title: Viscous to inertial crossover in liquid drop coalescence.
abstract: Using an electrical method and high-speed imaging, we probe drop coalescence down to 10 ns after the drops touch. By varying the liquid viscosity over two decades, we conclude that, at a sufficiently low approach velocity where deformation is not present, the drops coalesce with an unexpectedly late crossover time between a regime dominated by viscous and one dominated by inertial effects. We argue that the late crossover, not accounted for in the theory, can be explained by an appropriate choice of length scales present in the flow geometry.
authors.affiliation: The James Franck Institute and Department of Physics, The University of Chicago, Chicago, Illinois 60637, USA. paulsenj@uchicago.edu
authors.forename: Joseph D
authors.initials: JD
authors.lastname: Paulsen
authors.forename: Justin C
authors.initials: JC
authors.lastname: Burton
authors.forename: Sidney R
authors.initials: SR
authors.lastname: Nagel