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Taylor bubble moving in a flowing liquid in vertical channel: transition from symmetric to asymmetric shape

Figueroa-Espinoza, Bernardo and Fabre, Jean Taylor bubble moving in a flowing liquid in vertical channel: transition from symmetric to asymmetric shape. (2011) Journal of Fluid Mechanics, vol. 679 . pp. 432-454.

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Official URL: http://dx.doi.org/10.1017/jfm.2011.159

Abstract

The velocity and shape of Taylor bubbles moving in a vertical channel in a Poiseuille liquid flow were studied for the inertial regime, characterized by large Reynolds numbers. Numerical experiments were carried out for positive (upward) and negative (downward) liquid mean velocity. Previous investigations in tube have reported that for upward flow the bubble is symmetric and its velocity follows the law of Nicklin whereas for certain downward flow conditions the symmetry is broken and the bubble rises appreciably faster. To study the bubble motion and to identify the existence of a transition, a 2D numerical code that solves the Navier-Stokes equations (through a VoF implementation) was used to obtain the bubble shape and the rise velocity for different liquid mean velocity. A reference frame located at the bubble tip as well as an irregular grid were implemented to allow for long simulation times without an excessively large numerical domain. It was observed that whenever the mean liquid velocity exceeded some critical value, bubbles adopted a symmetric final shape even though their initial shape was asymmetric. Conversely, if the mean liquid velocity was smaller than that critical value, a transition to a non-symmetric shape occurred, along with a correspondingly faster velocity. It was also found that surface tension has a stabilizing effect on the transition.

Item Type:Article
Additional Information:Thanks to Cambridge University Press editor. The definitive version of this article is available at :http://dx.doi.org/10.1017/jfm.2011.159
Audience (journal):International peer-reviewed journal
Uncontrolled Keywords:
Institution:French research institutions > Centre National de la Recherche Scientifique - CNRS
Université de Toulouse > Institut National Polytechnique de Toulouse - INPT
Other partners > Universidad Nacional Autónoma de México - UNAM (MEXICO)
Université de Toulouse > Université Paul Sabatier-Toulouse III - UPS
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Deposited By: Catherine THURIOT

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