Transactions of the Korean Society of Mechanical Engineers B (대한기계학회논문집B)

The Korean Society of Mechanical Engineers (대한기계학회)
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Aerodynamic Characteristics and Wing Tip Vortex Behavior of Three-Dimensional Symmetric Wing According to Heights

대칭단면을 갖는 3 차원 날개의 지면고도에 따른 공력특성과 끝단와 거동

  • Yoo, Younghyun (Dept. of Mechanical Engineering, Hanyang Univ.) ;
  • Lee, Sanghwan (Dept. of Mechanical Engineering, Hanyang Univ.) ;
  • Lee, Juhee (Dept. of Mechatronics Engineering, Hoseo Univ.)
  • 유영현 (한양대학교 기계공학부) ;
  • 이상환 (한양대학교 기계공학부) ;
  • 이주희 (호서대학교 메카트로닉스공학과)
  • Received : 2012.03.26
  • Accepted : 2012.09.07
  • Published : 2012.12.01
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Abstract

A numerical study has been conducted to investigate the aerodynamic characteristics and behavior of a wing-tip vortex around a three-dimensional symmetric wing (NACA0015) in the vicinity of the ground. The aerodynamic characteristics and the wing-tip vortex change as a wing approaches the ground as a result of two different phenomena: the ground effect and the Venturi effect. The ground effect increases lift and decreases drag whereas the Venturi effect generates negative lift and increases drag suddenly. A symmetric airfoil experiences both phenomena with respect to changes in the angle of attack. In the case of a NACA0015 airfoil, the Venturi effect is dominant at small angles of attack but the ground effect is dominant at large angles of attack. Interestingly, both phenomena can be observed at the 4 degree of angle of attack. The vortex core moves inside a wing when the wing experiences the Venturi effect, whereas the vortex core moves outward when the wing experiences the ground effect.

지면효과를 받는 3차원 대칭단면 날개(NACA0015)의 공력특성과 끝단와(wing-tip vortex)의 거동에 관하여 수치적 연구를 수행하였다. 날개가 지면에 근접함에 따라 공기 역학적 특성과 끝단와의 거동은 두 가지 상이한 현상(지면효과와 벤츄리효과)에 의하여 영향을 받는다. 지면효과는 양력을 증가시키며 항력을 감소시켜 공기역학적 특성을 향상시키는 반면 벤츄리효과는 음의 양력을 만들고 항력을 급격히 증가시킨다. 대칭형 익형은 받음각에 따라 이러한 현상이 모두 나타난다. NACA0015의 경우 받음각이 4도 보다 작은 경우 벤츄리효과가 지배적이며 받음각이 이 보다 큰 경우 지면효과가 지배적으로 나타난다. 특이하게 4도에서는 이 두 가지 현상이 모두 나타났다. 벤츄리효과가 지배적인 경우 지면과 날개 사이의 흡입현상의 증가로 인하여 끝단와는 날개의 안쪽으로 끌려 들어오는 반면 지면효과가 지배적인 경우 끝단와는 날개의 바깥쪽으로 밀려나가는 현상을 알 수 있었다.

Keywords

References

  1. Rozhdestvensky, K. V., 2000, Aerodynamics of a Lifting System in Extreme Ground Effect, Springer.
  2. Rozhestvensky, K. V., 2006, "Wing-in-Ground Effect Vehicles," Progress in Aerospace Sciences, Vol. 42, pp. 211-283. https://doi.org/10.1016/j.paerosci.2006.10.001
  3. Joh, C. Y. and Kim, Y. J., 2004, "Computational Aerodynamic Analysis of Airfoils for WIG(Wing-In- Ground-Effect)-Craft," Journal of the Korean Society for Aeronautical and Space Sciences, Vol. 32, No. 8, pp. 37-46. https://doi.org/10.5139/JKSAS.2004.32.8.037
  4. Han, C. H., Kim, H. K. and Cho, J. S., 2006, "Longitudinal Static Stability of Wings Flying Over Nonplanar Ground Surfaces," Journal of the Korean Society for Aeronautical and Space Sciences, Vol. 34, No. 7, pp. 12-17. https://doi.org/10.5139/JKSAS.2006.34.7.012
  5. Cho, Y. W., Cho, J. H. and Cho, J. S., 2007, "Steady Aerodynamic Characteristics of FAST Flying over Nonplanar Ground Surface," Journal of the Korean Society for Aeronautical and Space Sciences, Vol. 35, No. 6, pp. 438-488. https://doi.org/10.5139/JKSAS.2007.35.5.438
  6. Zhang, X., Toet, W. and Zerihan, J., 2006, "Ground Effect Aerodynamics of Race Cars," Applied Mechanics Reviews, Vol. 59, pp.33-49. https://doi.org/10.1115/1.2110263
  7. Katz, J., 2006, "Aerodynamics of Race Cars," Annu. Rev. Fluid Mech., Vol. 38, pp. 27-63. https://doi.org/10.1146/annurev.fluid.38.050304.092016
  8. Zhang, X. and Zerihan, J., 2004, "Edge Vortices of a Double Element Wing in Ground Effect," Journal of Aircraft, Vol. 41, No. 5, pp. 1127-1137. https://doi.org/10.2514/1.1380
  9. Jung, K.H., Chun, H.H. and Kim, H.J., 2008, Experimental Investigation of Wing-in-Ground Effect with a NACA6409 Section, Journal of Marine Science Technology, Vol. 13, pp. 317-327. https://doi.org/10.1007/s00773-008-0015-4
  10. Park, K. and Lee, J., 2008, "Influence of Endplate on Aerodynamic Characteristics of Low-Aspect-Ratio Wing in Ground Effect," Journal of Mechanical Science and Technology, Vol. 22, pp. 2578-2589. https://doi.org/10.1007/s12206-008-0805-y
  11. Lee, J., Kim, B. and Park, K., 2010, "Flow Characteristics of WIG-Effect Vehicle with Direct- Underside-Pressurization System and Propeller," Trans. of the KSME(B), Vol. 34, No. 6, pp. 649-954. https://doi.org/10.3795/KSME-B.2010.34.6.649
  12. Phillips, W. F., 2010, Mechanics of Flight, 2nd edit, John Wiley & Sons, Inc., pp. 46-49.
  13. STAR-CCM+, 2006, Methodology, CD-adapco.
  14. McAlister, K. W. and Takahashi, R. K., 1991, NACA0015 Wing Pressure and Trailing Vortex Measurements, NACA Technical Paper 3151.
  15. Jacobs, E.N. and Sherman, A., 1939, Airfoil Section Characteristics as Affected by Variations of the Reynolds Number, NACA TM. 586.
  16. Anderson, J.D., 1999, Aircraft Perfomance and Design, McGraw-Hill, pp.78-85
  17. Razenbach, R. and Barlow, J., 1994, "Two Dimensional Airfoil in Ground Effect, an Experimental and Computational Study," 1994 Motor Sports Engineering Conference, pp. 241-249.
  18. Zerihan, J. and Zhang, X., 2000, "Aerodynamics of a Single Element Wing in Ground Effect," Journal of Aircraft, Vol. 37, No. 6, pp. 1058-1064. https://doi.org/10.2514/2.2711
  19. Lee, J. H., Han, C. S. and Bae, C. H., 2010, "Influence of Wing Configurations on Aerodynamic Characteristics of Wings in Ground Effect," Journal of Aircraft, Vol. 47, No. 3, pp. 1030-1040. https://doi.org/10.2514/1.46703
  20. Zhang, J. and Zerihan, J., 2003, "Off-Surface Aerodynamic Measurements of a Wing in Ground Effect," Journal of Aircraft, Vol. 40, No. 4, pp. 716-725. https://doi.org/10.2514/2.3150