| Wed June 18th 2014 16:00 – 17:00 ZH286 | Seminar | Self-similar Scalings in Focusing Flows Driven by Capillary and Gravitational Forces Joshua Dijksman |
Details:A thin layer of fluid on a solid substrate displays surprisingly rich dynamics, due to the interplay of surface tension, gravitational and viscous forces at many length scales. One beautiful example of this richness is in the universe of "focusing flows": flows that emerge in the slow wetting of a dry patch, by a surrounding thin liquid film. The flow behavior during this focusing is self-similar. The scaling behavior has non-trivial exponents, as was shown by now classic work by Diez c.s. in the early nineties, and the various forces mentioned all have nontrivial influence on this behavior.We study these converging fluid films driven by both surface tension (gradients) and gravitational forcing, in isothermal and non-isothermal settings. Our numerical and experimental study explores, among others, the complete range of flow regimes from surface tension driven to gravity induced wetting. The intermediate regime spans a surprisingly large range of Bond numbers, and limits all realistic focusing flows to the intermediate scaling regime. We verify the validity of numerical methodology and results with various experiments. We also explore basic surface tension gradient driven wetting behavior. | ||
