Berlin 2008 – scientific programme

Parts | Days | Selection | Search | Downloads | Help

CPP: Fachverband Chemische Physik und Polymerphysik

CPP 27: Micro and Nano Fluidics II: Slipping + soft objects in flow

CPP 27.4: Talk

Thursday, February 28, 2008, 14:45–15:00, C 264

Flows driven by wettability gradients: A lattice Boltzmann study — •Fathollah Varnik and Dierk Raabe — Max-Planck Institut für Eisenforschung, Düsseldorf, Germany

Guided motion of liquids is studied via lattice Boltzmann computer simulations. The focus of the work is on basic issues related to driving forces generated via a step-wise (abrupt) change in wetting properties of the substrate along a given spatial direction. We first give approximate analytic expressions for forces driving the liquid motion. These theoretical estimates show qualitatively different dependence of wetting gradient induced forces on contact angle and liquid volume in the case of an open substrate as opposed to a planar channel. These results are then examined via lattice Boltzmann computer simulations. Furthermore, we also investigate effects of a wetting gradient on internal droplet dynamics and the resulting dissipation losses.