Volume – 2 Issue – 1 Article – 3

A Study on Aerodynamic Behavior of Subsonic UAVs' Wing Sections with Flaps

Halil Yalçın Akdeniz
Eskisehir Osmangazi University, Eskisehir Vocational School, Odunpazarı, Eskisehir
F IJAST 2021; 2 (1) : DOI: 10.23890/IJAST.vm02is01.0203; Language: EN

This study, it is aimed to assess the aerodynamic and flight effects of the flap design on an airfoil. For this purpose, the NACA 4415 type wing profile, which can also be used in unmanned aerial vehicles (UAVs), is selected. The original design and the +5-degree flapped design which has constant other design features, are compared. Assessments are performed under constant Reynolds numbers and an angle of attack between 0-10 degrees with a 1-degree interval.
Analyses are made using the open-source software XFLR5. For the flapped design is named NACA 4415-2, some basic aerodynamic performance parameters such as coefficient of drag (CD), coefficient of lift (CL), coefficient of pressure (Cp), maximum lift coefficient (Clmax) and minimum stall velocity (Vstall) have been observed. According to results, when the flap with 5o is added to the airfoil, it has been observed that the CL and Lift force of the original design of the airfoil increase significantly, CD of the airfoil increase partially. The pressure coefficient tends to decrease significantly. Furthermore, it has been observed that while the minimum stall velocity has decreased, Clmax values increased.

Aerodynamic Performance
Wing Design
NACA 4415

  1. Akdeniz, H.Y., 2020, Performance Analysis of a Wing Used in Unmanned Systems, International Symposium on Electric Aviation and Autonomous Systems – International Symposium on Aircraft Technology, MRO and Operations Proceedings, 2020: Kyiv, Ukraine.
  2. Alam, G.J. and Mamun, M., 2021, February. Aerodynamic Characteristics of Aerofoil Shaped Fuselage UAV Model and Compare With the Conventional Model Using CFD Software. In AIP Conference Proceedings (Vol. 2324, No. 1, p. 040001). AIP Publishing LLC.
  3. Arunvinthan, S. and Pillai, S.N., 2019, Aerodynamic characteristics of unsymmetrical aerofoil at various turbulence intensities. Chinese Journal of Aeronautics, 32(11), pp.2395-2407.
  4. Chen, J., Wang, Q. and Sun, Z. eds., 2017, Wind turbine airfoils and blades: Optimization design theory. China Science Publishing & Media Lt, De Gruyter.
  5. Chervonenko, A.G., Kaminer, A.A., Berne, A.L. and Chuprun, O.B., 1993, effect of attack angle on the non-stationary aerodynamic characteristics and flutter resistance of a grid of bent vibrating compressor blades. Strength of materials, 25(10), pp.768-771.
  6. Drela, M., 1986, Two-dimensional transonic aerodynamic design and analysis using the Euler equations. Cambridge, Mass.: Gas Turbine Laboratory, Massachusetts Institute of Technology.
  7. FAS, 2021a, Next Generation Air Transportation System Unmanned Aircraft Systems Research, Development and Demonstration Roadmap, available at: https://fas.org/irp/program/collect/uasnextgen.pdf (accessed 16 May 2021)
  8. FAS, 2021b, Unmanned Aircraft Systems Roadmap 2005 – 2030, https://fas.org/irp/program/collect/uav_roadmap2005.pdf Access Date: 16.05.2021
  9. Gupta, S.G., Ghonge, M.M. and Jawandhiya, P.M., 2013, Review of unmanned aircraft system (UAS). International journal of advanced research in computer engineering & technology (IJARCET), 2(4), pp.1646-1658.
  10. Phillips, H.F., 2004, Flying Wings – Aviation and Aeromodelling – Interdependent Evolutions and Histories, Http://Www.Ctie.Monash.Edu.Au/Hargrave/Phillips.Html. HF,
  11. Xu, 1979, Fundamentals of Aerodynamics. Peking: National Defense of Industry Press
  12. Joseph Daniel, S., 2020, Performance Analysis of Asymmetrical airfoil for Subsonic flight using XFLR5 software, The International Journal of Progressive Research in Science and Engineering, 1(8), pp.8-11.
  13. Kadvea, A., Sharmab, P., Patelc, A., 2016, Review on CFD analysis on aerodynamic design optimization of wind turbine rotor blade, International Journal of Innovative and Emerging Research in Engineering, 3(5), pp.178-182.
  14. Kanimozhi, G. V., 2018, Analysis of Airfoil Flow Pattern using CFD., in: International Journal of Engineering Research & Technology (IJERT) Confcall – 2018 Conference Proceedings. ISSN: 2278-0181 Published by, www.ijert.org
  15. Nonami, K., Kendoul, F., Suzuki, S., Wang, W. and Nakazawa, D., 2010, Autonomous flying robots: unmanned aerial vehicles and micro aerial vehicles. Springer Science & Business Media.
  16. Qian, YJ., 2005, Aerodynamics. Beijing University of Aeronautics and Astronautics Press, Peking.
  17. Quintana, E., 2008, The ethics and legal implications of military unmanned vehicles. RUSI, Occasional Paper.
  18. Raymer, D., 2018, Aircraft Design: A Conceptual Approach, Sixth Edition. American Institute of Aeronautics and Astronautics, Inc., Washington, DC
  19. Rubel, R.I., Uddin, M.K., Islam, M.Z. and Rokunuzzaman, M.D., 2016, Numerical and experimental investigation of aerodynamics characteristics of NACA 0015 aerofoil. International Journal of Engineering Technologies, 2(4), pp.132-141.
  20. Khan, S., Ilkal, S. H., Rekha, R., 2019, Design of High Lift Low Reynolds Number Airfoil for Micro Aerial Vehicle, International Journal of Innovative Science and Research Technology, 4(3), pp.186-192.
  21. Seli̇m, S., Akşar, E., 2018, Sabit Kanatli İnsansiz Hava Araçlarinda (İHA) Kanat Tasariminin Uçuş Süresi, Manevra Kabiliyeti ve Kalkiş Hizi (vstall) Üzerine Etkilerinin Araştirilmasi, in Uzaktan algilama ve cbs sempozyumu uzal-cbs 2018: Eskişehir Teknik Üniversitesi.
  22. Srinivasan, G.R., Ekaterinaris, J.A. and McCroskey, W.J., 1995, Evaluation of turbulence models for unsteady flows of an oscillating airfoil. Computers & Fluids, 24(7), pp.833-861.
  23. UIUC Aerofoil Coordinates Database, 2010, available at:
    https://mselig.ae.illinois.edu/ads/coord_database.html (accessed 2020)
  24. Vogeltanz, T., 2016, A survey of free software for the design, analysis, modelling, and simulation of an unmanned aerial vehicle. Archives of Computational Methods in Engineering, 23(3), pp.449-514.
  25. XFLR5, 2020, available at: http://www.xflr5.com/xflr5.html (accessed 29 July 2020)
  26. Yan, Y., Avital, E., Williams, J. and Cui, J., 2020, Performance improvements for a vertical axis wind turbine by means of Gurney flap. Journal of Fluids Engineering, 142(2).
  27. Yi, Z., Wu, X. and Zhou, LZ., 2005, Low Speed Aerodynamics. Press of Metallurgy Industry, Peking.
  28. Yiğit, E., Yazar, I. and Karakoç, H.T., 2018, İnsansız Hava Araçları (İHA)’nın Kapsamlı Sınıflandırması ve Gelecek Perspektifi. Sürdürülebilir Havacılık Araştırmaları Dergisi, 3(1), pp.10-19.
  29. Yilmaz, I. 2018, available at: https://uavturkey.tubitak.gov.tr/assets/2018_iha_egitim_ilker_yilmaz.pdf (accessed 17 April 2020)
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