Hostname: page-component-cd9895bd7-dk4vv Total loading time: 0 Render date: 2024-12-27T08:12:24.492Z Has data issue: false hasContentIssue false

Performance of improved thin aerofoil theory for modern aerofoil sections

Published online by Cambridge University Press:  04 July 2016

K. Abu-Abdou
Affiliation:
Mechanical Engineering Department , King Saud University Riyadh, Saudi Arabia
M. F. Zedan
Affiliation:
Mechanical Engineering Department , King Saud University Riyadh, Saudi Arabia

Abstract

The improved thin aerofoil method, which features extended expressions for lift and moment coefficients, is considered for further investigation and validation. The procedure to calculate the singularity coefficients is improved by using all aerofoil coordinates as control points in a least squares scheme. The classical NACA 0012 and NACA 65012 sections, the modern aviation aerofoil LS(1)—0417 and the extremely thick Kennedy-Marsden aerofoil are validated in place of the previously cited Karman-Trefftz aerofoil. This selection covers thickness ratios of up to 27·9%, camber ratios up to 7·69% and incidence up to 16·7°. Comparisons of velocity (or pressure) distributions and aerodynamic coefficients are made with two panel methods and with exact solution or experimental results whichever is available. Results indicated that the accuracy of the extended method is much better than expected and compares well with panel methods except for the extremely thick aerofoil. Additional results in the form of a systematic investigation of a weighted global error in the pressure distribution for the Karman-Trefftz aerofoils used in the previous study, are also included. Such an error shows similar trends and in many cases comparable magnitude to the errors generated by panel methods.

Type
Research Article
Copyright
Copyright © Royal Aeronautical Society 1991 

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. Zedan, M. F. and Abu-Abdou, K. Improved thin-airfoil theory, J Aircr, Dec 1988, 25, (12), pp 11221128.Google Scholar
2. Moran, J. Panel method. An Introduction to Theoretical and Computational Aerodynamics, Wiley, New York, 1984, pp 260287.Google Scholar
3. Plotkin, A.Technical Comment on ‘Improved thin-airfoil theory’, JAircr, May 1990, 27, (5), pp 478479.Google Scholar
4. van dyke, M. D. Second-Order Subsonic Airfoil Theory Including Edge Effects, NACA Report 1274, 1956, pp 541560.Google Scholar
5. Keuthe, A. and Chow, C.-Y. The Airfoil of Arbitrary Thickness and Camber, in: Foundation of Aerodynamics, Wiley & Sons, New York, 1986, pp 128137.Google Scholar
6. Duncan, W. J., Thom, A. S. and Young, A. D. Two-dimensional flow, in: Mechanics of Fluids, 2nd ed., E. Arnold, Surrey, 1978, pp 578579.Google Scholar
7. Csanday, G. T. Thin-airfoil theory, in: Theory of Turbomachines, McGraw Hill, N.Y., 1964, pp 196222.Google Scholar
8. Kennedy, J. L. and Marsden, D. J. The development of high lift, single-component airfoil sections, Aeronaut Q, Feb 1979,30, pp 343359.Google Scholar
9. Abbot, I. H. and von doenhoff, A. G. Theory of Wing Sections, Dover, New York, 1959.Google Scholar
10. Anderson, J. D. Incompressible flow over airfoils, in: Fundamentals of Aerodynamics, McGraw Hill, Singapore, 1985, pp 86226.Google Scholar
11. Dutt, H. N. V.Comment on ‘Computation of the potential flow over airfoils with cusped or thin trailing edges’, AIAA J, Jan 1988, 26, (l), pp 122123.Google Scholar
12. Catherall, D., Foster, D. N. and Sells, C. C. L. TWO Dimensional Incompressible Flow Past a Lifting Airfoil. RAE Tech. Report. 69118, 1969.Google Scholar
13. Mcghee, R. J. and Beasley, W. D. LOW Speed Aerodynamic Characteristics of a 17%-Thick Airfoil Section Designed for Aviation Applications, NASA TN D-7428, Dec 1973.Google Scholar
14. Mcghee, R. J., Beasley, W. D. and Whitcomb, R. T. NASA Low and Medium-Speed Airfoil Development, NASA Tech. Memorandum 78709, 1979.Google Scholar
15. Kennedy, J. L. and Marsden, D. J. A potential flow design method for multicomponent airfoil sections, J Aircr, 1978, 15, (1), pp 4752.Google Scholar