WING GEOMETRY AND DYNAMIC SIMILARITY IN INSECT FLIGHT

摘要

The study of insect and bird flight has always been a curiosity, but it is yet to be described as plentifully as fixed wing aerodynamics. The United States military has expressed an interest in this topic, providing some institutions with funding. The main intention for this type of research is to develop small robots resembling insects or birds for use in exploration, surveillance and intelligence. While conceptually these applications could be accomplished with fixed-wing aircraft, there is a tremendous lack of stealth in these vehicles. The velocities associated with the required lift forces for small flapping-wing insect flights are significantly smaller than for insect-size fixed-wing aircraft. Therefore, it is more feasible and practical to aim for flapping wing flight. There have been studies in which wing beat frequencies of some birds are predicted as a function of mass and other physical characteristics (Pennycuick, 1996). Other studies such as Liu and Kawachi, 1998 have taken a more theoreticalumerical approach using a time accurate solution of the three-dimensional Navier-Stokes equations. A number of parameters such as power needed, power produced, mass supported, and others, have been determined for hovering flight of bumblebees and the hawkmoth manduca. In this study a scaled prototype is being built based on the physical characteristics of a hawkmoth manduca during hovering flight. It is reasonable that if a prototype is designed for hovering flight where the power requirements are highest, that it will sustain flight in other situations. The focus of this project is to analyze different wing geometries in a scaled model of a hawkmoth manduca, and see how these affect flight.