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| 1. |
Local turbulence in the Earth's core |
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Geophysical & Astrophysical Fluid Dynamics,
Volume 55,
Issue 2,
1990,
Page 71-87
S.I. Braginsky,
V.P. Meytlis,
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摘要:
It is shown that in the Earth's core, where the geodynamo is at work (and is supplied with energy by the prevailing unstable density stratification), a buoyancy instability of a local character exists which is highly supercritical. This instability results in fully developed turbulence dominated by small scale vortices. The influence of the Earth's rotation and of the magnetic field produced by the geodynamo makes this small scale turbulence highly anisotropic. A qualitative picture of this local anisotropic turbulence is devised and the main parameters characterizing it are estimated. Expressions for the turbulent diffusivity are developed and discussed.
ISSN:0309-1929
DOI:10.1080/03091929008203556
出版商:Taylor & Francis Group
年代:1990
数据来源: Taylor
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| 2. |
Flow separation and unsteadiness in a rotating sliced cylinder |
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Geophysical & Astrophysical Fluid Dynamics,
Volume 55,
Issue 2,
1990,
Page 89-115
Anne Becker,
MichaelA. Page,
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PDF (2080KB)
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摘要:
The rotating sliced cylinder model has its origins in simulations of the large scale wind-driven ocean circulation. The model consists of a rotating circular cylinder with a sloping planar base and a lid which rotates at a rate slightly different from that of the background rotation. Numerical models for the inviscid flow, the boundary-layer flow and the viscous flow equations in this configuration are described and the flow patterns produced by them are compared. Laboratory experiments were also performed and the results are presented as validation of the numerical models. The unsteadiness of the flow in some parameter régimes which was noted by other authors (Beardsley, 1969, 1973a, b and Beardsley and Robbins, 1975) appears to be caused by instability of the separated boundary-layer flow. The separated flow has some unique features due to the effect of the driving force exerted on the flow by the rotating lid and these are also described.
ISSN:0309-1929
DOI:10.1080/03091929008203557
出版商:Taylor & Francis Group
年代:1990
数据来源: Taylor
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| 3. |
On a model of bottom erosion by dense water steady veins |
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Geophysical & Astrophysical Fluid Dynamics,
Volume 55,
Issue 2,
1990,
Page 117-135
A. Caserta,
E. Mieli,
E. Salusti,
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PDF (556KB)
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摘要:
In order to discuss the one-dimensional bottom motion of a vein of dense water over a mild slope and underlying upper water at rest, we obtain an integrodifferential partial nonlinear equation in the vein thickness. Some elementary solutions and their physical meaning are discussed.
ISSN:0309-1929
DOI:10.1080/03091929008203558
出版商:Taylor & Francis Group
年代:1990
数据来源: Taylor
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