April 6, Wednesday 13:45-14:45
“What would a body need to swim?“
Fluid-body coupling plays a crucial role in the locomotion of aquatic animals. Much attention has been given recently to understanding how aquatic animals use this coupling to their advantage, thus achieving impressive maneuvers and hydrodynamic efficiencies. These studies, in addition to their direct contribution to unraveling the physical mechanisms responsible for swimming, bear the potential of enabling novel engineering designs of autonomous underwater vehicles that move by shape undulation rather than by direct propulsion.
In this talk, we discuss basic mechanisms by which idealized bodies swim in a perfect fluid. We do not propose high-fidelity models of fish. We rather ask what are the minimum characteristics a submerged body should have in order to swim. We focus on two types of locomotion: (i) active locomotion due to controlled body deformations, and (ii) passive locomotion due to energy harvested from ambient vorticity. We also comment on the stability of motion in unsteady flows and the role of hydro-dynamic coupling in the motion coordination of multiple bodies.