Bifurcations of a large scale circulation in a quasi-bidimensional turbulent flow

TL;DR

This paper experimentally investigates the bifurcations of a large-scale circulation in a turbulent flow with periodic forcing, focusing on transitions within turbulence linked to changes in the flow's amplitude distribution.

Contribution

It provides new insights into the bifurcation phenomena within turbulent regimes and models the probability density functions of the flow amplitude.

Findings

Flow becomes turbulent through symmetry-breaking bifurcations.

Transitions within turbulence involve changes in the PDF shape of flow amplitude.

The study offers a model for the PDF shape during bifurcations.

Abstract

We report the experimental study of the bifurcations of a large-scale circulation that is formed over a turbulent flow generated by a spatially periodic forcing. After shortly describing how the flow becomes turbulent through a sequence of symmetry breaking bifurcations, we focus our study on the transitions that occur within the turbulent regime. They are related to changes in the shape of the probability density function (PDF) of the amplitude of the large scale flow. We discuss the nature of these bifurcations and how to model the shape of the PDF.