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Gyroflow
A rotating platform for geophysical fluid dynamics


French version

Members: M. Brunet, F. Moisy, P.-P. Cortet

Previous members: A. Campagne, J. Boisson, B. Gallet, C. Lamriben, N. Machicoane, M. Rabaud

Present and past collaborations : T. Dauxois (ENS Lyon), B. Gallet (CEA Saclay), L.R.M. Maas (Univ. Utrecht), B. Voisin (LEGI), D. Cébron (ISTerre), P. Billant et J.-M. Chomaz (LadHyX)



What is Gyroflow?

Gyroflow is a rotating platform designed for research in geophysical fluid dynamics. This platform, 2 m in diameter, can rotate up to 1 ton of experiment and instruments, at a maximum angular velocity of 30 rpm.

It is installed in the laboratory FAST (Fluides, Automatique et Systèmes Thermiques), in Orsay (France), since september 2009.


The Gyroflow platform. Particle Image Velocimetry measurements are performed using the camera (right, in blue), and the pulsed laser (left, in black).



What is a geophysical flow?

Geophysical flows are flows dominated by the effects of rotation (through the Coriolis force) and stratification (through the buoyancy force due to a density gradient).

Large scale ocean currents and atmospheric circulations provide illustrations of the remarkable features of geophysical flows: quasi-two-dimensionality and the presence of large scale coherent vortices.

Geophysical flows are also present in gaseous planets - e.g., Jupiter's red spot -, in stars, or in the liquid cores of planets.


Two examples of geophysical flows: two cyclones in the South of Island, and the great red spot of Jupiter (source: NASA).



What is the effect of the Coriolis force on a flow

The Coriolis force deflects the trajectory of fluid particles, in a way similar to the effect of a magnetic field on charged particles. In an incompressible fluid, the resulting circular trajectory gives rise to an anisotropic propagative wave, called an inertial wave.

When the flow is turbulent, the effect of the Coriolis force is complex: the Turbulence becomes anisotropic with a strong tendency toward a 2D state, vertically invariant along the rotation axis. Large scales may be dominated by the effect of rotation, whereas small scales are not, because of their fast dynamics compared to the rotation rate. Moreover, at the large scales, the non-linear interactions between inertial waves can in certain regimes drive the turbulence dynamics, building a regime of "Wave turbulence".

Rotating turbulence experiments

The Gyroflow rotating platform is an experimental tool for the study of the fundamental processes emerging from the interaction between global rotation and fluid dynamics. It is first of all dedicated to the study of turbulence under rotation as in the two experiments illustrated below:

  • A decaying turbulence experiment, in which turbulence is generated by the rapid translation of a grid in the fluid
  • A forced turbulence experiment, in which vortex dipole generators continuously inject energy in the center of the flow.


Grid-generated decaying turbulence experiment on the rotating platform (october 2009).



Forced turbulence experiment, in which vortex dipole generators continuously inject energy in the center of the flow (february 2013).


Acknowledgments

The activities on the Gyroflow platform are currently supported by the Agence Nationale de la Recherche through grant ANR-17-CE30-0003 DisET (2018-2022).



Large audience papers

  • A liquid Foucault pendulum, CNRS international magazine, 27 (october 2012).
  • Un pendule de Foucault version liquide, CNRS Le journal, 268 (september-october 2012).
  • Un pendule de Foucault fluide
    J. Boisson, D. Cébron, F. Moisy, P.-P. Cortet, Reflets de la Physique 31 22-23 (2012).
    [Abstract | PDF]
  • Et pourtant elle tourne...
    F. Moisy, C. Lamriben, P.-P. Cortet, M. Rabaud, Plein Sud Spécial Recherche 2010-2011, 28-37 (2011).
    [PDF]

Read more


Publications

The following papers are based on data obtained from the platform Gyroflow.

  • Wake of inertial waves of a horizontal cylinder in horizontal translation
    N. Machicoane, V. Labarre, B. Voisin, F. Moisy, P.-P. Cortet, Phys. Rev. Fluids 3 034801(2018)
    [Abstract | PDF]
  • Two-dimensionalization of the flow driven by a slowly rotating impeller in a rapidly rotating fluid
    N. Machicoane, F. Moisy, P.-P. Cortet, Phys. Rev. Fluids 1, 073701 (2016)
    [Abstract | PDF]
  • Turbulent drag in a rotating frame
    A. Campagne, N. Machicoane, B. Gallet, P.-P. Cortet, F. Moisy, J. Fluid Mech. 794, R5 (2016)
    [Abstract | PDF]
  • Influence of the multipole order of the source on the decay of an inertial wave beam in a rotating fluid
    N. Machicoane, P.-P. Cortet, B. Voisin, F. Moisy, Phys. Fluids 27, 066602 (2015)
    [Abstract | PDF]
  • Disentangling inertial waves from eddy turbulence in a forced rotating turbulence experiment
    A. Campagne, B. Gallet, F. Moisy, P.-P. Cortet, Phys. Rev. E 91, 043016 (2015)
  • [Abstract | PDF]
  • Structure and dynamics of rotating turbulence: a review of recent experimental and numerical results
    F.S. Godeferd, F. Moisy, Applied Mechanics Reviews 67, 030802 (2015)
    [Abstract | PDF]
  • Scale-dependent cyclone-anticyclone asymmetry in a forced rotating turbulence experiment
    B. Gallet, A. Campagne, P.-P. Cortet, F. Moisy, Phys. Fluids 26 035108 (2014).
    [Abstract | PDF]
  • Direct and inverse energy cascades in a forced rotating turbulence experiment
    A. Campagne, B. Gallet, F. Moisy, P.-P. Cortet, Phys. Fluids 26, 125112 (2014)
    [Abstract | PDF]
  • Inertial waves and modes excited by the libration of a rotating cube
    J. Boisson, C. Lamriben, L.R.M. Maas, P.-P. Cortet, F. Moisy, Phys. Fluids 24, 076602 (2012).
    [Abstract | PDF | movies]
  • Earth rotation prevents exact solid body rotation of fluids in the laboratory
    J. Boisson, D. Cébron, F. Moisy, P.-P. Cortet, EPL 98, 59002 (2012).
    [Abstract | PDF]
  • Experimental evidence of a triadic resonance of plane inertial waves in a rotating fluid
    G. Bordes, F. Moisy, T. Dauxois, P.-P. Cortet, Phys. Fluids 24, 014105 (2012).
    [Abstract | PDF]
  • Direct measurements of anisotropic energy transfers in a rotating turbulence experiment
    C. Lamriben, P.-P. Cortet, F. Moisy, Phys. Rev. Lett. 107, 024503 (2011).
    [Abstract | PDF]
  • Excitation of inertial modes in a closed grid turbulence experiment under rotation
    C. Lamriben, P.-P. Cortet, F. Moisy, L. Maas, Phys. Fluids 23, 015102 (2011).
    [Abstract | PDF]
  • Viscous spreading of an inertial wave beam in a rotating fluid
    P.-P. Cortet, C. Lamriben, F. Moisy, Phys. Fluids 22, 086603 (2010).
    [Abstract | PDF]