Abstract
Flying insects can achieve smart maneuverability, such as rapid acceleration, deceleration, and hovering under complex environmental disturbances. Previous studies suggest that there may exist a delay of two wingbeat cycles for insects to actively tune their wing kinematics in response of disturbances. Such delay may degrade the dynamic flight stability of flapping-wing flights. And it is considerable that insects may use some passive mechanisms in terms of wing flexibility to enhance the flight stability in disturbances. In this study, we carried out a numerical study of hawkmoth hovering flight stability with a focus on how steady and unsteady disturbances affect the body attitudes by performing a fluid-structure interaction simulation of flexible wings in flapping. Our impedimentary FSI results indicate that the bending of the flexible wing in a steady flow seems to be responsible for augmenting the generation of vertical and horizontal forces while reducing the variation of the aerodynamics torques. These results point out to the importance of wing flexibility in enhancing the flapping-wing flight stability in disturbances.
