Subcritical transition to turbulence of a precessing flow in a cylindrical vessel

TL;DR

This study experimentally investigates the transition to turbulence in a precessing cylindrical flow, revealing a subcritical transition with hysteresis and turbulence lifetime dependence on control parameters.

Contribution

It provides new experimental evidence of subcritical turbulence transition and hysteresis in precessing cylindrical flows, highlighting turbulence lifetime behavior.

Findings

Transition from laminar to turbulence is subcritical with hysteresis.

Turbulence can spontaneously relaminarize after finite duration.

Turbulence lifetime increases sharply near the threshold.

Abstract

The transition to turbulence in a precessing cylindrical vessel is experimentally investigated. Our measurements are performed for a { nearly-resonant} configuration with an initially laminar flow dominated by an inertial mode with azimuthal wave number $m=1$ superimposed on a solid body rotation. By increasing the precession ratio, we observe a transition from the laminar to a non-linear regime, which then breakdowns to turbulence for larger precession ratio. Our measurements show that the transition to turbulence is subcritical, with a discontinuity of the wall-pressure and the power consumption at the threshold $\epsilon_{LT}$. The turbulence is self-sustained below this threshold, describing a bifurcation diagram with a hysteresis. In this range of the control parameters, the turbulent flows can suddenly collapse after a finite duration, leading to a definitive relaminarization of the flow. The average lifetime $\langle \tau \rangle$ of the turbulence increases rapidly when $\epsilon$ tends to $\epsilon_{LT}$.