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Titel |
Turbulence: mechanics and structure of anomalous scaling |
VerfasserIn |
S. N. Gordienko, S. S. Moiseev |
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. 4/5 ; Nr. 8, no. 4/5, S.197-200 |
Datensatznummer |
250005293
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Publikation (Nr.) |
copernicus.org/npg-8-197-2001.pdf |
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Zusammenfassung |
As the finite
correlation time of a force driving turbulence is taken into account, a
new, dimensionless parameter occurs in the theory of turbulence. This new
parameter is responsible for two different mechanisms of formation of
anomalous spectra. The first mechanism is related to the change of a
governing parameter, which defines the spectrum of turbulent fluctuation.
The second mechanism is associated with spontaneous formation of
characteristic scales that differ parametrically from the scale of the
external force. The last mechanism can explain the intermittent structure
of turbulent flows. The appropriate discrete set of the possible
characteristic scales and anomalous spectra has been calculated. The
results give a new insight into the concept of universality: there is a
set of universal power laws, although occurrence in the spectrum segments
described by one or another power law from this set depends on the
dimensionless parameter mentioned above. It is noted that for the broad
class of geophysical flows, the new dimensionless parameter is connected
with the so-called degree of turbulence, which guarantees that the
smallness of this parameter, as the degree of turbulence is usually small
enough. That explains the important role of the Kolmogorov spectrum in
geophysical applications. |
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