Abstract
Dragonfly flight is one of the best models of small air craft called Micro Air Vehicle (MAV). For development of dragonfly-like MAV, the deformation characteristics of wings are important. Dragonfly wing is easy to be passively deformed in the tip side from the nodus, and thereby, aerodynamic force is generated effectively. In this study, aerodynamic characteristics of flexible wing like a dragonfly wing was investigated in both gliding flight and flapping flight using fluid-structure interaction analysis. In this analysis, nodus wing model that is deformed in the tip side are used as flexible wing. As a result, in case of gliding flight, the lift coefficient of the nodus wing was lower in low-angle of attack and was higher in high-angle of attack compared to inflexible wing. Therefore, flexible wing is less suitable for the gliding flight than inflexible wing because gliding flight is low-angle of attack usually. In case of flapping flight, the nodus wing made drag forces generated during downstroke lower compared with inflexible wing. On the other hand, thrust forces generated during upstroke were the same in both wings. Therefore, flexible wing is more suitable for flapping flight than inflexible wing. The wings of dragonfly-like MAV need to appropriate level of flexibility.
