Aeroacoustic Simulation of an Owl Wing Cross-section Using Computational Fluid Dynamics

Year 2022, Volume: 26 Issue: 2, 375 - 387, 30.04.2022

Ferit Yıldız Sedat Tokgoz

https://doi.org/10.16984/saufenbilder.968701

Abstract

In this study, we aim to investigate the low noise flights of owls in terms of aerodynamics. The flow around cross-section of an owl wing, which is known for its nearly silent flight, is numerically analyzed using Computational Fluid Dynamics (CFD). The analysis are based on the parameters of angle of attack and the flight speed. The aerodynamic effects on the acoustic is compared in terms of vorticity and sound pressure level, where the frequency interval for the acoustic data is set to 0-7500Hz. It was seen that the vortical organisations around the airfoils are closely related to the acoustic results. The results show that the increase in both velocity and angle of attack affect the vorticity, thus lead to a rise in sound pressure level. It can be stated that the owl airfoil shape ensures a relatively silent flight.

Keywords

Aerodynamics, Airfoil, Biological Flow, Computational Fluid Dynamics

References

• [1] United States Civil Aeronautics Administration, “A Selected and Annotated Bibliography of Recent Air Age Education Textbooks,” 1947.
• [2] J. P. Fielding, Introduction to Aircraft Design. Cambridge University Press, 1999.
• [3] K. P. Valavanis and G. J. Vachtsevanos, Handbook of unmanned aerial vehicles. Springer Netherlands, 2015.
• [4] J. M. Forshaw, Encyclopaedia of Animals: Birds. Murdoch Books UK, 1991.
• [5] H. Hertel, Struktur, Form, Bewegung. Mainz: Krauskopf-Verlag, 1963.
• [6] T. Bachmann, G. Mühlenbruch, and H. Wagner, “The barn owl wing: an inspiration for silent flight in the aviation industry?,” in Bioinspiration, Biomimetics, and Bioreplication, 2011, p. 79750N.
• [7] J. del Hoyo, A. Elliott, and J. Sargatal, “Handbook of the Birds of the World. Ostrich to Ducks,” Ostrich to Ducks. 1992.
• [8] R. Sale, Falcons. Harper Collins UK, 2016.
• [9] W. Scherzinger and T. Mebs, Die Eulen Europas. Franckh-Kosmos Verlag, 2000.
• [10] H. N. Southern and H. Mikkola, “Owls of Europe,” J. Anim. Ecol., 1984.
• [11] C.-T. Edward L. and J. Roskam, Airplane Aerodynamics and Performance, 5th ed. DARcorporation, 1997.
• [12] T. Liu, K. Kuykendoll, R. Rhew, and S. Jones, “Avian wing geometry and kinematics,” AIAA J., 2006.
• [13] W. Neuhaus, H. Bretting, and B. Schweizer, “Morphologische und Funktionelle Untersuchungen Über den Lautlosen Flug Der Eulen (Strix Aluco) im Vergleich zum Flug Der Enten (Anas Platyrhynchos),” Biol. Zent. Bl., 1973.
• [14] S. Ito, “Aerodynamic influence of leading-edge serrations on an airfoil in a low Reynolds number: A study of an owl wing with leading edge serrations,” J. Biomech. Sci. Eng., 2009.
• [15] E. Mascha, “Über die Schwungfedern,” Zeitschrift für wissenschaftliche Zool., no. 77, pp. 606–651, 1904.
• [16] T. Geyer, E. Sarradj, and C. Fritzsche, “Measuring owl flight noise,” in INTERNOISE 2014 - 43rd International Congress on Noise Control Engineering: Improving the World Through Noise Control, 2014.
• [17] K. Kondo et al., “Analysis of Owl-like Airfoil Aerodynamics at Low Reynolds Number Flow,” Trans. JAPAN Soc. Aeronaut. Sp. Sci. Aerosp. Technol. JAPAN, 2014.
• [18] K. Kondo, H. Aono, T. Nonomura, A. Oyama, K. Fujii, and M. Yamamoto, “Large-eddy simulations of owl-like wing under low reynolds number conditions,” in American Society of Mechanical Engineers, Fluids Engineering Division (Publication) FEDSM, 2013.
• [19] M. Anyoji, S. Wakui, D. Hamada, and H. Aono, “Experimental Study of Owl-Like Airfoil Aerodynamics at Low Reynolds Numbers,” J. Flow Control. Meas. & Vis., 2018.
• [20] S. B. Pope, Turbulent Flows. Cambridge University Press, 2000.
• [21] T. Bensow, R. E., Fureby, C., Liefvendahl, C. & Persson, “A Comparative Study of RANS, DES and LES,” 26th ONR Symp. Nav. Hydrodyn., 2006.
• [22] A. Fluent, “Ansys Fluent Theory Guide,” ANSYS Inc., USA, 2013.
• [23] X. Liu and X. Liu, “A Numerical Study of Aerodynamic Performance and Noise of a Bionic Airfoil Based on Owl Wing,” Adv. Mech. Eng., 2014.
• [24] P. R. Spalart and S. R. Allmaras, “One-equation turbulence model for aerodynamic flows,” Rech. Aerosp., no. 1, pp. 5-21, 1994.
• [25] M. J. Lighthill, “On sound generated aerodynamically I. General theory,” Proc. R. Soc. London. Ser. A. Math. Phys. Sci., 1952.
• [26] WILLIAMS JEF and HAWKINGS DL, “Sound Generation by Turbulence and Surfaces in Arbitrary Motion,” Roy Soc London-Philosophical Trans Ser A, 1969.
• [27] M. P. Norton and D. G. Karczub, Fundamentals of Noise and Vibration Analysis for Engineers. 2003.
• [28] G. Tucker, V.; Parrot, “Aerodynamics of Gliding Flight in a Falcon and Other Birds,” J. Exp. Biol., 1970. [29] T. Wolf and R. Konrath, “Avian wing geometry and kinematics of a free-flying barn owl in flapping flight,” Exp. Fluids, 2015.
• [30] T. Geyer, E. Sarradj, and C. Fritzsche, “Silent owl flight: Comparative acoustic wind tunnel measurements on prepared wings,” Acta Acust. united with Acust., 2013.
• [31] E. Sarradj, C. Fritzsche, T. Geyer, and E. Gutmark, “Silent OWL flight: Bird flyover noise measurements,” AIAA J., 2011.
• [32] J. Kopania, “Acoustics Parameters the Wings of Various Species of Owls,” Inter-Noise Noise-Con Congr. Conf. Proc., pp. 6841–7829, 2016. [33] T. Geyer, E. Sarradj, and C. Fritzsche, “Measurement of the noise generation at the trailing edge of porous airfoils,” Exp. Fluids, 2010.
• [34] J. Vad, G. Koscsó, M. Gutermuth, Z. Kasza, T. Tábi, and T. Csörgo, “Study of the aero-acoustic and aerodynamic effects of soft coating upon airfoil,” JSME Int. Journal, Ser. C Mech. Syst. Mach. Elem. Manuf., 2007.
• [35] D. Li and X. Liu, “Aerodynamic performance and acoustic characteristics of bionic airfoil inspired by three-dimensional long-eared owl wing under low reynolds number,” in Proceedings of the ASME Turbo Expo, 2016.
• [36] H. Roeser, R. J.; Valente, Michael ; Hosford-Dunn, Audiology Diagnosis, 2nd ed. Thieme, 2007.