TY  - JOUR
AU  - Saggiorato, Guglielmo
AU  - Elgeti, Jens
AU  - Winkler, Roland G.
AU  - Gompper, Gerhard
TI  - Confirmations, hydrodynamic interactions, and instabilities of sedimenting semiflexible filaments
JO  - Soft matter
VL  - 11
IS  - 37
SN  - 1744-6848
CY  - London
PB  - Royal Soc. of Chemistry
M1  - FZJ-2015-06195
SP  - 7337 - 7344
PY  - 2015
AB  - The conformations and dynamics of semiflexible filaments subject to a homogeneous external (gravitational) field, e.g., in a centrifuge, are studied numerically and analytically. The competition between hydrodynamic drag and bending elasticity generates new shapes and dynamical features. We show that the shape of a semiflexible filament undergoes instabilities as the external field increases. We identify two transitions that correspond to the excitation of higher bending modes. In particular, for strong fields the filament stabilizes in a non-planar shape, resulting in a sideways drift or in helical trajectories. For two interacting filaments, we find the same transitions, with the important consequence that the new non-planar shapes have an effective hydrodynamic repulsion, in contrast to the planar shapes which attract themselves even when their osculating planes are rotated with respect to each other. For the case of planar filaments, we show analytically and numerically that the relative velocity is not necessarily due to a different drag of the individual filaments, but to the hydrodynamic interactions induced by their shape asymmetry.
LB  - PUB:(DE-HGF)16
UR  - <Go to ISI:>//WOS:000361550000014
C6  - pmid:26270609
DO  - DOI:10.1039/C5SM01069A
UR  - https://juser.fz-juelich.de/record/256219
ER  -