Lecturer: Roiy Sayag, Ben-Gurion University of the Negev
Abstract:
The interface of a fluid that displaces another fluid in a quasi-two
dimensional geometry can develop fingering patterns, which are common
to a wide range of systems. It is believed that such interfaces
remain stable, having planer or circular shapes, when the displacing
fluid is more viscous (less mobile). However, some systems, such as
ice sheets or squeezed pastes, demonstrate fingering patterns in spite
of having a more viscous displacing fluid. I will show that fingering
patterns can emerge when the displacing fluid is more viscous if
friction along the flow boundaries is sufficiently weak. Unlike the
classical viscous fingering, the characteristic wavelength in the
patterns we observe progressively grows.