Antidynamo theorems for non-radial flows
作者:
D.J. Ivers,
R.W. James,
期刊:
Geophysical & Astrophysical Fluid Dynamics
(Taylor Available online 1988)
卷期:
Volume 40,
issue 1-2
页码: 147-163
ISSN:0309-1929
年代: 1988
DOI:10.1080/03091928808208823
出版商: Taylor & Francis Group
关键词: Antidynamo theorems;dynamo theory
数据来源: Taylor
摘要:
Magnetic fields induced by non-radial compressible flows (vr≡ 0, ∇·v≢ 0) in spherical conductors are shown to decay, or at least be incapable of indefinite amplification. The results herein supplement previously established antidynamo results for purely toroidal flows (vr≡ ∇·v≡ 0), with the allowance of compressibility necessitating new proofs with different senses of field decay. The poloidal field variabler·Bdecays in a global sense with an undetermined decay rate. A pointwise bound is established that limits the ultimate strength of the toroidal field scalar T, and shows that if the poloidal field is negligible and the conductivity uniform then the toroidal field decays to zero at no slower than the poloidal free-decay rate π2.
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