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Scale effects on a single-element inverted wing in ground effect

  • J. Correia, L. S. Roberts (a1), M. V. Finnis (a1) and K. Knowles (a1)


A study was conducted on a GA(W)-1 wing in order to investigate the effect of testing inverted wings in ground effect at low Reynolds numbers. The wing was tested at a range of ground clearances and Reynolds numbers and results showed that the wing’s performance was dependent on both these parameters. Surface flow-visualisation and numerical simulation results highlighted the existence of a laminar separation bubble on the wing’s suction surface. The results also indicated that both the bubble’s length and the onset of separation were sensitive to ground clearance and Reynolds number. Attempts were made to minimise the wing’s Reynolds number dependency by using transition strips on the suction surface. The transition strip results highlighted the influence that a laminar separation bubble has on the overall performance of the wing and how its presence alters the force enhancement and reduction mechanisms on an inverted wing in ground effect.


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1. Mabey, D.G. A review of scale effects in unsteady aerodynamics, Prog Aerospace Sci, 1991, 28, pp 273321.
2. Braslow, A. and Knox, E. Simplified method for determination of critical height of distributed roughness particles for boundary-layer transition at Mach numbers from 0 to 5, Technical Note 4363, NACA, Langley Aeronautical Laboratory, 1958.
3. Tani, I. Low-speed flow involving bubble separations, Progress in Aeronautical Sciences, 1964, 5, pp 70103.
4. Liebeck, R. and Blackwelder, R. Low Reynolds number – separation bubble, University of Southern California, Final Technical Report for contract N00014-84-K-0500 (Available from Defense Technical Information Center as AD-A199 378), 1987.
5. Mueller, T.J. and Batill, S.M. Experimental studies of separation on a two-dimensional airfoil at low Reynolds numbers, AIAA J, 1982, 20, (4), pp 457463.
6. Genc, M.S., Karasu, I. and Acikel, H.H. An experimental study on the aerodynamics of NACA2415 aerofoil at low Re numbers, Experimental Thermal and Fluid Sciences, 2012, 39, pp 252264.
7. Diwan, S. and Ramesh, O.N. Laminar separation bubbles: dynamics and control, Sadhana – Indian Academy of Sciences Proceedings in Engineering Sciences, 2007, 32, Part 1 and 2, pp 103109.
8. Zerihan, J. and Zhang, X. Aerodynamics of a single element wing in ground effect, 38th AIAA Aerospace Sciences Meeting and Exhibit, Reno, NV, USA. AIAA Paper 2000-0650, AIAA, 2000.
9. Knowles, K., Donoghue, D.T. and Finnis, M.V. A study of wings in ground effect. Proc. RAeS Conference on Vehicle Aerodynamics, Loughborough, UK, 1994, pp 22.1–22.13.
10. Ranzenbach, R. and Barlow, J.B. Two-dimensional airfoil in ground effect, an experimental and computational study, Motorsports Engineering Conference and Exposition, Dearborn, MI, USA, SAE Paper 942509, 1994.
11. Ranzenbach, R. and Barlow, J.B. Cambered airfoil in ground effect- wind tunnel and road conditions, AIAA 13th Applied Aerodynamics Conference, San Diego, CA, USA, AIAA Paper 95-1909, 1995.
12. Ranzenbach, R. and Barlow, J. Cambered airfoil in ground effect – an experimental and computational study. In International Congress and Exposition, Vehicle Aerodynamics: Wind Tunnel, CFD, Aeroacoustics, and Ground Transportation Systems, Detroit, MI, USA, SAE Paper 960909, 1996.
13. Jasinski, W. and Selig, M. Experimental study of open-wheel race-car front wings, Motorsports Engineering Conference and Exposition, Dearborn, MI, USA, SAE Paper 983042, 1998.
14. Zerihan, J. and Zhang, X. A single element wing in ground effect; comparisons of experiments and computation, In 39th AIAA Aerospace Sciences Meeting and Exhibit, Reno, NV, USA, AIAA Paper 2001-0423, 2001.
15. Zhang, X., Zerihan, J., Ruhrmann, A. and Deviese, M. Tip vortices generated by a wing in ground effect, In 11th International Symposium on Applications of Laser Techniques to Fluid Mechanics, Lisbon, Portugal, IST, 2002.
16. Molina, J. and Zhang, X. Aerodynamics of oscillating wings in ground effect, 48th AIAA Aerospace Sciences Meeting including the New Horizons Forum and Aerospace Exposition, Orlando, FL, USA. AIAA Paper 2010-318, 2010.
17. Beves, C.C., Barber, T.J. and Leonardi, E. Airfoil flow separation suppression using dimples, The Aeronaut J, 2011, 115, (1168), pp 335344.
18. Knowles, K. and Finnis, M.V. Development of a new open-jet wind tunnel and rolling road facility, in 2nd MIRA International Conference on Vehicle Aerodynamics, Coventry, UK, 20-21 October 1998.
19. von Doenhoff, A.E. and Horton, E.A. A low-speed experimental investigation of the effect of a sandpaper type of roughness on boundary-layer transition, NACA Rep 1349, 1958.
20. van Ingen, J.L. A suggested semi-empirical method for the calculation of boundary layer transition region, Report Nos. V.T.H-71, Report V.T.H.-74 (in English), Delft, The Netherlands, 1956.
21. Smith, A.M.O. and Gamberoni, N. Transition, pressure gradient and stability theory, Proc. 9th Int. Congr. Appl. Mech, John Wiley and Sons, Chichester, UK, 1956.
22. White, F.M. Viscous Fluid Flow, New York, USA, McGraw-Hill, 1974.


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