Conditional vorticity budget of coherent and incoherent flow contributions in fully developed homogeneous isotropic turbulence

TL;DR

This paper analyzes the vorticity budget in turbulence by decomposing flow into coherent and incoherent parts using wavelets, revealing differences from Fourier-based methods and linking flow structures to statistical properties.

Contribution

It introduces a wavelet-based method to distinguish coherent and incoherent vorticity contributions and compares these with Fourier decomposition results in turbulence analysis.

Findings

Wavelet decomposition effectively separates flow contributions.

Significant differences found between wavelet and Fourier analyses.

Flow structures influence statistical vorticity budgets.

Abstract

We investigate the conditional vorticity budget of fully developed three-dimensional homogeneous isotropic turbulence with respect to coherent and incoherent flow contributions. The Coherent Vorticity Extraction based on orthogonal wavelets allows to decompose the vorticity field into coherent and incoherent contributions, of which the latter are noise-like. The impact of the vortex structures observed in fully developed turbulence on statistical balance equations is quantified considering the conditional vorticity budget. The connection between the basic structures present in the flow and their statistical implications is thereby assessed. The results are compared to those obtained for large- and small-scale contributions using a Fourier decomposition, which reveals pronounced differences.