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Flying insects are thought to achieve energy-efficient flapping flight by storing and releasing elastic energy in their muscles, tendons, and thorax. However, ‘spring-wing’ flight systems consisting of elastic elements coupled to nonlinear, unsteady aerodynamic forces present possible challenges to generating stable and responsive wing motion. The energetic efficiency from resonance in insect flight is tied to the Weis-Fogh number (N), which is the ratio of peak inertial force to aerodynamic force. In this paper, we present experiments and modeling to study how resonance efficiency (which increases withN) influences the control responsiveness and perturbation resistance of flapping wingbeats. In our first experiments, we provide a step change in the input forcing amplitude to a series-elastic spring-wing system and observe the response time of the wing amplitude increase. In our second experiments we provide an external fluid flow directed at the flapping wing and study the perturbed steady-state wing motion. We evaluate both experiments across Weis-Fogh numbers from 1 < N < 10. The results indicate that spring-wing systems designed for maximum energetic efficiency also experience trade-offs in agility and stability as the Weis-Fogh number increases. Our results demonstrate that energetic efficiency and wing maneuverability are in conflict in resonant spring-wing systems, suggesting that mechanical resonance presents tradeoffs in insect flight control and stability.
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The effect of flapping frequency on the aerodynamics of NACA0012 wing
Computational studies of transient three-dimensional flapping wing are carried out using the large eddy simulation (LES) approach. The studies concern the understanding of the effect of flapping motion on the aerodynamic performance and aeroacoustics noise of a finite NACA0012 wing. The flapping motion of the wing generates trailing-edge vortices whose magnitude and scale vary in time. The near-field flow is associated with periodic flow separation and reattachments, which cause a time-dependent aerodynamic coefficients.
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- Award ID(s):
- 1950207
- PAR ID:
- 10327365
- Editor(s):
- AIAA
- Date Published:
- Journal Name:
- AIAA SciTech 2021 Conference
- Issue:
- 2021-0342
- Format(s):
- Medium: X
- Sponsoring Org:
- National Science Foundation
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