Dynamo effect in parity-invariant flow with large and moderate separation of scales
Abstract
It is shown that non-helical (more precisely, parity-invariant) flows capable of sustaining a large-scale dynamo by the negative magnetic eddy diffusivity effect are quite common. This conclusion is based on numerical examination of a large number of randomly selected flows. Few outliers with strongly negative eddy diffusivities are also found, and they are interpreted in terms of the closeness of the control parameter to a critical value for generation of a small-scale magnetic field. Furthermore, it is shown that, for parity-invariant flows, a moderate separation of scales between the basic flow and the magnetic field often significantly reduces the critical magnetic Reynolds number for the onset of dynamo action.
Keywords
Cite
@article{arxiv.nlin/0012005,
title = {Dynamo effect in parity-invariant flow with large and moderate separation of scales},
author = {V. A. Zheligovsky and O. M. Podvigina and U. Frisch},
journal= {arXiv preprint arXiv:nlin/0012005},
year = {2009}
}
Comments
44 pages,11 figures, significantly revised version