DPG Phi
Verhandlungen
Verhandlungen
DPG

Dresden 2006 – scientific programme

Parts | Days | Selection | Search | Downloads | Help

CPP: Chemische Physik und Polymerphysik

CPP 24: POSTER Microfluidics

CPP 24.2: Poster

Thursday, March 30, 2006, 17:00–19:00, P2

Free-Surface shapes of strongly deformed driven micro-droplets — •Michael Schindler1, Peter Talkner1, Peter Hänggi1, and Uwe Thiele21Institut für Physik, Universität Augsburg — 2MPI Physik Komplexer Systeme, Dresden

We propose a Finite-Element algorithm to compute free surface shapes that are significantly deformed by an applied static (gravitation) or dynamic (surface-accoustic waves) driving. In the micro-fluidic regime, where the surface tension forces become important the central difficulty resides in the approximation of the discretized curvature. We present a method how the discretization of the free surface can automatically be kept regular using a smooth transition to the behaviour of a rubber band.

By employing a variational approach we can show that the surface position must be discretized with the same order of accuracy as the velocity components. Otherwise, the free-surface boundary problem will be inconsistently formulated and give rise to approximation errors, as numerical observations confirm.

As examples we show pending pinned droplets on a flat substrate under the sole influence of gravity and capillarity and also droplets driven by surface-acoustic waves. In the limit of droplets with small equilibrium contact angles the results of our Finite-Element technique are compared to results of a lubrication approximation model.

100% | Mobile Layout | Deutsche Version | Contact/Imprint/Privacy
DPG-Physik > DPG-Verhandlungen > 2006 > Dresden