Forcing-dependent stability of steady states in a turbulent swirling flow

TL;DR

This paper investigates how different forcing conditions affect the stability of steady turbulent states in a swirling flow, revealing regimes similar to low-dimensional systems and suggesting broader implications for out-of-equilibrium systems.

Contribution

It demonstrates the forcing-dependent stability of turbulent states and proposes an analogy with ensemble inequivalence in long-range interacting systems.

Findings

Forcing conditions alter the stability of steady states.

Dynamical regimes resemble low-dimensional systems.

Potential applicability to other turbulent flows.

Abstract

We study the influence of the forcing on the steady turbulent states of a von K\'arm\'an swirling flow, at constant impeller speed, or at constant torque. We find that the different forcing conditions change the nature of the stability of the steady states and reveal dynamical regimes that bear similarities with low-dimensional systems. We suggest that this forcing dependence may be an out- of-equilibrium analogue of the ensemble inequivalence, valid for long-range interacting statistical systems, and that it may be applicable to other turbulent systems.