Journal Article

PreJuSER-5079

http://join2-wiki.gsi.de/foswiki/pub/Main/Artwork/join2_logo100x88.png Dynamical regimes and hydrodynamic lift of viscous vesicles under shear

Messlinger, S.FZJ* ; Schmidt, B.FZJ* ; Noguchi, H.FZJ* ; Gompper, G.FZJ*

2009
APS College Park, Md.

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Please use a persistent id in citations: http://hdl.handle.net/2128/9327  doi:10.1103/PhysRevE.80.011901

Abstract: The dynamics of two-dimensional viscous vesicles in shear flow, with different fluid viscosities eta(in) in and eta(out) inside and outside, respectively, is studied using mesoscale simulation techniques. Besides the well-known tank-treading and tumbling motions, an oscillatory swinging motion is observed in the simulations for large shear rate. The existence of this swinging motion requires the excitation of higher-order undulation modes (beyond elliptical deformations) in two dimensions. Keller-Skalak theory is extended to deformable two-dimensional vesicles, such that a dynamical phase diagram can be predicted for the reduced shear rate and the viscosity contrast eta(in)/eta(out). The simulation results are found to be in good agreement with the theoretical predictions, when thermal fluctuations are incorporated in the theory. Moreover, the hydrodynamic lift force, acting on vesicles under shear close to a wall, is determined from simulations for various viscosity contrasts. For comparison, the lift force is calculated numerically in the absence of thermal fluctuations using the boundary-integral method for equal inside and outside viscosities. Both methods show that the dependence of the lift force on the distance y(cm) of the vesicle center of mass from the wall is well described by an effective power law y(cm)(-2) for intermediate distances 0.8R(p) less than or similar to y(cm) less than or similar to 3R(p) with vesicle radius R-p. The boundary-integral calculation indicates that the lift force decays asymptotically as 1/[y(cm) 1n(y(cm))] far from the wall.

Keyword(s): J

Note: Record converted from VDB: 12.11.2012

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Contributing Institute(s):

1. Theorie der Weichen Materie und Biophysik (IFF-2)
2. Theorie der Weichen Materie und Biophysik (IAS-2)
3. Jülich Aachen Research Alliance - High-Performance Computing (JARA-HPC)

Research Program(s):

1. Kondensierte Materie (P54)

Appears in the scientific report 2009

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Database coverage:
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