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Titel |
Formation of vortex clusters on a sphere |
VerfasserIn |
V. Pavlov, D. Buisine, V. Goncharov |
Medientyp |
Artikel
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Sprache |
Englisch
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ISSN |
1023-5809
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Digitales Dokument |
URL |
Erschienen |
In: Nonlinear Processes in Geophysics ; 8, no. 1/2 ; Nr. 8, no. 1/2, S.9-19 |
Datensatznummer |
250005285
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Publikation (Nr.) |
copernicus.org/npg-8-9-2001.pdf |
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Zusammenfassung |
This paper applies
the Hamiltonian Approach (HA) to two-dimensional motions of incompressible
fluid in curvi-linear coordinates, in particular on a sphere. The HA has
been used to formulate governing equations of motion and to interpret the
evolution of a system consisting of N localized two-dimensional vortices
on a sphere. If the number of vortices N is large,
N ~ 102 - 103 , a small number of vortex
collective structures (clusters) is formed. The surprise is that a
quasi-final state does not correspond to completely disorganized
distribution of vorticity. Numerical analysis has been carried out for
initial conditions taken in the form of a few axisymmetric
chains of point vortices distributed initially in fixed latitudes. The
scheme of Runge-Kutta of 4th order has been used for simulating an
evolution of resulting flows. The numerical analysis shows that the
Kelvin-Helmholtz instability appears immediately formating initial
disorganized structures which are developed and finally "bursted".
The system evolves to a few separated vortex "spots" which exist
sufficiently for a long time. |
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