Distributed chaos and helicity in turbulence

TL;DR

This paper investigates how distributed chaos driven by helicity influences complex turbulent flows, showing that helical distributed chaos underpins the interaction between large-scale structures and small-scale turbulence, with practical implications for plasma confinement.

Contribution

It introduces the concept of helical distributed chaos as a fundamental basis for understanding complex turbulence involving helicity and demonstrates its relevance in various flow scenarios.

Findings

Helical distributed chaos is present in diverse turbulent flows.

Helicity influences the structure and behavior of turbulence.

Helical chaos improves particle confinement in plasma devices.

Abstract

The distributed chaos driven by Levich-Tsinober (helicity) integral: $I=\int \langle h({\bf x},t)~h({\bf x}+{\bf r}, t)\rangle d{\bf r}$ has been studied. It is shown that the helical distributed chaos can be considered as basis for complex turbulent flows with interplay between large-scale coherent structures and small-scale turbulence, such as Cuette-Taylor flow, wake behind cylinder and turbulent flow in the Large Plasma Device (LAPD) with inserted limiters. In the last case appearance of the helical distributed chaos, caused by the limiters, results in improvement of radial particle confinement.