Journal of the Society of Naval Architects of Korea (대한조선학회논문집)

The Society of Naval Architects of Korea (대한조선학회)
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Numerical Simulation of Turbulent Flow around 2-D Airfoils in Ground Effect

CFD에 의한 2차원 지면 효과익 주위의 난류유동계산

  • 전호환 (부산대학교 조선해양공학과(기계기술연구소)) ;
  • 장용훈 (부산대학교 조선해양공학과) ;
  • 신명수 (한국해양연구원 해양시스템안전연구소 해양운송시스템개발본부)
  • Published : 2002.08.01
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Abstract

Turbulent flows around two-dimensional wing sections in ground effect are analysed by incompressible RANS equations and a finite difference method. The Baldwin-Lomax algebraic turbulence model is used to simulate high Reynolds number flows. The main purpose of this study is to clarify the two-dimensional ground effect and its flow characteristics due to different ground boundary conditions, i.e., moving and fixed bottom boundary. As a first step, to validate the present numerical code, the computational result of Clark-Y(t/C 11.7%) is compared with published numerical results and experimental data. Then, NACA4412 section in ground effect is calculated for various ground clearances with two bottom boundary conditions. According to the computational results, the difference in the lift and moment simulated with the two bottom boundary conditions is negligible, but the drag force simulated by the fixed bottom is to some extent smaller than that by the moving bottom. Therefore, it can be concluded that the drag force measured in a wind tunnel with the fixed bottom could be smaller than that with the moving bottom.

지면효과를 받는 2차원 날개 주위의 난류유동을 비압축성 RANS(Reynolds Averaged Navier Stokes) 방정식과 유한차분법(Finite Difference Method)을 이용하여 해석하였다. 높은 레이놀즈수에 효과적인 Baldwin-Lomax 난류모델을 사용하였다. 본 연구의 목적은 지면효과를 받는 2차원 날개단면에서의 각기 다른 두 바닥 경계조건(이동지면, 고정지면)에 따른 유동의 특성을 파악하는 것이다. Clark-Y(t/C 11.7%)날개단면의 계산 결과와 발표된 계산결과 및 실험 값과의 비교를 통해 본 수치해석 프로그램의 정확성을 검증하였다. NACA4412 날개단면에 대해 지면과의 높이변화에 대해서 두 바닥 경계조건에 대해서 유동해석을 수행하였다 계산결과에 의하면 이동지면과 고정지면에 대해서 양력과 모멘트는 별 차이가 없으나 항력은 고정지면의 경우가 이동지면의 경우보다 다소 작았다. 따라서 풍동시험에서 고정지면의 결과는 이동지면에 비해 상대적으로 저항이 낮게 평가될 가능성이 있다고 본다.

Keywords

References

  1. Akimoto, H. and Kubo, S., 1998 "Characteristics Study of Two-dimensional Wings in Surface Effect by CFD Simulations," Journal of the Society of Naval Architects of Japan, Vol.184, pp.47-54
  2. Bagley J. A., 1961 "The Pressure Distribution on Two-Dimensional Wings Near Ground", Ministry of Aviation Aeronautical Research Council R.&M. No. 3238, 40 pages
  3. Baldwin, B. S. and Lomax, H., 1978 "Thin Layer Approximation and Algebraic Model for Separated Turbulent Flows," AIAA Paper, 78-257
  4. Carr G. W. and Atkin P. D., 1997 "Influence of Moving Belt Dimensions on Vehicle Aerodynamic Forces", Proc. of Wind Tunnels and Wind Tunnel Test Techniques, Published by The Royal Aeronautical Society, London, pp.37.1 -37.16
  5. Chang R. H. 2000 "Numerical Simulation of Turbulent Flow around Two-Dimensional Wings in Ground Effect with Different Ground Boundary Condition", MSc Thesis, Dept of Naval architecture & Ocean Engineering, Pusan National University, Korea 72 p. (in korean)
  6. Chawla M. D., Edwards L. C. and Franke M. E. 1990 "Wind Tunnel Investigation of Wing - in Ground Effects", Journal of Aircraft, Vol 27, No.4, pp.289-293 https://doi.org/10.2514/3.25270
  7. Chorin A. J., 1967 "A Numerical Method for Solving Incompressible Viscous Flow Problems", Journal Computational Physics, Vol.2 No.2, pp.14-23
  8. Chun, H. H. and Chung, K. H., 1998 "A Study on the Performance of the Wing In Ground Effect by a Vortex Lattice Method", Journal of Ocean Engineering and Technology, Vol. 12, No. 2, pp. 87-96 (in Korean)
  9. Chun H. H., Chang J. H. and Paik K. J., 1999, "Longitudinal Stability of a Wing in Ground Effect Craft ", J. of The Society of Naval Architects of Korea, Vol.36, No.3, pp.60-70 (in Korean)
  10. Chun H.H., Chang C. H., Paik K. J., Shin M.S., 2000 "Wind Tunnel Test on Aerodynamic Characteristics of a PARWIG Craft", Journal of the Society of Naval Architects of Korea, Vol 37, No 3, pp.57-68 (in Korean)
  11. Hirata N., 1993 "Simulation in Viscous Flow around Two-Dimensional Power-Augmented Ram Wig in Ground Effect," Journal of the Society of Naval Architects of Japan, Vol.174, pp.47-53
  12. Hirata N., 1996 "Numerical Study on the Aerodynamic Characteristics of a Three-Dimensional Power-Augmented Ram Wing in Ground Effect," Journal of the Society of Naval Architects of Japan, Vol.179, pp.31-39.
  13. Hsiun, C. M. and Chen, A. K., 1996 "Aerodynamic Characteristics of a Two-Dimensional Arifoil with Ground Effect," Journal of Aircraft, Vol.33, No.2, pp.386-392 https://doi.org/10.2514/3.46949
  14. Jacob K., 1987 "Advance Method for Computing Flow Around Wings with Rear Separation and Ground Effect", Journal of Aircraft, Vol.24, No.2, pp.126-128 https://doi.org/10.2514/3.45429
  15. Kim H.J. and Chun H.H., 1999 “Design of 2-Dimensional WIG Section by a Nonlinear Optmization Method", Journal of the Society of Naval Architects of Korea, Vol 36, No 3, pp.50-59 (in Korean)
  16. Kim W. J., and Shin M.S. "The Effects of Mean-Line Shape on Longitudinal stability of a Wing in Ground Effect," Journal of Hydrospace Technology, Vol. 2, No.2, pp.14-23
  17. Naoki, M. and Dazuo, S., 1993 "Numerical Analysis of 3-D WIG Advancing over the Still Water Surface," Journal of the Society of Naval Architects of Japan, Vol.174, pp.35-45
  18. Nuhait A. O. and Zedan M. F., 1993 "Numerical Simulation of Unsteady Flow Induced by a Flat Plate Moving Near Ground", Journal of Aircraft, Vol.30, No. 5, pp.611-617 https://doi.org/10.2514/3.46389
  19. Park, I. R. and Chun, H. H., 1995a "A Study on Free Surface Effect of 2-D Airfoil," Journal of Ocean Engineering and Technology, Vol.9, No.2, pp. 75-82 (in Korean)
  20. Park, I. R. and Chun, H. H., 1995b "Numerical Simulation of Unsteady Performance for 2-D Surface Effect Airfoils", Journal of Ocean Engineering and Technology, Vol.9, No.2, pp. 71-74 (in Korean)
  21. Park, I. R. and Chun, H. H., 1998 "Analysis of Study and Unsteady Performance for 3-D Surface Effect Wing", Journal of the Society of Naval Architects of Korea, Vol. 35, No. 3, pp. 14-25 (in Korean)
  22. Sowdon A., 1995 " A Simple Method to Remove the Boundary Layer on a Ground Plate", Papers of Ship Research Institute (Japan), Vol.32, No.2, pp.53-78
  23. Stinton D. 1998 "The Anatomy of the Aeroplan", 2nd Edition published Blackwell Science, pp.88-92
  24. Staufenbiel, R. W., Haake, M., Kleineidam, G., Yeh, B. T., Weckesser, B., and Wessels, M., 1978 "Studies on the Flight Mechanics and Aerodynamics of Wing-In-Ground Effect Vehicles," Rheinisch-West-falische Technische Hochschule, Project Rept. 78/1, Aachen, Germany, 1978 (in German)
  25. Steinbach, D, 1996 "Comment on Aerodynamic Characteristics of a Two-Dimensional Airfoil with Ground Effect", Journal of Aircraft, Vol.34, No.3, pp.455-456 https://doi.org/10.2514/2.2195
  26. Thomas J. L., Paulson J.W. and Margason R. J., 1979 "Powered Low-Aspect-Ratio Wing in Ground Effect (WIG) Aerodynamic Characteristics ", NASA TM-78793
  27. Turner T. R., 1966 "Endless-Belt Technique for Ground Simulation ", NASA SP-116
  28. Yang, C. J. and Shin, M. S., 1998 "Numerical Simulation of 2-D Wing-In-Ground Effect," Korean Society of Computational Flows Engineering, Vol.3, No.1, pp.54-62