Meeting Abstract

P2.158  Tuesday, Jan. 5  The Effects of Wing Flexibility on Small Insect Flight BROWNING, J. A.*; SANTHANAKRISHNAN, A.; MILLER, L. A.; University of North Carolina-Chapel Hill; University of North Carolina-Chapel Hill; University of North Carolina-Chapel Hill jamesb@unc.edu

Previous work on insect flight has focused on larger insects (Re>100) where the effects of viscosity can largely be ignored. Only a few studies have examined the smaller insects that fly at Reynolds numbers below 100. This work has shown, however, that the flight kinematics and aerodynamics of these insects can be significantly different from those that fly at higher Reynolds numbers. In our project, we focused on flexible wing rotation at Reynolds numbers below 100 using dynamically scaled physical models. The model wing was immersed in a tank and attached to a motor via a shaft mounted on the top of the tank. Low Reynolds numbers were achieved using various mixtures of glycerin and water. We measured the flow velocities around the wings using both flexible and stiff wings in root rotation with digital particle image velocimetry (DPIV). We find that at Reynolds numbers below ~40 both leading and trailing edge vortices do not separate from the wing. In addition, the circulation strengths of these vortices appear to depend on wing stiffness.