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Aerodynamics of an aerofoil in transonic ground effect: numerical study at full-scale Reynolds numbers

Published online by Cambridge University Press:  27 January 2016

G. Doig ,
T. J. Barber ,
A. J. Neely  and
D. D. Myre
G. Doig*
Affiliation:
School of Mechanical and Manufacturing Engineering, The University of New South Wales, Sydney, Australia
T. J. Barber
Affiliation:
School of Mechanical and Manufacturing Engineering, The University of New South Wales, Sydney, Australia
A. J. Neely
Affiliation:
School of Aerospace, Civil and Mechanical Engineering, The University of New South Wales at the Australian Defence Force Academy, Canberra, Australia
D. D. Myre
Affiliation:
Aerospace Engineering Department, The United States Naval Academy, Maryland, USA
*
g.doig@unsw.edu.au
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Abstract

The potential positive effects of ground proximity on the aerodynamic performance of a wing or aerofoil have long been established, but at transonic speeds the formation of shock waves between the body and the ground plane would have significant consequences. A numerical study of the aerodynamics of an RAE2822 aerofoil section in ground effect flight was conducted at freestream Mach numbers from 0·5 to 0·9, at a range of ground clearances and angles of incidence. It was found that in general the aerofoil’s lifting capability was still improved with decreasing ground clearance up until the point at which a lower surface shock wave formed (most commonly at the lowest clearances). The critical Mach number for the section was reached considerably earlier in ground effect than it would be in freestream, and the buffet boundary was therefore also reached at an earlier stage. The flowfields observed were relatively sensitive to changes in any given variable, and the lower surface shock had a destabilising effect on the pitching characteristics of the wing, indicating that sudden changes in both altitude and attitude would be experienced during sustained transonic flight close to the ground plane. Since ground proximity hastens the lower surface shock formation, no gain in aerodynamic efficiency can be gained by flying in ground effect once that shock is present.

Type
Research Article
Information
The Aeronautical Journal , Volume 116 , Issue 1178 , April 2012 , pp. 407 - 430
Copyright
Copyright © Royal Aeronautical Society 2012 

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References

1. Barber, T.J., Leonardi, E. and Archer, R.D. Causes for discrepancies in ground effect analyses, Aeronaut J, 2002, 106, (1066), pp 653–657.Google Scholar
2. Ahmed, M.R. and Sharma, S.D. An investigation on the aerodynamics of a symmetrical airfoil in ground effect, Experimental Thermal and Fluid Science, 2005, 29, pp 633–647.Google Scholar
3. Rozhdestvensky, K.V. Aerodynamics of a Lifting System in Extreme Ground Effect (text), 1st ed., Springer-Verlag, New York, USA, 2000.Google Scholar
4. Powell, J., Maise, G., Paniagua, J. and Rather, J. Maglev Launch and the Next Race to Space, IEEE Aerospace Conference Proceedings, 2008, Big Sky, USA.Google Scholar
5. Schetz, J.A. Aerodynamics of High Speed Trains, Annual Review of Fluid Mechanics, 2001, 33, pp 371–414.Google Scholar
6. Rozhdestvensky, K.V. Wing-in-ground effect vehicles, Progress in Aerospace Sciences, 2006, 42, (3), pp 211–283.Google Scholar
7. Maskalik, A.I. and Rozhdestvensky, K.V. A View of the Present State of Research in Aero-and Hydrodynamics of Ekranoplans, RTO AVT Symposium on Fluid Dynamics Problems of Vehicles Operating near or in the Air-Sea Interface, Amsterdam, The Netherlands, 5-8 October 1998.Google Scholar
8. Dragos, L. Numerical solutions of the equation for a thin airfoil in ground effect, 1990, AIAA J, 28, (12), pp 2132–2134.Google Scholar
9. Dragos, L. and Dinu, A. A direct boundary integral equations method to subsonic flow with circulation past thin airfoils in ground effect, Comput Methods Appl. Mech Eng, 1995, 121, pp 163–176.Google Scholar
10. Cook, P.H., Mcdonald, M.A. and Firmin, M.C.P. Aerofoil RAE 2822 - Pressure Distributions, and Boundary Layer and Wake Measurements. Experimental Data Base for Computer Program Assessment, 1979, AGARD Report AR 138.Google Scholar
11. Doig, G.D., Barber, T.J., Neely, A.J. and Myre, D.D. Aerodynamics of an Aerofoil in Transonic Ground Effect: Methods for Blowdown wind-tunnel Scale Testing. Submitted to the Aeronautical Journal, November 2010, revised May 2010.Google Scholar
12. Fluent User Guide, 2006,FLUENT Inc., Lebanon, NH.Google Scholar
13. Sutherland, W. The viscosity of gases and molecular force, Philosophical Magazine, 1893, 5, (36), pp 507–531.Google Scholar
14. Garbaruk, A., Shur, M., Strelets, M. and Spalart, P.R. Numerical study of wind-tunnel wall effects on transonic airfoil flow, AIAA J, 2003, 41, (6), pp 1046–1054.Google Scholar
15. Sudani, N., Sato, M., Kanda, H. and Matsuno, K. Flow visualization studies on sidewall effects in two-dimensional transonic airfoil testing, J Aircr, 1994, 31, (6), pp 1233–1239.Google Scholar
16. Spalart, P. and Allmaras, S. A one-equation turbulence model for aerodynamic flows, 1992, AIAA Paper 92-0439.Google Scholar
17. Shih, T.H., Liou, W.W., Shabbir, A., Yang, Z. and Zhu, J. A new k-ε eddy-viscosity model for high Reynolds number turbulent flows – model development and validation, 1995, Computers & Fluids, 24, (3), pp 227–238.Google Scholar
18. Menter, F.R. Two-equation eddy-viscosity turbulence models for engineering applications, AIAA J, 1994, 32, 8, pp 269–289.Google Scholar
19. Rumsey, C.L. and Vatsa, V.N. A comparison of the predictive capabilities of several turbulence models using upwind and central-difference computer codes, 1993, Proc. 31st AIAA Aerospace Sciences Meeting, Reno, USA, pp 1–16.Google Scholar
20. Szwaba, R., Doerffer, P., Namie, K. and Szulc, O. Flow structure in the region of three shock wave interaction, Aerospace Science and Technology, 2004, 8, (6), pp 499–508.Google Scholar