American Institute of Physics | 2017 May 23
A model based on the Von-Kármán-Sodium dynamo experiment investigates how turbulence and impeller material affect the magnetic field
[img3="The evolution of the whirl of the vortex, as the model progresses from 37 seconds and 42 seconds. Increasing turbulence in the flow causes variations in the whirl and leads to periodic cycling of the magnetic field, such as is observed with the sun. Credit: Varela/Brun/Dubrulle/Nore"]https://publishing.aip.org/sites/defaul ... ed-WEB.jpg[/img3][hr][/hr]The massive, churning core of conducting liquids in stars and some planets creates a dynamo that generates the planetary body’s magnetic field. Researchers aim to better understand these dynamos through computer simulations and by recreating them in the laboratory using canisters of rapidly spinning, liquid sodium.
A new simulation based on the von-Kármán-Sodium (VKS) dynamo experiment ... takes a closer look at how the liquid vortex created by the device generates a magnetic field. Researchers investigated the effects of fluid resistivity and turbulence on the collimation of the magnetic field, where the vortex becomes a focused stream. ...
The study is the first to examine the flow inside the churning blades at high resolution, and can offer ways to improve laboratory dynamos so that they more accurately recreate stellar astronomical observations. ...
Effects of Turbulence, Resistivity and Boundary Conditions on Helicoidal Flow Collimation:
Consequences for the Von-Kármán-Sodium Dynamo Experiment - Jacobo Varela et al
- Physics of Plasmas 24(05):3518 (May 2017) DOI: 10.1063/1.4983313