Berlin 2015 – wissenschaftliches Programm

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CPP: Fachverband Chemische Physik und Polymerphysik

CPP 46: P11: Wetting, Micro and Nano Fluidics

CPP 46.20: Poster

Mittwoch, 18. März 2015, 10:00–13:00, Poster A

Inertial migration of elastic capsules in Poiseuille flow — •Kevin Irmer, Christopher Prohm, and Holger Stark — Institute of Theoretical Physics, Technische Universität Berlin, Hardenbergstr. 36, 10623 Berlin, Germany

The influence of inertia on the rheology of deformable particles such as capsules, vesicles and red blood cells in flow has attracted much interest over the last few years. Many applications in biology and medical sciences rely on inertial effects. Especially the separation of particles like cancer cells from red blood cells plays an important role.

Using Lattice-Boltzmann simulations, we study the dynamics of a single deformable capsule in microfluidic channels with rectangular cross sections for intermediate Reynolds numbers.

In the channel cross section the capsules migrate towards stable equilibrium positions. We find that the locations of these positions shift towards the channel center for increasing deformability of the capsule and decreasing inertia of the flow. In particular, they strongly depend on deformability quantified by the capillary number. Hence we present a new possibility to separate capsules and other deformable particles by size and deformability. For Reynolds numbers below 100, the equilibrium positions collapse onto a single master curve depending only on the Laplace number.

Finally we determine lift force profiles for channel cross sections with different aspect ratios. The profiles determine inertial migration in the cross section.