The Effect of Unsteady Flapping Motion on the Aerodynamic Performance of Bio-Inspired Alula
Publication: Journal of Aerospace Engineering
Volume 35, Issue 3
Abstract
Avian flight has inspired scientists and engineers for a long time. Flapping-wing micro air vehicle (FMAV) is a kind of air vehicle mimicking the avian flapping flight that has achieved great success in this century. However, in some complex flight conditions, its flight performance is not as good as that of birds. Birds have evolved many unique features to adapt to different and complex situations. The leading-edge alula is considered a typical structure that can enhance birds’ flight capabilities in slow-speed flight. In this paper, we numerically investigate the effects of bionic alula on the aerodynamic performance of flapping airfoil under different flapping kinematic parameters. The influence of different pitch amplitudes, plunge amplitudes, and mean angles of attack (AoAs) of freestream are considered. Results show that the deflection of the alula will suppress the flow separation and restrain the formation and development of the leading-edge vortex (LEV). This will cause a significant discrepancy in aerodynamic performances between the airfoil with and without bionic alula. Observing their different flow structures, the time-averaged lift coefficient of the single flapping airfoil without alula first decreases then increases with the increasing pitch amplitude, but almost increases continuously with the rising plunge amplitude. However, as for the airfoil with alula, the time-averaged lift coefficient first rises then drops as the pitch amplitude increases, and also first rises then falls with the increasing plunge amplitude. The maximum enhancement of the alula on the time-averaged lift coefficient can reach 82.2% under the optimum kinematic parameters. The bionic alula can also delay stall, and the stall angle postpones by 7° in the scope of our research.
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Data Availability Statement
Some or all data, models, or code that support the findings of this study are available from the corresponding author upon reasonable request.
Acknowledgments
This work was supported in part by the National Natural Science Foundation of China under Grant Nos. 11872314 and No. 11902103 and Key R&D Program in Shaanxi Province of China (2020GY-154).
References
Álvarez, J. Z., J. Meseguer, E. Meseguer, and G. I. Perez. 2001. “On the role of the alula in the steady flight of birds.” Ardeola 48 (2): 161–173.
Ashraf, M. A., J. Young, and J. C. S. Lai. 2012. “Oscillation frequency and amplitude effects on plunging airfoil propulsion and flow periodicity.” AIAA J. 50 (11): 2308–2324. https://doi.org/10.2514/1.J051374.
Austin, B., and A. M. Anderson. 2007. “The alula and its aerodynamic effect on avian flight.” In Proc., ASME 2007 Int. Mechanical Engineering Congress and Exposition. New York: ASME.
Bao, H., W. Q. Yang, D. F. Ma, W. P. Song, and B. F. Song. 2020. “Numerical simulation of flapping airfoil with alula.” Int. J. Micro Air Veh. 12 (Nov): 1–15. https://doi.org/10.1177/1756829320977989.
Berg, A. M., and A. A. Biewener. 2010. “Wing and body kinematics of takeoff and landing flight in the pigeon (Columba livia).” J. Exp. Biol. 213 (10): 1651–1658. https://doi.org/10.1242/jeb.038109.
Birch, J. M., and M. H. Dickinson. 2003. “The influence of wing–wake interactions on the production of aerodynamic forces in flapping flight.” J. Exp. Biol. 206 (13): 2257–2272. https://doi.org/10.1242/jeb.00381.
Carruthers, A. C., A. L. R. Thomas, and G. K. Taylor. 2007. “Automatic aeroelastic devices in the wings of a steppe eagle Aquila nipalensis.” J. Exp. Biol. 210 (23): 4136–4149. https://doi.org/10.1242/jeb.011197.
Cho, H., S. Shin, N. Lee, and S. Lee. 2019. “Computational study of fluid-structure interaction on flapping wing under passive pitching motion.” J. Aerosp. Eng. 32 (4): 04019023. https://doi.org/10.1061/(ASCE)AS.1943-5525.0001011.
Choi, H., H. Park, W. Sagong, and S. Lee. 2012. “Biomimetic flow control based on morphological features of living creatures.” Phys. Fluids 24 (12): 121302. https://doi.org/10.1063/1.4772063.
Cleaver, D. J., Z. Wang, I. Gursul, and M. R. Visbal. 2011. “Lift enhancement by means of small-amplitude airfoil oscillations at low Reynolds numbers.” AIAA J. 49 (9): 2018–2033. https://doi.org/10.2514/1.J051014.
Dickinson, M. H., F. O. Lehmann, and S. P. Sane. 1999. “Wing rotation and the aerodynamic basis of insect flight.” Science 284 (5422): 1954–1960. https://doi.org/10.1126/science.284.5422.1954.
Ellington, C. P., C. Van Den Berg, A. P. Willmott, and A. L. Thomas. 1996. “Leading-edge vortices in insect flight.” Nature 384 (6610): 626–630. https://doi.org/10.1038/384626a0.
Festo. 2011. “SmartBird, bird flight deciphered.” Accessed February 7, 2022. https://www.festo.com/us/en/e/about-festo/research-and-development/bionic-learning-network/highlights-from-2010-to-2012/smartbird-id_33686/.
Geng, F., I. Kalman, A. S. J. Suiker, and B. Blocken. 2018. “Sensitivity analysis of airfoil aerodynamics during pitching motion at a Reynolds number of .” J. Wind Eng. Ind. Aerodyn. 183 (Dec): 315–332. https://doi.org/10.1016/j.jweia.2018.11.009.
Gharali, K., and D. A. Johnson. 2013. “Dynamic stall simulation of a pitching airfoil under unsteady freestream velocity.” J. Fluids Struct. 42 (Oct): 228–244. https://doi.org/10.1016/j.jfluidstructs.2013.05.005.
Ghosh, S. K., C. L. Dora, and D. Das. 2012. “Unsteady wake characteristics of a flapping wing through 3D TR-PIV.” J. Aerosp. Eng. 25 (4): 547–558. https://doi.org/10.1061/(ASCE)AS.1943-5525.0000185.
Ishihara, D., T. Horie, and M. Denda. 2009. “A two-dimensional computational study on the fluid–structure interaction cause of wing pitch changes in dipteran flapping flight.” J. Exp. Biol. 212 (1): 1–10. https://doi.org/10.1242/jeb.020404.
Ito, M. R., C. Duan, and A. A. Wissa. 2019. “The function of the alula on engineered wings: A detailed experimental investigation of a bioinspired leading-edge device.” Bioinspiration Biomimetics 14 (5): 056015. https://doi.org/10.1088/1748-3190/ab36ad.
Karbasian, H. R., and C. K. Kyung. 2016. “Numerical investigations on flow structure and behavior of vortices in the dynamic stall of an oscillating pitching hydrofoil.” Ocean Eng. 127: 200–211. https://doi.org/10.1016/j.oceaneng.2016.10.005.
Katzmayr, R. 1922. Effect of periodic changes of angle of attack on behavior of airfoils. Washington, DC: National Advisory Committee for Aeronautics.
Lee, S. I., J. Kim, H. Park, P. G. Jablonski, and H. Choi. 2015. “The function of the alula in avian flight.” Sci. Rep. 5 (9914): 1–5. https://doi.org/10.1038/srep09914.
Lee, T., and P. Gerontakos. 2004. “Investigation of flow over an oscillating airfoil.” J. Fluid Mech. 512 (Aug): 313–341. https://doi.org/10.1017/S0022112004009851.
Li, X., H. F. Li, and Y. Zhen. 2019. “Flow mechanism for the effect of pivot point on the aerodynamic characteristics of a pitching airfoil and its manipulation.” Phys. Fluids 31 (8): 087108. https://doi.org/10.1063/1.5114833.
Linehan, T., and K. Mohseni. 2019. “Investigation of a sliding alula for control augmentation of lifting surfaces at high angles of attack.” Aerosp. Sci. Technol. 87 (Apr): 73–88. https://doi.org/10.1016/j.ast.2019.02.008.
Linehan, T., and K. Mohseni. 2020. “Scaling trends of bird’s alular feathers in connection to leading-edge vortex flow over hand-wing.” Sci. Rep. 10 (1): 7905. https://doi.org/10.1038/s41598-020-63181-7.
Liu, T., K. Kuykendoll, R. Rhew, and S. Jones. 2004. “Avian wings.” In Proc., 24th AIAA Aerodynamic Measurement Technology and Ground Testing Conf. Reston, VA: American Institute of Aeronautics and Astronautics.
Liu, T., K. Kuykendoll, R. Rhew, and S. Jones. 2006. “Avian wing geometry and kinematics.” AIAA J. 44 (5): 954–963. https://doi.org/10.2514/1.16224.
Mandadzhiev, B. A., M. K. Lynch, L. P. Chamorro, and A. A. Wissa. 2016. “Alula-inspired leading edge device for low Reynolds number flight.” In Proc., ASME 2016 Conf. on Smart Materials, Adaptive Structures and Intelligent Systems. New York: ASME.
Mandadzhiev, B. A., M. K. Lynch, L. P. Chamorro, and A. A. Wissa. 2017. “An experimental study of an airfoil with a bio-inspired leading edge device at high angles of attack.” Smart Mater. Struct. 26 (9): 094008. https://doi.org/10.1088/1361-665X/aa7dcd.
McCroskey, W. J., L. W. Carr, and K. W. McAlister. 1976. “Dynamic stall experiments on oscillating airfoils.” AIAA J. 14 (1): 57–63. https://doi.org/10.2514/3.61332.
Meseguer, J., J. C. Álvarez, E. Meseguer, and A. Pérez. 2003. The alula: A leading edge, high lift device of birds. Madrid, Spain: Ignacio Da Riva/Universidad Politécnica de Madrid.
Meseguer, J., S. Franchini, G. I. Perez, and J. L. Sanz. 2005. “On the aerodynamics of leading-edge high-lift devices of avian wings.” Proc. Inst. Mech. Eng., Part G: J. Aerosp. Eng. 219 (1): 63–68. https://doi.org/10.1243/095441005X9067.
Nachtigall, W., and B. Kempf. 1971. “Vergleichende untersuchungen zur flugbiologischen funktion des Daumenfittichs (Alula spuria) bei vögeln.” Z. Vergleichende Physiol. 71 (3): 326–341. https://doi.org/10.1007/BF00298144.
Nicola, C., D. J. Cleaver, and I. Gursul. 2017. “Unsteady measurements for a periodically plunging airfoil.” In Proc., 55th AIAA Aerospace Sciences Meeting. Reston, VA: American Institute of Aeronautics and Astronautics.
Percin, M., B. W. Oudheusden, G. Croon, and B. Remes. 2016. “Force generation and wing deformation characteristics of a flapping-wing micro air vehicle ‘DelFly II’ in hovering flight.” Bioinspiration Biomimetics 11 (3): 036014. https://doi.org/10.1088/1748-3190/11/3/036014.
Phan, H. V., and H. C. Park. 2019. “Insect-inspired, tailless, hover-capable flapping-wing robots: Recent progress, challenges, and future directions.” Prog. Aerosp. Sci. 111 (Nov): 100573. https://doi.org/10.1016/j.paerosci.2019.100573.
Sane, S. P., and M. H. Dickinson. 2002. “The aerodynamic effects of wing rotation and a revised quasi-steady model of flapping flight.” J. Exp. Biol. 205 (8): 1087–1096. https://doi.org/10.1242/jeb.205.8.1087.
Taylor, G. K., R. Nudds, and A. Thomas. 2003. “Flying and swimming animals cruise at a Strouhal number tuned for high power efficiency.” Nature 425 (6959): 707–711. https://doi.org/10.1038/nature02000.
Tobalske, B., and K. Dial. 1996. “Flight kinematics of black-billed magpies and pigeons over a wide range of speeds.” J. Exp. Biol. 199 (2): 263–280. https://doi.org/10.1242/jeb.199.2.263.
Videler, J. 2006. Avian flight. New York: Oxford University Press.
von Kármán, T. 1935. Aerodynamic theory. Berlin: Springer.
Wang, S., D. B. Ingham, L. Ma, M. Pourkashanian, and Z. Tao. 2010. “Numerical investigations on dynamic stall of low Reynolds number flow around oscillating airfoils.” Comput. Fluids 39 (9): 1529–1541. https://doi.org/10.1016/j.compfluid.2010.05.004.
Wang, S., D. B. Ingham, L. Ma, M. Pourkashanian, and Z. Tao. 2012. “Turbulence modeling of deep dynamic stall at relatively low Reynolds number.” J. Fluids Struct. 33 (Aug): 191–209. https://doi.org/10.1016/j.jfluidstructs.2012.04.011.
Weis-Fogh, T. 1973. “Quick estimates of flight fitness in hovering animals, including novel mechanisms for lift production.” J. Exp. Biol. 59 (1): 169–230. https://doi.org/10.1242/jeb.59.1.169.
Widmann, A., and C. Tropea. 2015. “Parameters influencing vortex growth and detachment on unsteady aerodynamic profiles.” J. Fluid Mech. 773 (Jun): 432–459. https://doi.org/10.1017/jfm.2015.259.
Young, J., and C. S. L. Joseph. 2007. “Mechanisms influencing the efficiency of oscillating airfoil propulsion.” AIAA J. 45 (7): 1695–1702. https://doi.org/10.2514/1.27628.
Zhang, C., and R. Claudio. 2017. “A review of compliant transmission mechanisms for bio-inspired flapping-wing micro air vehicles.” Bioinspiration Biomimetics 12 (2): 025005. https://doi.org/10.1088/1748-3190/aa58d3.
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Published In
Journal of Aerospace Engineering
Volume 35 • Issue 3 • May 2022
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© 2022 American Society of Civil Engineers.
History
Received: Feb 8, 2021
Accepted: Dec 22, 2021
Published online: Feb 24, 2022
Published in print: May 1, 2022
Discussion open until: Jul 24, 2022
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