Dynamics of a rising bubble in a polymer solution

International audienceThe dynamics of millimeter sized air bubbles rising through a still 1\% polyacrylamide/water solution are investigated using precise ultrasound velocity measurements combined with high speed video. The oscillatory path dynamics are compared to the those of bubbles rising in water. We find distinctive changes in path geometry, the onset of path instability, as well as lift forces. Since the Deborah number for these dynamics is near unity, the observed effects are attributed to viscoelastic effects on the wake of the bubble