69th Annual Meeting of the APS Division of Fluid Dynamics (November 20, 2016 — November 22, 2016)

V0070: Libration-Driven Elliptical Instability Experiments in Ellipsoidal Shells

Authors

• Daphné Lemasquerier, Département des Sciences de la Terre, École Normale Supérieure de Lyon, Université de Lyon, Lyon, France
• Alexander Grannan, Departement of Earth, Planetary, and Space Sciences, University of California - Los Angeles, Los Angeles, CA, USA
• Benjamin Favier, Aix-Marseille Université, CNRS, École Centrale Marseille, IRPHE UMR 7342, 49 rue F. Joliot-Curie, 13013 Marseille, France
• David Cébron, CNRS, ISTerre, Université Grenoble Alpes, 38041 Grenoble, France
• Michael Le Bars, Aix-Marseille Université, CNRS, École Centrale Marseille, IRPHE UMR 7342, 49 rue F. Joliot-Curie, 13013 Marseille, France
• Jonathan Aurnou, Departement of Earth, Planetary, and Space Sciences, University of California - Los Angeles, Los Angeles, CA, USA

DOI: https://doi.org/10.1103/APS.DFD.2016.GFM.V0070

Planets and satellites can be subjected to physical libration, which consists in forced periodic variations in their rotation rate induced by gravitational interactions with nearby bodies. Many bodies librate, such as Mercury, the Moon, Europa, Io or Enceladus. Can such complex motions act to generate flows in low viscosity interior fluid layers such as subsurface oceans and metallic liquid cores? It is typically assumed in planetary geophysics that fluid motions must be affiliated with buoyancy anomalies. However, our lab-numerical experiments show that, even in a shell geometry which is more relevant to model planetary liquid layers, mechanically forced flows can also drive bulk filling turbulence.