Bibcode
Archontis, V.; Dorch, S. B. F.; Nordlund, Å.
Bibliographical reference
Astronomy and Astrophysics, v.397, p.393-399 (2003)
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1
2003
Journal
Citations
38
Refereed citations
31
Description
Numerical simulations of kinematic dynamo action in steady and
three-dimensional ABC flows are presented with special focus on the
difference in growth rates between cases with single and multiple
periods of the prescribed velocity field. It is found that the
difference in growth rate (apart from a trivial factor stemming from a
scaling of the rate of strain with the wavenumber of the velocity field)
is due to differences in the recycling of the weakest part of the
magnetic field. The single wavelength classical ABC-flow experiments
impose stronger symmetry requirements, which results in a suppression of
the growth rate. The experiments with larger wave number achieve growth
rates that are more compatible with the turn-over time scale by breaking
the symmetry of the resulting dynamo-generated magnetic field.
Differences in topology in cases with and without stagnation points in
the imposed velocity field are also investigated, and it is found that
the cigar-like structures that develop in the classical A=B=C dynamos
are replaced by ribbon structures in cases where the flow is without
stagnation points.