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Aerodynamics of an aerofoil in transonic ground effect: Methods for blowdown windtunnel scale testing

Published online by Cambridge University Press:  27 January 2016

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

Abstract

Experimental aerodynamic testing of objects in close ground proximity at high subsonic Mach numbers is difficult due to the construction of a transonic moving ground being largely unfeasible. Two simple, passive methods have been evaluated for their suitability for such testing in a small blowdown wind tunnel: an elevated ground plane, and a symmetry (or mirror-image) approach. The methods were examined using an unswept wing of RAE2822 section, with experiments and Reynolds-Averaged Navier Stokes CFD used synergistically to determine the relative merits of the techniques. The symmetry method was found to be a superior approximation of a moving ground in all cases, with mild discrepancies observed only at the lowest ground clearance. The elevated ground plane was generally found to influence the oncoming flow and distort the flowfield between the wing and ground, such that the method provided a less-satisfactory match to moving ground simulations compared to the symmetry technique.

Type
Research Article
Copyright
Copyright © Royal Aeronautical Society 2012 

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References

1. Strike, W.T. and Lucas, E.J. Evaluation of wind tunnel tests on AFMDC Monorail cone and spike nose sled configurations at Mach numbers from 2·0 to 5·0, 1968, AEDC-TR-68-198 (AD679206).Google Scholar
2. Torda, T.P. and Uzgiris, S.C. Blue flame – A land speed record vehicle, Mechanical Engineering, 1970, 92, (7), pp 918.Google Scholar
3. Goldberg, U., Akdag, V., Palaniswamy, S., Oberoi, R., Bachchan, N., Glessner, P. and Fredrick, W. CFD Analysis of the American Challenger Rocket Car, 2006, SAE 2006 World Congress & Exhibition (Vehicle Aerodynamics), pp 251258.Google Scholar
4. Weiselsberger, C. Wing resistance near the ground, 1922, NACA TM-77.Google Scholar
5. Barber, T.J., Leonardi, E. and Archer, R.D. Causes for discrepancies in ground effect analyses, Aeronaut J, 2002, 106, (1066), pp 653657.Google Scholar
6. Fink, M.P. and Lastinger, J.L. Aerodynamic characteristics of low-aspect-ratio wings in close proximity to the ground, 1961, NASA Technical Note D-926.Google Scholar
7. 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 633647.Google Scholar
8. Sowdon, A. and Hori, T. An experimental technique for accurate simulation of the flowfield for wing in surface effect craft, Aeronaut J, 1996, 100, (996), pp 215222.Google Scholar
9. Skews, B.W. Three-dimensional effects in wind tunnel studies of shock wave reflection, J Fluid Mechanics, 2003, 407, pp 85104.Google Scholar
10. Schmisseur, J.D. and Gaitonde, D.V. Numerical investigation of strong crossing shockwave/turbulent boundary-layer interactions, AIAA J, 2001, 39, (9), pp 17421749.Google Scholar
11. Doig, G., Barber, T.J., Leonardi, E., Neely, A.J. and Kleine, H. Methods for investigating supersonic ground effect in a blowdown wind tunnel, Shock Waves, 2008, 18, (2), pp 155159.Google Scholar
12. Aeschliman, D.P. and Oberkampf, W.L. Experimental methodology for computational fluid dynamics code validation, AIAA J, 1998, 36, (5), pp 733741.Google Scholar
13. Cook, P.H., McDonald, M.A. and Firmin, M.C.P. M.C.P., Aerofoil RAE 2822 – Pressure Distributions, and Boundary Layer and Wake Measurements, 1979, Experimental Data Base for Computer Program Assessment, AGARD Report AR 138.Google Scholar
14. 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 12331239.Google Scholar
15. Fluent User Guide, 2006, FLUENT Inc., Lebanon, NH.Google Scholar
16. Sutherland, W. The viscosity of gases and molecular force, Philosophical Magazine, 1893, 5, (36), pp 507531.Google Scholar
17. Spalart, P. and Allmaras, S. A one-equation turbulence model for aerodynamic flows, Recherche Aerospatiale, 1992, 1, pp 521.Google Scholar
18. Menter, F.R., Langtry, R. and Völker, S. Transition modelling for general purpose CFD codes, flow, Turbulence and Combustion, 2006, 77, (1-4), pp 277303.Google Scholar
19. Shih, T.H., Liouz, 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, Computers & Fluids, 1995, 24, (3), pp 227238.Google Scholar
20. Doig, G. Compressible Ground Effect Aerodynamics, PhD Thesis submitted to the University of New South Wales, Sydney, Australia, 2009.Google Scholar
21. 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 10461054.Google Scholar
22. Bushnell, D.M. Scaling: wind tunnel to flight, Annual Review of Fluid Mechanics, 2006, 38, pp 111128.Google Scholar