2008/02/11 by Naïs Coq, Olivia du Roure, Olivia Du Roure +4 · 2 citations
Engineering · Physics and Astronomy · #Advanced Materials and Mechanics #Micro and Nano Robotics #Modular Robots and Swarm Intelligence #cond-mat.soft #physics.flu-dyn
paper · pdf · doi:10.1063/1.2909603
arxiv created 2008/02/11 · openalex publication_date 2008/05/01 · arxiv updated 2009/12/01 · openalex created_date 2025/10/10 · openalex updated_date 2026/07/28
We experimentally analyze 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, confirming the numerical predictions of Manghi et al. [Phys. Rev. Lett. 96, 068101 (2006)]. A linearized model of the fluid-structure interaction is proposed to account for all the features of the nonlinear filament dynamics.