Meeting Abstract

P3-15   -   The effect of graded flexural rigidity on flapping wing insect flight performance Reade, JE*; Jankauski, M; Montana State University; Montana State University josephreade.school@gmail.com

Insect wings are highly nonuniform structures that exhibit significant spatial variation of flexural rigidity. This nonuniformity influences the wing’s deflection under inertial and aerodynamic loading, which in turn impacts its aerodynamic and energetic performance. However, the relationship between spatially dependent flexural rigidity and aerodynamic function is not well understood. In this work, we develop a reduced-order model of the flapping wing using the assumed mode method and unsteady vortex lattice method to model the structural and fluid dynamics, respectively. We use this model to investigate how flexural rigidity gradients affect the lift production, power consumption, and force needed to flap a Manduca sexta forewing across a range of kinematics. We find that lift production is maximized when flexural rigidity gradients cause a driving-to-natural frequency ratio of about 1/3, though the precise ratio varies with flapping kinematics. For hovering flapping kinematics, the optimized flexible wing produces higher lift-per-power than its rigid counterpart but requires larger forces to flap. The flexible wing continues to outperform the rigid wing in terms of lift and power requirements over a range of flexural rigidity distributions even when flapping kinematics diverge from those observed during hover. Wings with a stiffer leading edge generally require lower forces but higher mean power to flap compared to wings with homogenous stiffness. This may suggest a trade-off in insect flight, where increasing the forces necessary to flap reduces energetic expenditures but requires larger muscle mass.