Negative wake and velocity of a bubble rising in a viscoelastic fluid

Shriram B. Pillapakkam, Pushpendra Singh

Research output: Contribution to journalArticle

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Abstract

A three-dimensional finite element based numerical method is used to simulate the rise of a bubble in a viscoelastic fluid modeled by the Oldroyd-B model. The rise velocity is studied as a function of the bubble volume on a log-log plot. The dependence of rise velocity on the bubble shape and the viscoelastic properties of the ambient fluid are also investigated. In simulations, rather than a jump in the rise velocity at a critical volume as observed in experiments, we find that there is a steep, but continuous, change in the rise velocity over a very small range of bubble volumes. Interestingly, this steep increase in the rise velocity is exaggerated when a parameter, which is a measure of the polymer concentration, is increased, while keeping the zero-shear viscosity fixed. The wake is 'negative' in the sense that the direction of fluid velocity behind the bubble for this parameter range is the opposite of that for a Newtonian fluid.

Original languageEnglish (US)
Pages (from-to)709-714
Number of pages6
JournalAmerican Society of Mechanical Engineers, Fluids Engineering Division (Publication) FED
Volume259
DOIs
StatePublished - Jan 1 2003

All Science Journal Classification (ASJC) codes

  • Engineering(all)

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