Flapping insect flight generates high mean lift by the interaction of the wings with the shed vorticity. Typical Reynolds numbers of insects are around 5000. The high lift of an insect is not usually explained by conventional quasi-steady aerodynamics. In this study, we compute unsteady viscous flows, governed by the Navier-Stokes equation, about a flapping wing, which undergoes various translational and rotational motions. We show an optimal range of flapping frequency, which results from the unsteady effect and the dynamics of both the leading and trailing edge vortices. We further offer a simple physical picture of the frequency selection mechanism.

Back to Workshop Schedule

1998-1999 Mathematics in Biology