Review article: On the diverse roles of fluid dynamic drag in animal swimming and flying

R. Godoy-Diana & B. Thiria. J. Roy. Soc. Interface 15 20170715 (2018)
[doi:10.1098/rsif.2017.0715]

When a body moves through a fluid, drag is often thought as a dissipative source that has perpetually to be overcome to sustain motion injecting new energy. In animal locomotion, the role of hydrodynamic drag is actually subtler and presents several interesting features acting in favour of the propulsion mechanisms. In this paper, we review recent significant results on the different physical mechanisms that govern the magnitude of drag as a function of the speed at which the animal is moving; and show how drag forces act locally to determine the kinematics and propulsive force production in animals or bio-inspired systems.