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Experimental Investigation of High-Angle-of-Attack Aerodynamics of Low-Aspect-Ratio Rectangular Wings Configured with NACA0012 Airfoil Section

  • Seok Ho Lee
  • Yong Oun HanEmail author
Original Paper
  • 4 Downloads

Abstract

To examine the high-angle-of-attack (AOA) aerodynamics, the conventional lift and drag were measured in one revolution AOA by the dynamic load cell in the wind tunnel for rectangular wings of the NACA0012 section with four different aspect ratios, 3, 4, 5, and 6, at a Reynolds number of 1.0 × 105. The results were analyzed in the normal and reverse modes of the airfoil. It was found that the reverse airfoil is disadvantageous to the lifting device because of the earlier stall than the normal and the substantial drag increases before the stall. In the entire AOA range, Prandtl’s lifting line theory seems to be applicable in general, but the profiles of the lift coefficient are not linear anymore. It was also found that the drag coefficient of the normal airfoil mode is affected by the delta wing-type vortex wrap as well as the downwash, and that the downwash effect was dominated between the deep stall and the second peak. Using the expanding scales, which have an exponential decay rate with the aspect ratio, the polar plots of the four different wings overlap in one circle with a radius of 1.0 at the same origin.

Keywords

Wind tunnel experiment High angle of attack Lift and drag coefficients Aspect ratio Polar plot 

Notes

Acknowledgements

The authors acknowledge Mr. Jae Hoon Lee for his valuable help in drawing decent graphs.

References

  1. 1.
    Laitone EV (1997) Wind tunnel tests of wings at Reynolds numbers below 70000. Exp Fluids 23(5):405–409.  https://doi.org/10.1007/s003480050128 CrossRefGoogle Scholar
  2. 2.
    Mueller TJ, Pohlen LJ, Conigliaro PE, Jansen BJ (1983) The influence of free-stream disturbances on low Reynolds number airfoil experiments. Exp Fluids 1(1):3–14.  https://doi.org/10.1007/BF00282261 CrossRefGoogle Scholar
  3. 3.
    Miley SJ (1982) Catalog of low-Reynolds-number airfoil data for wind-turbine applications (No. RFP-3387). Rockwell International Corp., Golden, CO (USA). Rocky Flats Plant; Texas A and M Univ., College Station (USA). Dept. of Aerospace EngineeringGoogle Scholar
  4. 4.
    Holst D, Church B, Pechlivanoglou G, Tüzüner E, Saverin J, Nayeri CN, Paschereit CO (2017) Experimental analysis of a NACA 0021 airfoil section through 180-degree angle of attack at low reynolds numbers for use in wind turbine analysis. In: ASME Turbo Expo 2017: turbomachinery technical conference and exposition (V009T49A006-V009T49A006). American Society of Mechanical EngineersGoogle Scholar
  5. 5.
    Bloy AW, Roberts DG (1993) Aerodynamic characteristics of the NACA 632-215 aerofoil for use in wind turbines. Wind Eng 1993:67–75Google Scholar
  6. 6.
    D’angelo S, Gili P (1988) Wind tunnel measurements of aerodynamic coefficients of asymmetrical airfoil sections for wind turbine blades, extended to high angles of attack. In: Commission of the European Communities. Contractors’ meeting, vol 2, pp 297–308Google Scholar
  7. 7.
    Rival D, Tropea C (2010) Characteristics of pitching and plunging airfoils under dynamic-stall conditions. J Aircr 47(1):80–86.  https://doi.org/10.2514/1.42528 CrossRefGoogle Scholar
  8. 8.
    Park BH, Han YO (2018) Steady aerodynamic and flow behaviors of two-dimensional NACA0012 airfoil in one revolution angle of attack. Int J Aeronaut Space Sci 119:1.  https://doi.org/10.1007/s42405-018-0010-x Google Scholar
  9. 9.
    Critzos CC, Heyson HH, Boswinkle Jr RW (1951) Aerodynamic characteristics of NACA 0012 airfoil section at angles of attack from 0 deg to 180 deg, NACA-TN-3361Google Scholar
  10. 10.
    Michos A, Bergeles G, Athanassiadis N (1983) Aerodynamic characteristics of NACA 0012 airfoil in relation to wind generators. Wind Eng 1983:247–262Google Scholar
  11. 11.
    Sheldahl RE, Klimas PC (1981) Aerodynamic characteristics of seven symmetrical airfoil sections through 180-degree angle of attack for use in aerodynamic analysis of vertical axis wind turbines (No. SAND-80-2114). Sandia National Labs., Albuquerque, NM (USA).  https://doi.org/10.2172/6548367
  12. 12.
    Massini G, Rossi E, D’angelo S (1988) Wind tunnel measurements of aerodynamic coefficients of asymmetrical airfoil sections for wind turbine blades extended to high angles of attack. In: European Community wind energy conference, pp 241–245Google Scholar
  13. 13.
    Leishman GJ (2005) Principle of helicopter aerodynamics. Cambridge University Press, CambridgeGoogle Scholar
  14. 14.
    Freymuth P, Bank W, Finaish F (1987) Further visualization of combined wing tip and starting vortex systems. AIAA J 25(9):1153–1159.  https://doi.org/10.2514/3.9760 CrossRefGoogle Scholar
  15. 15.
    Pope A, Harper JJ (1966) Low-speed wind tunnel testing, 4th edn. Wiley, New YorkGoogle Scholar
  16. 16.
    George WK, Beuther PD, Lumley JL (1978) Processing of random signals. In: Proceedings of dynamic flow conference, DenmarkGoogle Scholar
  17. 17.
    Lee JH, Han YO (2019) Numerical investigation on evolution of tip vortices generated by low-aspect ratio rectangular wings at high angle of attack. Int J Aeronaut Space Sci 20(1):1–13.  https://doi.org/10.1007/s42405-018-0101-8 MathSciNetCrossRefGoogle Scholar
  18. 18.
    Lind AH, Lefebvre JN, Jones AR (2014) Time-averaged aerodynamics of sharp and blunt trailing-edge static airfoils in reverse flow. AIAA J 52(12):2751–2764.  https://doi.org/10.2514/1.J052967 CrossRefGoogle Scholar
  19. 19.
    Ortiz X, Rival D, Wood D (2015) Forces and moments on flat plates of small aspect ratio with application to PV wind loads and small wind turbine blades. Energies 8(4):2438–2453.  https://doi.org/10.3390/en8042438 CrossRefGoogle Scholar
  20. 20.
    Prandtl L (1921) Applications of modern hydrodynamics to aeronautics. NACA TR 116Google Scholar
  21. 21.
    Abbott IH, Von Doenhoff AE (1959) Theory of wing sections. Dover Publication Inc., New York, pp 462–463Google Scholar
  22. 22.
    Anderson JD Jr (2010) Fundamentals of aerodynamics, Chapter 5, 5th edn. McGrawHill, New York, pp 440–448Google Scholar
  23. 23.
    McCormick BW (1979) Aerodynamics, aeronautics, and flight mechanics, chapter 4. Wiley, New York, p 191Google Scholar
  24. 24.
    Strickland JH (1976) Aerodynamics of the Darrieus turbine. Sandia Lab Rep 76:29–58Google Scholar

Copyright information

© The Korean Society for Aeronautical & Space Sciences 2019

Authors and Affiliations

  1. 1.School of Mechanical EngineeringYeungnam UniversityGyeongsanKorea

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