How to swim in a perfect fluid



Eva Kanso


Department of Aerospace and Mechanical Engineering 

University of Southern California



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. 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 requirements in order for a submerged body 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 comment on the stability of motion in unsteady flows and the role of hydro-dynamic coupling in the motion coordination of multiple bodies.