(184i) Rapidly Moving Contact-Lines and Inviscid Flows

Contact-lines that are driven far from equilibrium are found in a range of industrially important processes, including coating operations and immersion lithography for integrated chip fabrication.  We study the way a liquid moves along a solid, advancing or receding against a gas under conditions where surface tension of the free interface and inertia of the underlying flow are in balance.  The moving contact-line is defined as the common line between the free interface and the driving solid substrate.  When the liquid flow adjacent to the interface is predominantly inviscid, the contact-line motion can be rapid.  We report solutions to the inviscid equations of motion and interfacial boundary conditions that deliver meniscus dynamics and rapid contact-line motion.  A perturbation analysis shows how the inviscid flow influences the meniscus dynamics and thereby the contact-line motion which can exhibit various stick-slip behaviors.  Rapid contact-line motion (meters per second) can be captured and examined in experiments where the flow solidifies, as with quenched liquid metals frozen by the planar-flow process.  We compare our predictions against experiment using the frozen-in flow patterns as a signature of contact-line motion.