April 28, 2009 (Tuesday)
11:00 am in Howey N110

"Insects in Free Flight:

Aerodynamics, Optimization, and Control"

Jane Wang, Cornell University

Animals, small and large, must solve the problem of locomotion in order to survive. Insects  offer some of the most ingenious solutions to locomotion. To understand the works of nature, our approach is to 'take an insect apart' and then put different pieces back together. We started from the outer scale, where insect wings are immersed in fluids. To stay aloft, an insect wing must solve the problem of unsteady aerodynamics. What kind of flow and forces does a flapping wing generate? How are flows and forces similar and different from those around and on an airfoil? Exactly when does the classical aerodynamic theory become inapplicable?  In theory, there are infinitely many ways an insect can flap its wings to stay aloft. How do insects move their wings to generate sufficient forces? What is special about the way insects move their wings? Why do seemingly different insects use similar wing motions, whereas some insects use drastically different wing motions? Do insects care about energetic efficiency? At the inner scale, the wings are driven by the muscles, and the muscles are controlled by insect's brain. Can we infer about the effective muscle actions from the dynamics of the wing and body?  Are flapping flight dynamically stable? Can we deduce an effective control algorithms that insects use to turn and to maneuver? Have insects evolved to minimize energetic cost and simplify
control?  In this talk I will describe the  results in answering some of these questions. In particular, I will focus on dragonfly flight and our current effort in understanding the dynamics and control of insects in free flight.