Mean-field and fluctuation analyses of a forced turbulence simulated by the lattice Boltzmann method

TL;DR

This paper uses lattice Boltzmann simulations to analyze forced turbulence, confirming Kolmogorov's scaling and Taylor's hypothesis, and revealing the role of coherent vortices in sustaining power-law velocity correlations.

Contribution

It provides the first simulation-based verification of Kolmogorov's scaling and Taylor's hypothesis in Navier-Stokes turbulence using lattice Boltzmann methods.

Findings

Verified Kolmogorov's scaling in simulation

Confirmed Taylor's hypothesis in turbulence

Identified coherent vortices as key to velocity correlations

Abstract

On the basis of the lattice Boltzmann method we have done a numerical experiment of a forced turbulence in real space and time. Our new findings are summarized into two points. First in the analysis of the mean-field behavior of the velocity field using the exit-time statistics we have verified Kolmogorov's scaling and Taylor's hypothesis for the first time in the simulation for the Navier-Stokes equation. Second in the analysis of the intermittent velocity fluctuations using a non-equilibrium probability distribution function and the wavelet denoising we have clarified that the coherent vortices sustain the power-law velocity correlation in the non-equilibrium state.