Flapping wing flight can save aerodynamic power compared to steady flight.
Flapping flight is more maneuverable than steady flight. It is debated whether this advantage is necessarily accompanied by a trade-off in the flight efficiency. Here we ask if any flapping motion exists that is aerodynamically more efficient than the optimal steady motion. We solve the Navier-Stokes equation governing the fluid dynamics around a 2D flapping wing, and determine the minimal aerodynamic power needed to support a specified weight. While most flapping wing motions are more costly than the optimal steady wing motion, we find that optimized flapping wing motions can save up to 27% of the aerodynamic power required by the optimal steady flight. We explain the cause of this energetic advantage.
Pesavento
Umberto
U
Department of Theoretical and Applied Mechanics, Cornell University, Ithaca, New York 14853, USA.
Wang
Z Jane
ZJ
D001359:Aviation; D040761:Biomimetic Materials; D005426:Flight, Animal; D008962:Models, Theoretical