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 102 and 104, 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: 1) the existence of a preferred frequency in forward flight and its physical origin, and 2) the vortex dynamics and unsteady forces in hovering dragonfly flight. If time permits, I will show the recent results on three dimensional flapping flight driven by muscles.
Hosted by Elizabeth Bradley.
This talk is being held jointly with the College Committee on Bioengineering and the Departments of Aerospace Engineering, Mechanical Engineering, and Applied Math.
Refreshments will be served immediately following the talk in ECOT 831.