Large-scale mean patterns in turbulent convection
نویسندگان
چکیده
منابع مشابه
Heat transfer & large-scale dynamics in turbulent Rayleigh-Bénard convection
The progress in our understanding of several aspects of turbulent Rayleigh-Bénard convection is reviewed. The focus is on the question of how the Nusselt number and the Reynolds number depend on the Rayleigh number Ra and the Prandtl number Pr, and on how the thicknesses of the thermal and the kinetic boundary layers scale with Ra and Pr. Non-Oberbeck-Boussinesq effects and the dynamics of the ...
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In turbulent Rayleigh-Bénard convection, a large-scale circulation (LSC) develops in a nearly vertical plane and is maintained by rising and falling plumes detaching from the unstable thermal boundary layers. Rare but large fluctuations in the LSC amplitude can lead to extinction of the LSC (a cessation event), followed by the reemergence of another LSC with a different (random) azimuthal orien...
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We report on the dynamics and structure of the turbulent velocity field in a high-Rayleigh-number (Ra = 5.9 x 10(8))thermal convection cell with an aspect ratio of 4. Spectral density functions (measured with laser Doppler velocimetry) indicated the existence of a large-scale periodic component. The long-time mean flow field (measured with particle image velocimetry) revealed that the large-sca...
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In the last decades it has been recognized that the very high Rayleigh number convective boundary layer (CBL) has more complex nature than might be reckoned. Besides the fully organized component naturally considered as the mean flow and the chaotic small-scale turbulent fluctuations, one more type of motion has been discovered, namely, long-lived large-scale structures, which are neither turbu...
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ژورنال
عنوان ژورنال: Journal of Fluid Mechanics
سال: 2015
ISSN: 0022-1120,1469-7645
DOI: 10.1017/jfm.2015.316