Stick-slip instability for viscous fingering in a gel
Soft Condensed Matter
2009-11-07 v1
Abstract
The growth dynamics of an air finger injected in a visco-elastic gel (a PVA/borax aqueous solution) is studied in a linear Hele-Shaw cell. Besides the standard Saffmann-Taylor instability, we observe - with increasing finger velocities - the existence of two new regimes: (a) a stick-slip regime for which the finger tip velocity oscillates between 2 different values, producing local pinching of the finger at regular intervals, (b) a ``tadpole'' regime where a fracture-type propagation is observed. A scaling argument is proposed to interpret the dependence of the stick-slip frequency with the measured rheological properties of the gel.
Cite
@article{arxiv.cond-mat/0201136,
title = {Stick-slip instability for viscous fingering in a gel},
author = {N. Puff and G. Debregeas and J. -M. di Meglio and D. Higgins and C. Wagner and D. Bonn},
journal= {arXiv preprint arXiv:cond-mat/0201136},
year = {2009}
}
Comments
7 pages, 4 figures. Submitted to Europhysics Letters