The DRESDYN project: liquid metal experiments on dynamo action and magnetorotational instability

• Published in: Geophysical and astrophysical fluid dynamics Vol. 113; no. 1-2; pp. 51 - 70
• Main Authors: Stefani, F., Gailitis, A., Gerbeth, G., Giesecke, A., Gundrum, Th, Rüdiger, G., Seilmayer, M., Vogt, T.
• Format: Journal Article
• Language: English
• Published: Abingdon Taylor & Francis 04.03.2019; Taylor & Francis Ltd
• Subjects: Conducting fluids; Dynamo; Experiments; Fluid flow; Fluids; Galaxies; instabilities; Instability; Liquid sodium; Magnetic field; Magnetic fields; Metals; Planets; Sodium; Stellar magnetic fields
• ISSN: 0309-1929; 1029-0419
• DOI: 10.1080/03091929.2018.1501481

Magnetic fields of planets, stars and galaxies are generated by self-excitation in moving electrically conducting fluids. Once produced, magnetic fields can play an active role in cosmic structure formation by destabilising rotational flows that would be otherwise hydrodynamically stable. For a long time, both hydromagnetic dynamo action as well as magnetically triggered flow instabilities had been the subject of purely theoretical research. Meanwhile, however, the dynamo effect has been observed in large-scale liquid sodium experiments in Riga, Karlsruhe and Cadarache. In this paper, we summarise the results of liquid metal experiments devoted to the dynamo effect and various magnetic instabilities such as the helical and the azimuthal magnetorotational instability and the Tayler instability. We discuss in detail our plans for a precession-driven dynamo experiment and a large-scale Tayler-Couette experiment using liquid sodium, and on the prospects to observe magnetically triggered instabilities of flows with positive shear.