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arXiv · 0802.1503

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

Naïs Coq·Olivia Du Roure·Joel Marthelot·Denis Bartolo·Marc Fermigier
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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.

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physics.flu-dyncond-mat.soft

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Naïs Coq, Olivia Du Roure, Joel Marthelot, Denis Bartolo, Marc Fermigier. 2008-02-11. Rotational dynamics of a soft filament: wrapping transition and propulsive forces. https://doi.org/10.1063/1.2909603

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