Long Bubble Penetration through Viscoelastic Fluids in a Suddenly Contracting and Expanding Tube

Autor: Ching-Chuan Chang, Huang-Chih Lin, Ming-Yuan Lin, Te-Hui Tsai
Jazyk: angličtina
Rok vydání: 2016
Předmět:
Zdroj: Advances in Materials Science and Engineering, Vol 2016 (2016)
Druh dokumentu: article
ISSN: 1687-8434
1687-8442
DOI: 10.1155/2016/6702679
Popis: This study investigated the properties of long bubbles penetrating viscoelastic fluids in a suddenly contracting and expanding tube. Injection gas flow is controlled by a mass flow controller (MFC). Some of dimensionless parameters, such as the capillary number (Ca), the Reynolds number (Re), the fractional ratio (m), and the Weissenberg number (Wi), are discussed herein. The experimental results showed that bubble velocity, Ca, and Wi increase as shear viscosity increases under a constant gas flow by MFC. However, as shear viscosity increases, bubble diameter decreases, and m increases. When gas flow is 200 mL/min and shear viscosity increases, the bubble front is sharper in the contraction tube, and the bubble front shape is blunter in the sudden expansion tube. When gas flow is 600 mL/min and shear viscosity increases, the bubble front is blunter in the contraction tube and exhibits a torch shape in the sudden expansion tube.
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