Two-dimensional fluctuating vesicles in linear shear flow.
The stochastic motion of a two-dimensional vesicle in linear shear flow is studied at finite temperature. In the limit of small deformations from a circle, Langevin-type equations of motion are derived, which are highly nonlinear due to the constraint of constant perimeter length. These equations are solved in the low-temperature limit and using a mean-field approach, in which the length constraint is satisfied only on average. The constraint imposes non-trivial correlations between the lowest deformation modes at low temperature. We also simulate a vesicle in a hydrodynamic solvent by using the multi-particle collision dynamics technique, both in the quasi-circular regime and for larger deformations, and compare the stationary deformation correlation functions and the time autocorrelation functions with theoretical predictions. Good agreement between theory and simulations is obtained.
Finken
R
R
II. Institut für Theoretische Physik, Universität Stuttgart, 70550 Stuttgart, Germany. finken@theo2.physik.uni-stuttgart.de
Lamura
A
A
Seifert
U
U
Gompper
G
G