Interfacial phenomena At the CNLD, we study two interfacial phenomena: viscous fingering and the bouncing jet.  Viscous fingering occurs when a less viscous fluid is driven into a more viscous fluid.  The interface between the two fluids doesn't not grow uniformly; rather, the interface grows the fastest where it penetrates the more viscous fluid the most.  Accordingly, the interface grows the slowest where it penetrates the more viscous fluid the least.  Complicated fingering patterns grow out of this instability.  This instability is important in petroleum extraction, coating, injection molding, and many other industrial processes. The bouncing jet is an intriguing phenomena where a liquid stream poured into a horizontally moving bath does not smoothly merge with the bulk fluid.  Instead the liquid jet bounces off the surface of the bath by rebounding off an indentation the jet makes in the bath's surface.

Projects Viscous Fingering The Bouncing Jet