Abstract
Fluid-displacement experiments in Hele-Shaw cells filled with a viscoelastic fluid show a novel transition between a viscous fingering (VF) regime producing fractal patterns of ‘‘fingers’’ and a viscoelastic facturing (VEF) regime producing fractal patterns of ‘‘cracks.’’ VEF patterns are characterized by branching angles of 90° with respect to the main crack, behind the tip, and by a lower fractal dimension than VF. The transition is controlled by several parameters, including the Deborah number and the system deformability.
- Received 30 March 1990
DOI:https://doi.org/10.1103/PhysRevLett.67.2009
©1991 American Physical Society