Institut für Geophysik Geschäftsführender Direktor:
Prof. Dr. Ulrich Hansen

Corrensstraße 24 48149 Münster
Tel.: +49 251 83-33590
Fax: +49 251 83-36100

Statistical analysis of global wind dynamics in vigorous Rayleigh-Bénard Convection

K. Petschel, M. Wilczek, M. Breuer, R. Friedrich and U. Hansen

 


Experimental and numerical studies of thermal convection have shown that sufficiently vigorous convective
flows exhibit a large-scale thermal wind component sweeping along small-scale thermal boundary layer
instabilities. A characteristic feature of these flows is an intermittent behavior in the form of irregular reversals
in the orientation of the large-scale circulation. There have been several attempts toward a better understanding
and description of the phenomenon of flow reversals, but so far most of these models are based on a statistical
analysis of few-point measurements or on simplified theoretical assumptions. The analysis of long-term data
sets (>5 × 10^5 turnover times τt = d/urms) obtained by numerical simulations of turbulent two-dimensional
Rayleigh-B´enard convection allows us to get a more comprehensive view of the spatio-temporal flow behavior.
By means of a global statistical analysis of the characteristic spatial modes of the flow we extract information
about the stability of dominant large-scale modes as well as the reversal paths in state subspace. We examine
probability density functions and drift vector fields of two-dimensional state subspaces spanned by different
large-scale spatial modes. This also provides information about the coexistence of dominant modes.
 


Physical Review, DOI: 10.1103/PhysRevE.84.026309 (2011)

 


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Institut für Geophysik Geschäftsführender Direktor:
Prof. Dr. Ulrich Hansen

Corrensstraße 24
· 48149 Münster
Tel.: +49 251 83-33590 · Fax: +49 251 83-36100
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