title: Relevance of dynamic wetting in viscous fingering patterns.
abstract: We demonstrate that wetting effects at moving contact lines have a strong impact in viscous fingering patterns. Experiments in a rotating Hele-Shaw (HS) cell, dry or prewetted, show consistent morphological differences. When the wetting fluid invades a dry region, contact angle dynamics yield a kinetic contribution to the interface pressure drop that scales with capillary number as Ca(2/3) but is significantly larger than the Park-Homsy kinetic correction. Numerical results are in very good agreement with experiments and show that standard HS equations work best for prewetted cells.
authors.affiliation: Department of Physics of Complex Systems, Weizmann Institute of Science, Rehovot 76100, Israel.
authors.forename: E
authors.initials: E
authors.lastname: Alvarez-Lacalle
authors.forename: J
authors.initials: J
authors.lastname: Ortín
authors.forename: J
authors.initials: J
authors.lastname: Casademunt