トンボの翅の変形特性が飛翔に与える影響

Abstract

Dragonflies have high flight performance in spite of small size. Therefore, applying flight mechanism of dragonfly to micro air vehicle is expected. One of the important thing for dragonfly flight is characteristics of wings. Dragonfly wing is passively deformed in the tip side from the nodus in flapping flight. Wing deformation is thought to correspond to feathering motion. However, dragonfly perform a feathering motion actively. It is necessary for development of MAV to understand the interaction between active and passive feathering. In this study, the effect of passive deformation of the wing on aerodynamic force in flapping flight with feathering motions was investigated using fluid-structure interaction analysis. In this analysis, nodus wing models, which can deform passively, and rigid wing model, which cannot deform, are used. Feathering angle is three types: 0, 20, and 40 deg. As a result, when the feathering angle is 20 deg or less, lift force of the nodus wings is increased. Moreover, drag force of the nodus wings is decreased when the feathering angle is 20 deg. However, when the feathering angle is 40 deg, overlarge deformation of wing decreases lift force and increases drag force. Power for flapping of nodus wings is reduced compared with rigid wing. In the case of straight flight, efficiency of lift is best when the feathering angle is 20 deg and nodus is located near the center of wings.