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Rayleigh-Bénard convection in liquids with temperature-dependent material properties

Horn, Susanne and Shishkina, Olga and Wagner, Claus (2012) Rayleigh-Bénard convection in liquids with temperature-dependent material properties. XXIII ICTAM, 19. -24. Aug. 2012, Beijing, China. ISBN 978-988-16022-3-7.

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The influence of non-Oberbeck-Boussinesq (NOB) effects on Rayleigh-Bénard convection in liquids is investigated by means of three-dimensional direct numerical simulations (DNS). For this purpose the impact of temperature dependent material properties is studied in water with a Prandtl number of Pr = 4.38 within a range of Rayleigh numbers of 10^7 ≤ Ra ≤ 10^9 and in glycerol with Pr = 2547.9 and within 10^5 ≤ Ra ≤ 10^9. The imposed temperature differences ∆ reach up to 70K in the case of water and up to 80K in the case of glycerol. The generated flow fields are analysed with respect to deviations from the Oberbeck-Boussinesq (OB) case. We obtain a breakdown of the top-bottom symmetry, that is, different boundary layer thicknesses, modified mean temperature profiles, entailing an increase of the centre temperature, and asymmetric velocity flow patterns. Furthermore the influence on the scaling behaviour of the Reynolds number Re and the Nusselt number Nu is studied.

Document Type:Conference or Workshop Item (Speech, Paper)
Title:Rayleigh-Bénard convection in liquids with temperature-dependent material properties
AuthorsInstitution or Email of Authors
Horn, Susannesusanne.horn@dlr.de
Shishkina, Olgaolga.shishkina@dlr.de
Wagner, Clausclaus.wagner@dlr.de
Date:August 2012
Refereed publication:No
In ISI Web of Science:No
Volume:Book o
Series Name:Conference Proceedings on DVD-ROM 1.4G
Keywords:Rayleigh-Bénard convection, NOB effects
Event Location:Beijing, China
Event Type:international Conference
Event Dates:19. -24. Aug. 2012
HGF - Research field:Aeronautics, Space and Transport
HGF - Program:Transport
HGF - Program Themes:Terrestrial Vehicles
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: Susanne Horn
Deposited On:14 Nov 2012 11:51
Last Modified:12 Dec 2013 21:50

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