Effect of aspectratio on vortex distribution and heat transfer in rotating Rayleigh-Bénard convection

J.V. Overkamp, R.J.A.M. Stevens, D. Lohse, H.J.H. Clercx

Research output: Chapter in Book/Report/Conference proceedingConference contributionAcademicpeer-review

Abstract

Numerical and experimental data for the heat transfer as function of the Rossby number Ro in rotating Rayleigh-Benard are presented for Pr = 4.38 and up to Ra = 4.52 × 109 . The aspect ratio is varied between G = 0.5 and G = 2.0. Without rotation, where the aspect ratio influences the global flow structure, we see a small aspect-ratio dependence in the Nusselt number. For stronger rotation, i.e. 1/Ro 1/Roc, the heat transport becomes independent of the aspect-ratio. We interpret this finding as follows: In the rotating regime the heat is mainly transported by vertically-aligned vortices. Since these vortices are local, the aspect ratio has a negligible effect on the heat transport in the rotating regime. Indeed, an analysis of the vortex statistics shows that the fraction of the horizontal area that is covered by vortices is aspect-ratio independent when 1/Ro 1/Roc. In agreement with the results of Weiss & Ahlers (2011) we find a vortex-depleted area close to the sidewall. Here, we show that there is also an area with enhanced vortex concentration next to the vortex-depleted edge region and that the absolute widths of both regions are independent of the aspect ratio.
Original languageEnglish
Title of host publicationProceedings of the European Turbulence Conference (ETC 13), September 12-15, 2011, Warsaw, Poland
EditorsK. Bajer
Pages082009-1/9
DOIs
Publication statusPublished - 2011
Eventconference; 13th EUROMECH European Turbulence Conference -
Duration: 1 Jan 2011 → …

Publication series

NameJournal of Physics: Conference Series
Volume318
ISSN (Print)1742-6588

Conference

Conferenceconference; 13th EUROMECH European Turbulence Conference
Period1/01/11 → …
Other13th EUROMECH European Turbulence Conference

Fingerprint Dive into the research topics of 'Effect of aspectratio on vortex distribution and heat transfer in rotating Rayleigh-Bénard convection'. Together they form a unique fingerprint.

Cite this