Nature of the alpha effect in magnetohydrodynamics

被引：72

作者：

Seehafer, N

机构：

[1] Max-Planck-Gruppe Nichtlineare Dynamik, Universität Potsdam, Potsdam, D-14415

来源：

PHYSICAL REVIEW E | 1996年 / 53卷 / 01期

关键词：

D O I：

10.1103/PhysRevE.53.1283

中图分类号：

O35 [流体力学]; O53 [等离子体物理学];

学科分类号：

070204 ; 080103 ; 080704 ;

摘要：

It is shown that the alpha effect of mean-field magnetohydrodynamics, which consists of the generation of a mean electromotive force along the mean magnetic field by turbulently fluctuating parts of velocity and magnetic field, is equivalent to the simultaneous generation of both turbulent and mean-field magnetic helicities, the generation rates being equal in magnitude and opposite in sign. In the particular case of statistically stationary and homogeneous fluctuations this implies that the alpha effect can increase the energy in the mean magnetic field only under the condition that magnetic helicity is also accumulated there.

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页码：1283 / 1286

页数：4

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