Flow around individual Taylor bubbles rising in stagnant CMC solutions: PIV measurements

• Type: Article in International Scientific Journal
• Date: 2005

Authors

R. G. Sousa (Author) Other; M. L. Riethmuller (Author) Other; A. M. F. R. Pinto (Author) FEUP; J. B. L. M. Campos (Author) FEUP

Journal

Title: Chemical Engineering Science

Vol. 60 No. 2

Pages: 1859-1873

ISSN: 0009-2509

Publisher: Elsevier

Indexing

ISI Web of Knowledge - 41 Citations

ISI Web of Science

Scopus - 41 Citations

INSPEC

COMPENDEX

Scientific classification

CORDIS: Technological sciences

Other information

Authenticus ID: P-000-3YD

DOI: 10.1016/j.ces.2004.11.035

Abstract (EN): The flow around single Taylor bubbles rising in non-Newtonian solutions of Carboxymethylcellulose (CMC) polymer was studied using simultaneously particle image velocimetry (PIV) and shadowgraphy. This technique made it possible to determine the correct position of the bubble interface. Solutions of polymer with weight percentage varying from 0.1 to 1.0 wt% were used to cover a wide range of flow regimes. The theological fluid properties and pipe dimension yielded Reynolds numbers between 4 and 714 and Deborah numbers for the higher concentration solutions between 0.001 and 0.236. The shape of the bubbles rising in the different solutions was compared. The flow around the nose of the bubbles was found to be similar in all the studied conditions. Velocity profiles in the liquid film around the bubble were measured and different wake structures were found. With increasing solution viscosity, the wake flow pattern varied from turbulent to laminar, and a negative wake was observed for the higher polymer concentration solutions.

Language: English

Type (Professor's evaluation): Scientific

No. of pages: 15