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

• Type: Article in International Conference Proceedings Book
• Date: 2004

Authors

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

Conference proceedings International

Title: 3 th International Symposium on Two-Phase Flow Modelling and Experimentation

3 th International Symposium on Two-Phase Flow Modelling and Experimentation

Pisa, September 2004

Indexing

Scopus

Scientific classification

FOS: Engineering and technology > Chemical engineering

CORDIS: Technological sciences > Engineering > Chemical engineering

Other information

Abstract (EN): The flow around single Taylor bubbles rising in non-Newtonian solutions of Carboxymethylcellulose (CMC) polymer was studied using a simultaneous technique employing particle image velocimetry (PIV) and shadowgraphy. This technique solved previous problems on finding the correct position of the bubble interface. Solutions of different polymer weight percentage, varying from 0.1 to 1.0 wt% were used to cover a wide range of flow regimes. The rheological fluid properties and pipe dimension yielded Reynolds numbers between 4 and 254 and Deborah numbers between 0.012 and 0.402. The shape of the bubbles in the different fluids 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. Different wake structures were found in the different solutions studied. With increasing viscosity, the wake flow varied from turbulent to laminar, being possible to observe a negative wake for the higher polymer concentration solutions. A comparison between the different wake structures was made.

Language: English

Type (Professor's evaluation): Scientific

No. of pages: 8