Hostname: page-component-78c5997874-8bhkd Total loading time: 0 Render date: 2024-11-08T04:50:04.596Z Has data issue: false hasContentIssue false
  • English
  • Français

Design of Supercritical Aerofoils

Published online by Cambridge University Press:  07 June 2016

R C Lock  and
J L Fulker
R C Lock
Affiliation:
Royal Aircraft Establishment, Farnborough
J L Fulker
Affiliation:
Royal Aircraft Establishment, Farnborough
Get access

Summary

A survey is given of experimental results on a series of aerofoils designed in recent years, first at the National Physical Laboratory and later at the Royal Aircraft Establishment, with the intention of operating at relatively high subsonic Mach numbers (around 0.8) with, on the upper surface, a large extent of supercritical flow, terminated by a weak shock wave. The paper describes the design of a basic aerofoil, together with some modifications to it which were successful in improving its performance at both high and low speeds. It is shown that the best of these aerofoils, with thickness/chord ratio 0.105, has a drag rise Mach number of 0.80 at a lift coefficient of 0.5, thus comparing favourably in this respect with other published examples; its maximum lift coefficient at low speeds, 1.2, is also satisfactory for an aerofoil of this thickness. In a final section some comparisons are given between these experimental results and some theoretical calculations by the finite-difference method of Garabedian and Korn, including a partial allowance for viscous effects. It is concluded that, although reasonable overall agreement with experiment is often obtained, further improvements in this theory are needed before it can be used with confidence for practical purposes.

Type
Research Article
Information
Aeronautical Quarterly , Volume 25 , Issue 4 , November 1974 , pp. 245 - 265
Copyright
Copyright © Royal Aeronautical Society. 1974

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 Pearcey, H H, Aerodynamic design of section shapes for swept wings. Advances in Aeronautical Sciences, Vol 3, pp 277–323, Pergamon Press, 1962.Google Scholar
2 Pearcey, H H, NPL Annual Report for 1963 (Aerodynamics Division), HMSO, 1964.Google Scholar
3 Nieuwland, G Y, Spee, B M, Transonic shock free flow – fact or fiction? AGARD Conference Proceedings 35, Paper 1, 1968.Google Scholar
4 Stratford, B S, The prediction of separation of the turbulent boundary layer. Journal of Fluid Mechanics, Vol 5, Part 1, 1959.Google Scholar
5 Stratford, B S, Drag-rise Mach number of aerofoils having a specified form of upper-surface pressure distribution. Charts and comments on design. ESDU Item 71019 (Appendix B), 1971.Google Scholar
6 Hall, D J, Quincey, V G, Lock, R C, Some results of wind tunnel tests on an aerofoil section (NPL 9510) combining a “peaky” upper-surface pressure distribution with rear loading. ARC Current Paper 1292, 1974.Google Scholar
7 Hall, D J, Quincey, V G, Macdonald, A G J, A brief description of some characteristics of aerofoil section NPL 9515, a development of NPL 9510. NPL, unpublished, 1970.Google Scholar
8 Lock, R C, Powell, B J, Sells, C C L, Wilby, P G, The prediction of aerofoil pressure distributions for subcritical viscous flows. AGARD Conference Proceedings 35, Paper 13, 1968.Google Scholar
9 Goodmanson, L T, Transonic transports. Proceedings, 12th Anglo-American Aeronautical Conference, Calgary, 1971.Google Scholar
10 Bauer, F, Garabedian, P R, Korn, D, Supercritical wing sections. Lecture notes in Economics and Math Systems 66. Springer-Verlag, Berlin, 1972.Google Scholar
11 Moss, G F, Haines, A B, Jordan, R, The effect of leading edge geometry on high-speed stalling. RAE Technical Report 72099, 1972.Google Scholar
12 Sells, C C L, Plane subcritical flow past a lifting aerofoil. Proc Roy Soc A, Vol 308, pp 377–401, 1968.Google Scholar
13 Murman, E M, Cole, J D, Calculation of plane steady transonic flow. Boeing Scientific Research Laboratories, Paper DI-82-0943, 1970.Google Scholar
14 Green, J E, Weeks, D J, Brooman, J W F, Prediction of turbulent boundary layers and wakes in compressible flow by a lag-entrainment method. RAE Technical Report 72231, 1972.Google Scholar
15 Lock, R C, Test cases for numerical methods in two-dimensional transonic flows. AGARD Report 575-70, 1970.Google Scholar
16 Jones, A F, Firmin, M C P, On the calculation of viscous effects on the supercritical flow over an aerofoil. RAE Technical Report 72233, 1972.Google Scholar
17 Firmin, M C P, The calculation of pressure distributions, lift and drag on single aerofoils at subcritical speeds. RAE Technical Report 72235, 1972.Google Scholar
18 Hall, D J, Love, E M, The design of two supercritical aerofoils derived from the NPL 95- series. RAE, unpublished, 1971.Google Scholar