English

Rotational dynamics of a soft filament: wrapping transition and propulsive forces

Fluid Dynamics 2009-11-13 v1 Soft Condensed Matter

Abstract

We analyze experimentally the shape of a long elastic filament rotating in a viscous liquid. We identify a continuous but sharp transition from a straight to an helical shape, resulting from the competition between viscous stresses and elastic forces. This induced helicity generates a propulsive force along the axis of rotation. In addition, we show that the shape transition is associated with an unstable branch in the force-torque relation. A linearized model of the fluid-structure interaction is proposed to account for all the features of the non-linear filament dynamics.

Keywords

Cite

@article{arxiv.0802.1503,
  title  = {Rotational dynamics of a soft filament: wrapping transition and propulsive forces},
  author = {Naïs Coq and Olivia Du Roure and Joel Marthelot and Denis Bartolo and Marc Fermigier},
  journal= {arXiv preprint arXiv:0802.1503},
  year   = {2009}
}
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