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Oscillations of the large-scale circulation in turbulent mixed convection in a closed rectangular cavity

Schmeling, Daniel and Bosbach, Johannes and Wagner, Claus (2013) Oscillations of the large-scale circulation in turbulent mixed convection in a closed rectangular cavity. Experiments in Fluids, Vol. 5 (5), pp. 1-15. Springer. DOI: 10.1007/s00348-013-1517-3 ISSN 0723-4864

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Official URL: http://link.springer.com/article/10.1007/s00348-013-1517-3

Abstract

Fluid temperature time series are recorded in turbulent mixed convection at specific locations inside a cuboidal convection cell. They reveal instabilities of the large-scale flow structures, which organise the heat transport in an intermediate range of Archimedes numbers, where buoyancy and inertia forces are of similar strength. The instabilities lead to periodic or spontaneous transitions between three and four convection rolls. Further, for either high Rayleigh or Reynolds numbers, for which the flow is either governed by buoyancy or by inertia forces, respectively, stable large-scale circulations (LSCs) develop. In the intermediate Ra–Re number regime, we ascribe the complex dynamics, visible as oscillation in the temperature time series, to the interaction of the pressure-driven wall jet at the ceiling with the buoyancy-driven LSCs. The maximal main oscillation frequency is about one order of magnitude smaller than the turnover frequencies of either the wall jet-induced circulation rolls or thermally induced LSCs. It is further shown that the periodic reconfigurations of the LSCs can be controlled by adjusting the inflow velocity, that is, the Reynolds number, to generate stable LSCs.

Item URL in elib:https://elib.dlr.de/76707/
Document Type:Article
Additional Information:Online ISSN: 1432-1114, Article:1517
Title:Oscillations of the large-scale circulation in turbulent mixed convection in a closed rectangular cavity
Authors:
AuthorsInstitution or Email of AuthorsAuthors ORCID iD
Schmeling, Danieldaniel.schmeling (at) dlr.deUNSPECIFIED
Bosbach, Johannesjohannes.bosbach (at) dlr.deUNSPECIFIED
Wagner, Clausclaus.wagner (at) dlr.deUNSPECIFIED
Date:2013
Journal or Publication Title:Experiments in Fluids
Refereed publication:Yes
Open Access:No
Gold Open Access:No
In SCOPUS:Yes
In ISI Web of Science:Yes
Volume:Vol. 5
DOI :10.1007/s00348-013-1517-3
Page Range:pp. 1-15
Publisher:Springer
ISSN:0723-4864
Status:Published
Keywords:mixed convection, cuboidal cavity, oscillations, reconfigurations, large-scale circulation
HGF - Research field:Aeronautics, Space and Transport
HGF - Program:Transport
HGF - Program Themes:Terrestrial Vehicles (old)
DLR - Research area:Transport
DLR - Program:V BF - Bodengebundene Fahrzeuge
DLR - Research theme (Project):V - Projekt Next Generation Train (old)
Location: Göttingen
Institutes and Institutions:Institute of Aerodynamics and Flow Technology > Fluid Systems
Deposited By: Schmeling, Dr Daniel
Deposited On:15 May 2013 16:08
Last Modified:06 Sep 2019 15:25

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