Transition from laminar to turbulent dynamo: the effect of varying Prandtl number

0533012 - GFÚ 2022 RIV GB eng J - Článek v odborném periodiku
Šimkanin, Ján - Kyselica, Juraj
Transition from laminar to turbulent dynamo: the effect of varying Prandtl number.
Geophysical and Astrophysical Fluid Dynamics. Roč. 115, č. 2 (2021), s. 192-206. ISSN 0309-1929. E-ISSN 1029-0419
Institucionální podpora: RVO:67985530
Klíčová slova: hydromagnetic dynamo * rotating spherical shell * thermal convection * turbulence * Prandtl number
Obor OECD: Physical geography
Impakt faktor: 1.590, rok: 2021
Způsob publikování: Omezený přístup
https://www.tandfonline.com/doi/abs/10.1080/03091929.2020.1804900?journalCode=ggaf20

We carry out numerical dynamo simulations in a spherical shell to assess the influence of varying Prandtl number on the morphology of the induced magnetic field in both cases when the convection is laminar and turbulent. We work in a regime of large magnetic Prandtl number (Pm = 3) due to computational constraints of the full three-dimensional numerical model. We consider dynamos driven by thermal convection in the regimes of small and unit Prandtl numbers. Unlike the laminar convection, in the turbulent regime the morphology of the induced magnetic fields depends only weakly on the Prandtl number. For both values of Pr considered the magnetic field is non-dipolar and small-scale. Together with the previous results of other authors, who found that the morphology of the magnetic field does not change substantially with Pr when Pm is small, the results of our study suggest that the induced magnetic field does not vary substantially with Pr regardless of the strength of the magnetic diffusion.
Trvalý link: http://hdl.handle.net/11104/0311513