Abstract
We investigate the α-effect and the turbulent transport of magnetic flux (γ-effect) by considering a turbulence driven by an isotropic helical forcing in the presence of a background large-scale shear flow. Due to shear flow, the turbulence is highly anisotropic. The effect of this shear-induced anisotropy on the structure of the electromotive force is computed selfconsistently. We show that for weak shear, magnetic pumping (γ-effect) appears, and theα-effect becomes highly anisotropic: the component of the α-effect in the direction of the shear is smaller than the one in the direction perpendicular to the shear with non-vanishing nondiagonal components. However, a sufficiently strong shear leads to severe quenching of the γ- and α-effects due to shear stabilisation.
| Original language | English |
|---|---|
| Pages (from-to) | 167-182 |
| Number of pages | 16 |
| Journal | Geophysical and Astrophysical Fluid Dynamics |
| Volume | 104 |
| Issue number | 2-3 |
| DOIs | |
| Publication status | Published - 30 Mar 2010 |
| Externally published | Yes |
Keywords
- Dynamo
- Shear flow
ASJC Scopus subject areas
- Computational Mechanics
- Astronomy and Astrophysics
- Geophysics
- Mechanics of Materials
- Geochemistry and Petrology