kolmogorov dissipation time-scale, with possible weak corrections due to intermittency. Our results suggest that all sub-Kolmogorov length modes should be fully recoverable from numerical simulations with standard, Kolmogorov-length grid resolutions.