Hostname: page-component-848d4c4894-pjpqr Total loading time: 0 Render date: 2024-07-05T02:30:07.721Z Has data issue: false hasContentIssue false
  • English
  • Français

The air-injection method of fixing boundary-layer transition and investigating scale effects

Published online by Cambridge University Press:  04 July 2016

P. R. Ashill ,
J. L. Fulker  and
D. J. Weeks
P. R. Ashill
Affiliation:
Aerodynamics Department, RAE, Bedford
J. L. Fulker
Affiliation:
Aerodynamics Department, RAE, Bedford
D. J. Weeks
Affiliation:
Aerodynamics Department, RAE, Bedford
Get access Rights & Permissions [Opens in a new window]

Summary

The paper describes the air-injection method of fixing transition in wind-tunnel tests on a two-dimensional aerofoil and a swept panel at high subsonic free-stream speeds. The method is shown to provide a repeatable level of disturbance which, for a given flow condition, may be generated without interrupting the test and which appears not to cause a significant excess drag. Examples are given illustrating the effectiveness of the technique in demonstrating scale-sensitive features of flows, and a correlation is presented which allows the minimum value of air-injection mass flow needed to fix transition to be estimated from a knowledge of the behaviour of natural laminar flow on the wing.

Type
Research Article
Information
The Aeronautical Journal , Volume 91 , Issue 905 , May 1987 , pp. 214 - 224
Copyright
Copyright © Royal Aeronautical Society 1987 

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. Weeks, D. J. and Hodges, J. An investigation of scale effects on the transonic flow over swept wings. Part 2: Measurements on a model of a variable-sweep strike fighter configuration. RAE Technical Report 77184, 1977.Google Scholar
2. Haines, A. B., Holder, D. W. and Pearcey, H. H. Scale effects at high subsonic and transonic speeds and methods of fixing boundary-layer transition in experiments on models of aerofoils and wings. RAE Technical Note Aero 2338, 1954.Google Scholar
3. Young, A. D., Paterson, J. H. and Lloyd Jones, J. Aircraft excrescence drag. AGARD AG 264, 1981.Google Scholar
4. Winter, K. G., Scott-Wilson, J. B. and DAVIES, F. V. Methods of determination and of fixing boundary-layer transi tion on wind tunnel models at supersonic speeds. RAE Technical Note Aero 2341, 1954.Google Scholar
5. Stallings, Robert L. Junior and LAMB, Milton. Effects of roughness size on the position of boundary-layer transition and on the aerodynamic characteristics of a 55° swept delta wing at supersonic speeds. NASA TP 1027, 1977.Google Scholar
6. Nash, J. F. and Bradshaw, P. The magnification of roughness drag by pressure gradients. The Aeronautical Journal, 1967, 71, 44–46.Google Scholar
7. Pearcey, H. H. and Beavan, J. A. Profile drag measurements at compressibility speeds on aerofoils with and without spanwise wires or grooves. ARC R&M 2252, 1943.Google Scholar
8. Rogers, E. W. E. and Hall, I. M. An investigation at transonic speeds of the performance of various distributed roughness bands used to cause boundary-layer transition over the leading edge of a cropped delta half wing. With an Appendix (by Berry, C. J. and Townsend, J. F. G.) A roughness band technique and materials. NPL/Aero/377, 1959.Google Scholar
9. Wilby, P. G. and Quincey, V. G. Some effects due to different carborundum bands on the leading edges of aerofoils at high incidence in a subsonic free-stream. NPL Aero Note 1081,1969.Google Scholar
10. Fage, A. and Sargent, R. F. An air-injection method of fixing transition from laminar to turbulent flow in a boundary-layer. ARC R&M 2106, 1944.Google Scholar
11. Ashill, P. R., Fulker, J. L. and Weeks, D. J. The air-injection method of fixing boundary-layer transition and investi gating scale effects. RAE Technical Report 85025, 1985.Google Scholar
12. Thwaites, B. Approximate calculation of the laminar boundary-layer. The Aeronautical Quarterly, 1949, 1, 245.Google Scholar
13. Stewartson, K. Correlated compressible and incompressible boundary-layers. Proc. Roy. Soc. Lond. A200, 1949. 84.Google Scholar
14. Ashill, P. R. and Weeks, D. J. An experimental investigation of the drag of thick supercritical aerofoils — a progress report. RAE Technical Memorandum Aero 1765, 1978.Google Scholar
15. Collyer, M. R. and Lock, R. C. Improvements to the viscous Garabedian and Korn (VGK) method for calculating transonic flow past an aerofoil. RAE Technical Report 78039, 1978.Google Scholar
16. Ashill, P. R. RAE Report in preparation.Google Scholar
17. Cooke, J. C. Boundary layers over infinite yawed wings. The Aeronautical Quarterly, 1960, 11, 333.Google Scholar
18. Rosenhead, L. (Ed). Laminar boundary layers. Clarendon Press, Oxford.Google Scholar
19. Mabey, D. G. and Ashill, P. R. On aeroelastic oscillations associated with transitional boundary layers. RAE Technical Memorandum Aero 1995, 1984.Google Scholar
20. Smith, P. D. An integral prediction method for three- dimensional compressible turbulent boundary layers. ARC R&M 3739, 1972.Google Scholar