Unsteady Aerodynamics of Insect Flight
Jane Wang
The myth `bumble-bees can not fly according to conventional
aerodynamics' simply reflects our poor understanding of
unsteady viscous fluid dynamics. In particular, we lack a
theory of vorticity shedding due to dynamic boundaries at
the intermediate Reynolds numbers relevant to insect flight,
typically between 10^2 and 10^4, where both
viscous and inertial effects are important. In our study,
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 preferred 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 comparing our computational results
against robotic fruitfly experiments and modeling three
dimensional flapping flight driven by muscles.