Global-local optimization of flapping kinematics in hovering flight

Abstract
The kinematics of a hovering wing are optimized by combining the 2-d unsteady vortex lattice method with a hybrid of global and local optimization algorithms. The objective is to minimize the required aerodynamic power under a lift constraint. The hybrid optimization is used to efficiently navigate the complex design space due to wing-wake interference present in hovering aerodynamics. The flapping wing is chosen so that its chord length and flapping frequency match the morphological and flight properties of two insects with different masses. The results suggest that imposing a delay between the different oscillatory motions defining the flapping kinematics, and controlling the way through which the wing rotates at the end of each half stroke can improve aerodynamic power under a lift constraint. Furthermore, our optimization analysis identified optimal kinematics that agree fairly well with observed insect kinematics, as well as previously published numerical results.

Citation
Ghommem, M., Hajj, M. R., Mook, D. T., Stanford, B. K., Beran, P. S., & Watson, L. T. (2013). Global-Local Optimization of Flapping Kinematics in Hovering Flight. International Journal of Micro Air Vehicles, 5(2), 109–126. doi:10.1260/1756-8293.5.2.109

Acknowledgements
Support of the Air Force Research Laboratory under Contract FA 8650-09-02-3938 is acknowledged. The authors are grateful to Prof. Svanberg who kindly supplied us the optimization package GCMMA, Prof. Nuhait who provided us the results reported in Figure 2, and finally H. Taha of Virginia Tech for his help in discussing the physics of the optimized hovering kinematics.

Publisher
SAGE Publications

Journal
International Journal of Micro Air Vehicles

DOI
10.1260/1756-8293.5.2.109

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