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Titel |
On the origin of time-dependent behaviour in a barotropically unstable shear layer |
VerfasserIn |
W.-G. Früh, A. H. Nielsen |
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 ; 10, no. 3 ; Nr. 10, no. 3, S.289-302 |
Datensatznummer |
250007998
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Publikation (Nr.) |
copernicus.org/npg-10-289-2003.pdf |
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Zusammenfassung |
An experimental
study on the instability of a detached Stewartson layer, using an annular,
rotating tank with flat, rigid upper and lower boundaries, showed an
instability to steady vortices at a critical Reynolds number, arranged in
a global mode structure along the shear layer. Increasing the Reynolds
number resulted in successive transitions to lower modes where
time-dependent behaviour was only found for flows with three or less
vortices. Previous numerical simulations of a related experiment, using a
two-dimensional spectral model of the quasi-geostrophic vorticity equation
incorporating Ekman forcing and viscous dissipation, suggested that the
boundary conditions at the inner cylinder of the domain could
significantly affect the interior flow by the generation and shedding of
vorticity at this inner boundary. A comparison of the numerical results
with experimental data suggests that the rise of time-dependent behaviour
is due to vorticity generation at the inner domain boundary. |
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