Passive Pitching in Insect Flight
Attila Bergou
Department of Physics, Cornell University
Abstract:
As with conventional airfoils, the orientation of the wing to the oncoming flow, the angle of attack, is a kinematic parameter of utmost importance for a flapping wing. In fact, wing pitch reversal, the sudden change of angle of attack at the end of a stroke, represents a fundamental difference between hovering with flapping wings and with a continuously rotating blade (e.g. helicopter flight). Recently, by analyzing several previously published insect strokes, we have shown the surprising fact that insects are able to orient their wings energetically passively. We are expanding on this work with an experimental collaboration that has enabled us to capture the intricate motion of fruit flies at a level of detail that has previously been impossible. Using data from this experiment and direct numerical solutions of the Navier-Stokes equation I will show our progress towards understanding wing pitching in insect flight.