Journal of Fluid Mechanics Webinar Series: François Gallaire, EPFL, Switzerland

The Leeds Institute for Fluid Dynamics is delighted to partner with the Department of Applied Mathematics and Theoretical Physics at the University of Cambridge, the UK Fluids Network, and the Journal of Fluid Mechanics to deliver a regular webinar series on fluids-related topics.

The autumn edition of the Fluid Mechanics Webinar Series will take place over ten weeks between 2nd October and 4th December 2020. Registration will remain open, and please note that if you have already registered you need not register again.

Video recordings of past webinars will be made available soon. Watch this space!

Speaker: François Gallaire, EPFL, Switzerland

Date/Time: Friday 9th October, 2020. 4:00 pm BST/11 am EDT

Title: Dripping down the rivulet

Abstract: We revisit the canonical Rayleigh-Taylor instability and investigate the case of a thin film of liquid continuously flowing down the underside of an inclined plane. The presence of a natural flow along the plane competes with the conventional droplet forming instability and gives rise to an intricate pattern formation, which is studied experimentally, numerically and theoretically using the lubrication equation. We observe the prevalence of streamwise-invariant structures, modulated along the transverse direction perpendicular to the flow direction, called rivulets. We determine the universal thickness profile towards which they saturate and explore the origin of this pattern selection by analyzing the impulse response as well as the response to localized defect on the substrate. We eventually discuss the role of these hydrodynamic instabilities on the morphogenesis of some typical karst draperies structures encountered in limestone caves.