Regensburg 2007 – scientific programme

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CPP: Fachverband Chemische Physik und Polymerphysik

CPP 24: Micro and Nano Fluidics II: Soft Objects in Flow + Slippage

CPP 24.1: Invited Talk

Thursday, March 29, 2007, 09:30–10:00, H37

Fluctuating 2d vesicles in hydrodynamic Stokes flow — •Reimar Finken and Udo Seifert — II. Institut für Theoretische Physik, Pfaffenwaldring 57, 70550 Stuttgart, Germany

The behaviour of soft objects in hydrodynamic flow has received increasing attention in recent years, both theoretically and experimentally. An important and intriguing aspect is the interaction of the flow with thermal fluctuations in this non-equilibrium situation. As a paradigmatic model system we study the stochastic motion of a vesicle with a one dimensional membrane in a planar shear flow. At large shear rate the hydrodynamic forces stretch out the membrane fluctuations. The simplified geometry allows easier analytic treatment and makes the system amenable to computer simulations. We develop a theory which takes advantage of small deviations from a circular shape and obtain Langevin type equations of motion for the deformation amplitudes. Analytic expressions are obtained for the stationary state and for the correlation functions of the deformation. Our analytic results are compared with simulation data. This work was funded by the DFG Priority Program SPP 1164 “Nano- and Microfluidics”.