Unsteady Aerodynamics of Insect Flight
Jane Wang
Theoretical and Applied Mechanics, 212 Kimball Hall, Cornell University,
Ithaca, NY 14853, USA
Abstract:
Interactions between dynamic boundaries and unsteady
viscous flows occur in a wide range of physical, engineering,
and biological systems, including fish swimming and insect flight.
These problems pose formidable theoretical and computational
challenges, due to the tight coupling between the dynamics
of the boundary and the fluid, and the presence of multiple
interacting time and length scales. On the other hand,
Nature has been solving the same problem over millions
of years. In a sense, insects are nature's Navier-Stokes
solvers, and no doubt they have found some clever answers
in the course of evolution. Therefore, studies of the
unsteady aerodynamics of insect flight will advance our
fundamental understanding of one of most challenging subjects
in fluid dynamics.
In this talk I report our recent work on computing and modeling
of insect flight. We compute unsteady viscous flows, governed by
the Navier-Stokes equation, about a two dimensional flapping wing
which mimics the motion of an insect wing. I will present two main
results: the existence of a prefered frequency in forward flight and
its physical origin, and 2) the vortex dynamics and forces in hovering
dragonfly flight. If time permits, I will show the recent results on
three dimensional flapping flight driven by muscles.