Viscous fingering patterns in polymer solutions

✍ Scribed by Masami Kawaguchi; Kyoko Makino; Tadaya Kato

• Publisher: Elsevier Science
• Year: 1997
• Tongue: English
• Weight: 650 KB
• Volume: 109
• Category: Article
• ISSN: 0167-2789
• DOI: 10.1016/s0167-2789(97)00069-9

✦ Synopsis

Characteristics of viscous fingering patterns in polymer solutions were investigated by radially pushing air in a radial Hele-Shaw cell containing hydroxypropyl methyl cellulose (HPMC) solutions. Low and high molecular weight HPMC samples were used. An increase in molecular weight easily yielded chain entanglements, which led to a strong shear thinning and an increase in elasticity. For the low molecular weight HPMC solutions, only the dense-branching patterns were observed over the entire injection pressure range. On the other hand, for the high molecular weight HPMC solutions, the resulting patterns showed a systematic change from dense-branching to skewering patterns through splitting patterns as the injection pressure increased. The characteristic quantities of pattern growth, such as the finger width and tip velocity, were evaluated. Darcy's law was compared with the measured tip velocity. HPMC solutions provided a linear relation between the measured tip velocity and the ratio of the injection pressure to effective viscosity at a shear rate imposed to HPMC solutions.