Abstract
In the present study, we perform a wind-tunnel experiment to investigate the aerodynamic performance of a gliding swallowtail-butterfly wing model having a low aspect ratio. The drag, lift and pitching moment are directly measured using a 6-axis force/torque sensor. The lift coefficient increases rapidly at attack angles less than 10° and then slowly at larger attack angles. The lift coefficient does not fall off rapidly even at quite high angles of attack, showing the characteristics of low-aspect-ratio wings. On the other hand, the drag coefficient increases more rapidly at higher angles of attack due to the increase in the effective area responsible for the drag. The maximum lift-to-drag ratio of the present modeled swallowtail butterfly wing is larger than those of wings of fruitfly and bumblebee, and even comparable to those of wings of birds such as the petrel and starling. From the measurement of pitching moment, we show that the modeled swallowtail butterfly wing has a longitudinal static stability. Flow visualization shows that the flow separated from the leading edge reattaches on the wing surface at α < 15°, forming a small separation bubble, and full separation occurs at α ≥ 15°. On the other hand, strong wing-tip vortices are observed in the wake at α ≥ 5° and they are an important source of the lift as well as the main reason for broad stall. Finally, in the absence of long hind-wing tails, the lift and longitudinal static stability are reduced, indicating that the hind-wing tails play an important role in enhancing the aerodynamic performance.
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References
Shyy W, Lian Y, Tang J, Viieru D, Liu H (2008) Aerodynamics of low reynolds number flyers. Cambridge University Press, New York
Brodsky AK (1994) The evolution of insect flight. Oxford University Press, New York
Dudley R (2000) The biomechanics of insect flight. Form, function, evolution. Princeton University Press, Princeton
Gibo DL, Pallett MJ (1979) Soaring flight of monarch butterflies, Danaus Plexippus (Lepidoptera: Danaidae), during the late summer migration in southern Ontario. Can J Zool 57:1393–1401
Preston-Mafham R, Preston-Mafham K (2004) Butterflies of the world. Facts on File, New York
Brodsky AK (1991) Vortex formation in the tethered flight of the peacock butterfly Inachis Io L. (Lepidoptera, Nymphalidae) and some aspects of insect flight evolution. J Exp Biol 161:77–95
Ellington CP, van den Berg C, Willmott AP, Thomas ALR (1996) Leading-edge vortices in insect flight. Nature 384:626–630
Srygley RB, Thomas ALR (2002) Unconventional lift-generating mechanisms in free-flying butterflies. Nature 420:660–664
Nachtigall W (1976) Wing movements and the generation of aerodynamic forces by some medium-sized insects. In: Rainey RC (ed) Insect flight. Blackwell Scientific Publications, Oxford, pp 31–47
Buckholz RH (1986) The functional role of wing corrugations in living systems. J Fluids Eng 108:93–97
Wootton RJ (1993) Leading edge section and asymmetric twisting in the wings of flying butterflies (Insecta, Papilionoidea). J Exp Biol 180:105–117
Berwaerts K, van Dyck H, Aerts P (2002) Does flight morphology relate to flight performance? An experimental test with the butterfly Pararge aegeria. Funct Ecol 16:484–491
Betts CR, Wootton RJ (1988) Wing shape and flight behaviour in butterflies (Lepidoptera: Papilionoidea and Hesperioidea): a preliminary analysis. J Exp Biol 138:271–288
Martin LJ, Carpenter PW (1977) Flow-visualization experiments on butterflies in simulated gliding flight. In: Nachtigall W (ed) The physiology of movement: biomechanics. Fischer, Stuttgart, pp 307–315
Nachtigall W (1974) Insects in flight. McGraw-Hill, New York
Cech R, Tudor G (2005) Butterflies of the East Coast: an observer’s guide. Princeton University Press, Princeton
Barlow JB, Rae WH Jr, Pope A (1999) Low-speed wind tunnel testing. Wiley, New York
Mueller TJ, Torres GE (2001) Aerodynamic characteristics of low aspect ratio wings at low Reynolds numbers. In: Fixed and flapping wing aerodynamics for micro air vehicle applications. American Institute of Aeronautics and Astronautics, Inc., Virginia, pp 115–141
Thomas ALR, Taylor GK (2001) Animal flight dynamics I. Stability in gliding flight. J Theor Biol 212:399–424
Wakeling JM, Ellington CP (1997) Dragonfly flight I. Gliding flight and steady-state aerodynamic forces. J Exp Biol 200:543–556
Vogel S (1967) Flight in drosophila III. Aerodynamic characteristics of fly wings and wing models. J Exp Biol 46:431–443
Jensen M (1956) Biology and physics of locust flight III. The aerodynamics of locust flight. Philos Trans R Soc Lond B 239:511–552
Withers PC (1981) An aerodynamic analysis of bird wings as fixed aerofoils. J Exp Biol 90:143–162
Dudley R, Ellington CP (1990) Mechanics of forward flight in bumblebees II. Quasi-steady lift and power requirements. J Exp Biol 148:53–88
Nachtigall W (1977) Die Aerodynamische Polare des Tipula-Flugels undeine Einrichtung zur halbautomatischen Polarenaufnahme. In: Nachtigall W (ed) The physiology of movement: biomechanics. Fischer, Stuttgart, pp 347–352
Willmott AP, Ellington CP (1997) The mechanics of flight in the hawkmoth Manduca sexta. 2. Aerodynamic consequences of kinematic and morphological variation. J Exp Biol 200:2723–2745
Vogel S (1994) Life in moving fluids. Princeton University Press, Princeton
Lian Y, Shyy W (2003) Three-dimensional fluid-structure interactions of a membrane wing for micro air vehicle applications. AIAA Paper 2003-1726
Mueller TJ, DeLaurier JD (2003) Aerodynamics of small vehicles. Annu Rev Fluid Mech 35:89–111
Hoerner SF (1985) Fluid-dynamic lift. Hoerner, Bakersfield
Williamson CHK (1985) Evolution of a single wake behind a pair of bluff bodies. J Fluid Mech 159:1–18
Kang S (2003) Characteristics of flow over two circular cylinders in a side-by-side arrangement at low Reynolds numbers. Phys Fluids 15:2486–2498
Kolar V, Lyn DA, Rodi W (1997) Ensemble-averaged measurements in the turbulent near wake of two side-by-side square cylinders. J Fluid Mech 346:201–237
Sumner D, Wong SST, Price SJ, Paidoussis MP (1999) Fluid behavior of side-by-side circular cylinder in steady cross-flow. J Fluids Struct 13:309–338
Zdravkovich MM (2003) Flow around circular cylinders vol. 2: applications. Oxford University Press, New York
Zhou Y, Zhang HJ, Yiu MW (2002) The turbulence wake of two side-by-side circular cylinders. J Fluid Mech 458:303–332
Acknowledgments
This work was supported by the National Research Laboratory Program of Ministry of Education, Science and Technology, Korea (R0A-2006-000-10180-0). This work was also partly supported by the Korea Research Foundation Grant (MOEHRD; KRF-J03001) and the WCU Program (R31-2008-000-10083-0).
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Park, H., Bae, K., Lee, B. et al. Aerodynamic Performance of a Gliding Swallowtail Butterfly Wing Model. Exp Mech 50, 1313–1321 (2010). https://doi.org/10.1007/s11340-009-9330-x
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DOI: https://doi.org/10.1007/s11340-009-9330-x