OATAO - Open Archive Toulouse Archive Ouverte Open Access Week

Numerical simulation of bubble dispersion in turbulent Taylor-Couette flow

Chouippe, Agathe and Climent, Éric and Legendre, Dominique and Gabillet, Céline Numerical simulation of bubble dispersion in turbulent Taylor-Couette flow. (2014) Physics of Fluids, 26 (4). 043304. ISSN 1070-6631

[img]
Preview
(Document in English)

PDF (Author's version) - Requires a PDF viewer such as GSview, Xpdf or Adobe Acrobat Reader
3MB

Official URL: http://dx.doi.org/10.1063/1.4871728

Abstract

We investigate bubble dispersion in turbulent Taylor-Couette flow. The aim of this study is to describe the main mechanisms yielding preferential bubble accumulation in near-wall structures of the flow. We first proceed to direct numerical simulation of Taylor-Couette flows for three different geometrical configurations (three radius ratios η = R 1/R 2: η = 0.5, η = 0.72, and η = 0.91 with the outer cylinder at rest) and Reynolds numbers corresponding to turbulent regime ranging from 3000 to 8000. The statistics of the flow are discussed using two different averaging procedures that permit to characterize the mean azimuthal velocity, the Taylor vortices contribution and the small-scale turbulent fluctuations. The simulations are compared and validated with experimental and numerical data from literature. The second part of this study is devoted to bubble dispersion. Bubble accumulation is analyzed by comparing the dispersion obtained with the full turbulent flow field to bubble dispersion occurring at lower Reynolds numbers in previous works. Several patterns of preferential accumulation of bubbles have been observed depending on bubble size and the effect of gravity. For the smaller size considered, bubbles disperse homogeneously throughout the gap, while for the larger size they accumulate along the inner wall for the large gap width (η = 0.5). Varying the intensity of buoyancy yields complex evolution of the bubble spatial distribution. For low gravity effect, bubble entrapment is strong leading to accumulation along the inner wall in outflow regions (streaks of low wall shear stress). When buoyancy effect dominates on vortex trapping, bubbles rise through the vortices, while spiral patterns stretched along the inner cylinder are clearly identified. Force balance is analyzed to identify dominating forces leading to this accumulation and accumulation patterns are compared with previous experiments.

Item Type:Article
Additional Information:Thanks to AIP Publishing. The definitive version is available at http://scitation.aip.org The original PDF of the article can be found at Physics of Fluids website : http://scitation.aip.org/content/aip/journal/pof2/26/4/10.1063/1.4871728
Audience (journal):International peer-reviewed journal
Uncontrolled Keywords:
Institution:Other partners > Arts et Métiers ParisTech (FRANCE)
French research institutions > Centre National de la Recherche Scientifique - CNRS (FRANCE)
Other partners > Ecole Navale (FRANCE)
Université de Toulouse > Institut National Polytechnique de Toulouse - INPT (FRANCE)
Université de Toulouse > Université Toulouse III - Paul Sabatier - UPS (FRANCE)
Laboratory name:
Statistics:download
Deposited By: Eric CLIMENT
Deposited On:15 Apr 2016 10:02

Repository Staff Only: item control page