Dresden 2017 – wissenschaftliches Programm
CPP 28.5: Vortrag
Dienstag, 21. März 2017, 15:15–15:30, ZEU 160
Migration-transition of sedimenting soft particles in vertical flows — •Andre Förtsch, Matthias Laumann, Diego Kienle, and Walter Zimmermann — Theoretische Physik I, Universität Bayreuth
The dynamics of soft, heavy (light) particles is investigated in plane Poiseuille flows between two vertical walls and in the limit of a vanishing Reynolds number. We observe, that heavy (light) soft particles migrate to (away from) the center of a parabolic Poiseuille flow profile with the flow direction parallel to the gravitational force, similar as for buoyant particles. If the flow direction is reversed and antiparallel to gravitation, we find a surprising reversal of the migration direction and heavier (lighter) particles migrate away from (to) the center of a parabolic flow profile. This transition of the migration direction is determined numerically by the Stokesian particle dynamics and the Lattice-Boltzmann-Method as well as analytically in case of small deformations of a ring polymer. The migration away from the center is slowed down due to hydrodynamic particle-wall interactions. The parameter dependence of the final off center particle position may be used for separating different particles.