Hostname: page-component-cd9895bd7-q99xh Total loading time: 0 Render date: 2024-12-28T04:41:02.538Z Has data issue: false hasContentIssue false

The onset of compressibility effects for aerofoils in ground effect

Published online by Cambridge University Press:  03 February 2016

G. Doig
Affiliation:
School of Mechanical and Manufacturing Engineering, University of New South Wales, Sydney, Australia
T. J. Barber
Affiliation:
School of Mechanical and Manufacturing Engineering, University of New South Wales, Sydney, Australia
E. Leonardi
Affiliation:
School of Mechanical and Manufacturing Engineering, University of New South Wales, Sydney, Australia
A. J. Neely
Affiliation:
School of Aerospace, Civil and Mechanical Engineering, University of New South Wales at the Australian Defence Force Academy, Canberra, Australia

Abstract

The influence of flow compressibility on a highly-cambered inverted aerofoil in ground effect is presented, based on two-dimensional computational studies. This type of problem has relevance to open-wheel racing cars, where local regions of high-speed subsonic flow form under favourable pressure gradients, even though the maximum freestream Mach number is typically considerably less than Mach 0·3. An important consideration for CFD users in this field is addressed in this paper: the freestream Mach number at which flow compressibility significantly affects aerodynamic performance. More broadly, for aerodynamicists, the consequences of this are also considered. Comparisons between incompressible and compressible CFD simulations are used to identify important changes to the flow characteristics caused by density changes, highlighting the inappropriateness of incompressible simulations of ground effect flows for freestream Mach numbers as low as 0·15.

Type
Technical note
Copyright
Copyright © Royal Aeronautical Society 2007 

Access options

Get access to the full version of this content by using one of the access options below. (Log in options will check for institutional or personal access. Content may require purchase if you do not have access.)

References

1. Zhang, X., Toet, W. and Zerihan, J.. Ground effect aerodynamics of race cars, Applied Mech Reviews, 2006, 59, pp 3349.Google Scholar
2. Kim, C.S., Chongam, K. and Rho, O.H., Computations of high-lift aerofoil flows using two-equation turbulence models AIAA 99-0542.Google Scholar
3. Katz, J.. Aerodynamics of race cars, Annual Review of Fluid Mech, 2006, 38, pp 2763.Google Scholar
4. Katz, J., Calculation of the aerodynamic forces on automotive lifting surfaces, ASME J Fluids Eng, 1985, 107, pp 438443.Google Scholar
5. Ranzenbach, R. and Barlow, J., Two-dimensional aerofoil in ground effect, an experimental and computational study, 1994, SAE Paper 94-2509.Google Scholar
6. Ranzenbach, R. and Barlow, J., Cambered aerofoil in ground effect: an experimental and computational study, 1996, SAE Paper 96-0909.Google Scholar
7. Zerihan, J. and Zhang, X.. Aerodynamics of a single element wing in ground effect, J Aircr, 2000, 37, (6), pp 10581064.Google Scholar
8. Zerihan, J. and Zhang, X.. Aerodynamics of a double element wing in ground effect, AIAA J, 2003, 41, (6), pp 10071016.Google Scholar
9. Mahon, S. and Zhang, Z.. Computational analysis of pressure and wake characteristics of an aerofoil in ground effect, J Fluids Eng, 2005, 127, pp 290298.Google Scholar
10. Mahon, S. and Zhang, Z.. Computational analysis of a inverted double-element aerofoil in ground effect, J Fluids Eng, 2006, 128, pp 11721180.Google Scholar
11. Zerihan, J. and Zhang, X., A single element wing in ground effect; comparisons of experiments and computation, 2001, AIAA Paper 2001-0423.Google Scholar
12. Roller, S. and Munz, C.D.. A low Mach number scheme based on multi-scale asymptotics, Computing and Visualization in Science, 2000, 3, (1/2), pp 8591.Google Scholar
13. Keshtiban, I.J., Belblidia, F. and Webster, M.F., Compressible flow solvers for low Mach number flows — a review, 2004, University of Wales Computer Science Report CSR-2004.Google Scholar
14. Zerihan, J., An Investigation into the Aerodynamics of Wings in Ground Effect, 2001, PhD thesis, University of Southampton, School of Engineering Sciences.Google Scholar
15. 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
16. Roache, P.J.. Quantification of uncertainty in computational fluid dynamics, Annual Review of Fluid Mech, 1997, 29, pp 123160.Google Scholar
17. Shih, T.H., Liou, W.W., Shabbir, A., Yang, Z. and Zhu, J.. A new k-ω eddy-viscosity model for high Reynolds number turbulent flows — model development and validation, Computers & Fluids, 1995, 24, (3), pp 227238.Google Scholar
18. Kader, B., Temperature and concentration profiles in fully turbulent boundary layers, Int J Heat Mass Transfer, 1981, 24, (9), pp 15411544.Google Scholar
19. Liou, W.W., Huang, G. and Shih, T.H.. Turbulence model assessment for shock wave/turbulent boundary-layer interaction in transonic and supersonic flows, Computers and Fluids, 2000, 29, pp 275299.Google Scholar
20. Gonclaves, E. and Houdeville, R.. Turbulence model and numerical scheme assessment for buffet computations, Int J for Numerical Methods in Fluids, 2004, 46, pp 11271152.Google Scholar
21. Menter, F.R.. Two-equation eddy-viscosity turbulence models for engineering applications, AIAA J, 1994, 32, (8), pp 15981605.Google Scholar
22. Spalart, P. and Allmaras, S., A one-equation turbulence model for aerodynamic flows, 1992, AIAA Paper 92-0439.Google Scholar
23. Brunet, V.. Computational study of buffet phenomenon with unsteady RANS equations, 2003, 21st AIAA Applied Aerodynamics Conference, AIAA Paper 2003-3679.Google Scholar
24. Xiao, Q., Tsai, H.M. and Liu, F.. Numerical study of transonic buffet on a supercritical aerofoil, AIAA J, 2006, 44, (3), pp 620628.Google Scholar
25. Deck, S.. Numerical simulation of transonic buffet over a supercritical aerofoil, AIAA J, 2005, 43, (7), pp 15561566.Google Scholar
26. Lee, B.H.K.. Transonic buffet on a supercritical aerofoil, Aeronaut J 1990, 94, (935), pp 143152.Google Scholar
27. Lee, B.H.K.. Oscillation shock motion caused by transonic shock boundary layer interaction, AIAA J, 1990, 28, (5), pp 942944.Google Scholar
28. Lee, B.H.K.. Self-sustained shock oscillations on aerofoils at transonic speeds, Prog in Aerospace Sci, 2001, 37, pp 147196.Google Scholar
29. Fackrell, J.E., The Aerodynamics of an Isolated Wheel Rotating in Contact with the Ground, 1974, PhD thesis, University of London.Google Scholar