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Dynamic pitching of an elastic rectangular wing in hovering motion

Published online by Cambridge University Press:  17 January 2012

Hu Dai
Affiliation:
Department of Mechanical Engineering, Vanderbilt University, 2301 Vanderbilt Place, Nashville, TN 37235-1592, USA
Haoxiang Luo*
Affiliation:
Department of Mechanical Engineering, Vanderbilt University, 2301 Vanderbilt Place, Nashville, TN 37235-1592, USA
James F. Doyle
Affiliation:
School of Aeronautics and Astronautics, Purdue University, West Lafayette, IN 47907-2045, USA
*
Email address for correspondence: haoxiang.luo@vanderbilt.edu

Abstract

In order to study the role of the passive deformation in the aerodynamics of insect wings, we computationally model the three-dimensional fluid–structure interaction of an elastic rectangular wing at a low aspect ratio during hovering flight. The code couples a viscous incompressible flow solver based on the immersed-boundary method and a nonlinear finite-element solver for thin-walled structures. During a flapping stroke, the wing surface is dominated by non-uniform chordwise deformations. The effects of the wing stiffness, mass ratio, phase angle of active pitching, and Reynolds number are investigated. The results show that both the phase and the rate of passive pitching due to the wing flexibility can significantly modify the aerodynamics of the wing. The dynamic pitching depends not only on the specified kinematics at the wing root and the stiffness of the wing, but also greatly on the mass ratio, which represents the relative importance of the wing inertia and aerodynamic forces in the wing deformation. We use the ratio between the flapping frequency, , and natural frequency of the wing, , as the non-dimensional stiffness. In general, when , the deformation significantly enhances the lift and also improves the lift efficiency despite a disadvantageous camber. In particular, when the inertial pitching torque is assisted by an aerodynamic torque of comparable magnitude, the lift efficiency can be markedly improved.

Type
Papers
Copyright
Copyright © Cambridge University Press 2012

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References

1. Bai, P., Cui, E. & Zhan, H. 2009 Aerodynamic characteristics, power requirements and camber effects of the pitching-down flapping hovering. J. Bionic Engng 6 (2), 120134.CrossRefGoogle Scholar
2. Batoz, J. L., Bathe, K. J. Ü. R. & Ho, L. W. 1980 A study of three-node triangular plate bending elements. Intl J. Numer. Meth. Engng 15 (12), 17711812.CrossRefGoogle Scholar
3. Birch, J. M. & Dickinson, M. H. 2001 Spanwise flow and the attachment of the leading-edge vortex on insect wings. Nature 412, 729.CrossRefGoogle Scholar
4. Chen, J. S., Chen, J. Y. & Chou, Y. F. 2008 On the natural frequencies and mode shapes of dragonfly wings. J. Sound Vib. 313, 643654.CrossRefGoogle Scholar
5. Combes, S. A. & Daniel, T. L. 2003 Into thin air: contributions of aerodynamic and inertial-elastic forces to wing bending in the hawkmoth manduca sexta. J. Expl Biol. 206, 29993006.CrossRefGoogle Scholar
6. Dickinson, M. H., Lehmann, F.-O. & Sane, S. P. 1999 Wing rotation and the aerodynamic basis of insect flight. Science 284, 1954.CrossRefGoogle ScholarPubMed
7. Dong, H., Mittal, R. & Najjar, F. M. 2006 Wake topology and hydrodynamic performance of low-aspect-ratio flapping foils. J. Fluid Mech. 566, 309343.CrossRefGoogle Scholar
8. Doyle, J. F. 1991 Static and Dynamic Analysis of Structures. Kluwer.CrossRefGoogle Scholar
9. Doyle, J. F. 2001 Nonlinear Analysis of Thin-walled Structures: Statics, Dynamic, and Stability. Springer.CrossRefGoogle Scholar
10. Doyle, J. F. 2008 QED: Static, Dynamic, Stability, and Nonlinear Analysis of Solids and Structures. Software manual, version 4.60.Google Scholar
11. Eldredge, J. D., Toomey, J. & Medina, A. 2010 On the roles of chord-wise flexibility in a flapping wing with hovering kinematics. J. Fluid Mech. 659, 94115.CrossRefGoogle Scholar
12. Ellington, C. P., Berg, C. V., Willmott, A. P. & Thomas, A. L. R. 1996 Leading-dege vortices in insect flight. Nature 384, 626.CrossRefGoogle Scholar
13. Ennos, A. R. 1988a The importance of torsion in the design of insect wings. J. Expl Biol. 140, 137160.CrossRefGoogle Scholar
14. Ennos, A. R. 1988b The inertial cause of wing rotation in diptera. J. Expl Biol. 140, 161169.CrossRefGoogle Scholar
15. Heathcote, S. & Gursul, I. 2007 Flexible flapping airfoil propulsion at low Reynolds numbers. AIAA J. 45, 10661079.CrossRefGoogle Scholar
16. Hedrick, T. L., Cheng, B. & Deng, X. 2009 Wingbeat time and the scaling of passive rotational damping in flapping flight. Science 324 (5924), 252255.CrossRefGoogle ScholarPubMed
17. Kang, C., Aono, H., Cesnik, C. E. S. & Shyy, W. 2011 Effects of flexibility on the aerodynamic performance of flapping wings. AIAA Paper 2011–3121.CrossRefGoogle Scholar
18. Kweon, J. & Choi, H. 2010 Sectional lift coefficient of a flapping wing in hovering motion. Phys. Fluids 22, 071703.CrossRefGoogle Scholar
19. Luo, H., Dai, H., Ferreira de Sousa, P. & Yin, B. 2011 On the numerical oscillation of the direct-forcing immersed-boundary method for moving boundaries. Comput. Fluids, doi:10.1016/j.compfluid.2011.11.015.CrossRefGoogle Scholar
20. Luo, H., Yin, B., Dai, H. & Doyle, J. F. 2010 A 3D computational study of the flow–structure interaction in flapping flight. AIAA Paper 2010-556.CrossRefGoogle Scholar
21. Mittal, R., Dong, H., Bozkurttas, M., Najjar, F. M., Vargas, A. & von Loebbeck, A. 2008 A versatile sharp interface immersed boundary method for incompressible flows with complex boundaries. J. Comput. Phys. 227 (10), 48254852.CrossRefGoogle ScholarPubMed
22. Prempraneerach, P., Hover, F. S. & Triantafyllou, M. S. 2003 The effect of chordwise flexibility on the thrust and efficiency of a flapping foil. In Proc. 13th Intl Symp. on Unmanned Untethered Submersible Technology: Special Session on Bioengineering Research Related to Autonomous Underwater Vehicles, 24–27 August, Durham, NH.Google Scholar
23. Ramananarivo, S., Godoy-Diana, R. & Thiria, B. 2011 Rather than resonance, flapping wing flyers may play on aerodynamics to improve performance. Proc. Natl Acad. Sci. 108 (15), 5964.CrossRefGoogle ScholarPubMed
24. Sun, M. & Tang, J. 2002 Unsteady aerodynamic force generation by a model fruit fly wing in flapping motion. J. Expl Biol. 205 (17), 55.CrossRefGoogle Scholar
25. Taira, K. & Colonius, T. 2009 Three-dimensional flows around low-aspect-ratio flat-plate wings at low Reynolds numbers. J. Fluid Mech. 623, 187207.CrossRefGoogle Scholar
26. Triantafyllou, M. S., Techet, A. H. & Hover, F. S. 2004 Review of experimental work in biomimetic foils. IEEE J. Ocean. Engng 29 (3), 585594.CrossRefGoogle Scholar
27. Vanella, M., Fitzgerald, T., Preidikman, S., Balaras, E. & Balachandran, B. 2009 Influence of flexibility on the aerodynamic performance of a hovering wing. J. Expl Biol. 212, 96105.CrossRefGoogle ScholarPubMed
28. Walker, S. M., Thomas, A. L. R. & Taylor, G. K. 2010 Deformable wing kinematics in free-flying hoverflies. J. R. Soc. Interface 7, 131142.CrossRefGoogle ScholarPubMed
29. Wang, H., Zeng, L., Liu, H. & Yin, C. 2003 Measuring wing kinematics, flight trajectory and body attitude during forward flight and turning maneuvers in dragonflies. J. Expl Biol. 206 (4), 745.CrossRefGoogle ScholarPubMed
30. Wang, Z. J. 2005 Dissecting insect flight. Annu. Rev. Fluid Mech. 37, 183210.CrossRefGoogle Scholar
31. Wang, Z. J., Birch, J. M. & Dickinson, M. H. 2004 Unsteady forces and flows in low Reynolds number hovering flight: two-dimensional computations vs robotic wing experiments. J. Expl Biol. 207, 449460.CrossRefGoogle ScholarPubMed
32. Wootton, R. J. 1981 Support and deformability in insect wings. J. Zool. 193 (4), 447468.CrossRefGoogle Scholar
33. Wootton, R. J. 1992 Functional morphology of insect wings. Annu. Rev. Entomol. 37 (1), 113140.CrossRefGoogle Scholar
34. Yin, B. & Luo, H. 2010 Effect of wing inertia on hovering performance of flexible flapping wings. Phys. Fluids 22, 111902.CrossRefGoogle Scholar