Regensburg 2007 – scientific programme

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BP: Fachverband Biologische Physik

BP 11: Micro- and Nanofluidics

BP 11.2: Talk

Tuesday, March 27, 2007, 16:15–16:30, H43

Self-propulsive motions of elastic filaments — •Hirofumi Wada and Roland Netz — Physics Department, TUM, Garching, Germany

Microbiology provides rich examples of self-propulsive motions in a viscous fluid, where inertia plays no role and the concept of momentum conservation does not work. In such a inertia-less limit, the Navier-Stokes equation is linearized, leading to the conclusion that geometrically reversible motion does not render any net thrust. Using hydrodynamic simulations, we study propulsive behavior of a few types of model-Stokesian swimmers with slender filaments, such as a rotating elastic rod and bistable helices. The generation of a shape change through an elastic instability or an active excitation results in a substantial forward thrust. The hydrodynamic efficiency, as well as its optimum condition, is examined in presence of thermal fluctuations. Its biological connection is also discussed.