Hostname: page-component-78c5997874-j824f Total loading time: 0 Render date: 2024-11-06T10:46:25.500Z Has data issue: false hasContentIssue false

A guide to classical flutter

Published online by Cambridge University Press:  04 July 2016

L. T. Niblett*
Affiliation:
Materials and Structures Department Royal Aerospace Establishment, Farnborough

Summary

First essentials of classical flutter are demonstrated by a comprehensive study of the behaviour of a lifting surface with two degrees of freedom under the action of airforces limited to those in phase with displacement. Structural coupling between the coordinates is eliminated by taking the normal modes to be the deflection coordinates, and this results in conditions for stability with particularly concise forms. It is shown that the flutter stability can be seen to be very much a matter of the relative amplitudes of heave and pitch in the normal modes.

In-quadrature airforces are then introduced and it is shown that they have little effect when the flutter is severe. They are of more importance in the milder forms of flutter, the extreme of which are shown to be little different from instabilities in a single degree of freedom.

Type
Research Article
Copyright
Copyright © Royal Aeronautical Society 1988 

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.)

Footnotes

*

Now retired.

References

1. Von Karman, T. and Biot, M. A. Mathematical Methods in Engineering, McGraw-Hill, 1940, 220228.Google Scholar
2. Niblett, LI. T. A graphical representation of the binary flutter equations in normal coordinates, ARC R&M3496, 1966.Google Scholar
3. Pines, S. An elementary explanation of the flutter mechanism. In: Proceedings of IAS National Specialists Meeting on Dynamics and Aeroelasticity, Fort Worth, 1958, 5258.Google Scholar
4. Zimmerman, N. H. Elementary static aerodynamics add significance and scope in flutter analyses. In: Proceedings of A1AA Symposium on Structural Dynamics of High Speed Flight, 1961, 2884.Google Scholar
5. Duncan, W. J. The fundamentals of flutter, ARC R&M2417, 1948.Google Scholar
6. Duncan, W. J. Flutter and stability, J R Aeronaut Soc, 1949, 529549.Google Scholar
7. Niblett, LI. T. The flutter of a two-dimensional wing with simple aerodynamics, ARC CP1355, 1975.Google Scholar
8. Da Vies, R. J. The form of the complementary function of a binary aeroelastic system at frequency coalescence, RAE Technical Report 72024, 1972.Google Scholar
9. Frazer, R. A. and Duncan, W. J. The flutter of aeroplane wings, ARC R&M1155, 1928.Google Scholar
10. Collar, A. R. Broadbent, E. G. and Puttick, E. B. An elaboration of the criterion for wing torsional stiffness, ARC R&M2154, 1946.Google Scholar
11. Küssner, H. G. Schwingungen von Flugzeugflugeln, Luftfahrt-forschung, 1929, 4, 41.Google Scholar
12. Garrick, I. E. and Reed, W. H. III Historical development of aircraft flutter, J Aircr, 1981, 18, 897912.Google Scholar
13. Jordan, P. F. Aerodynamic flutter coefficients for subsonic, sonic and supersonic flow (linear two-dimensional theory), ARC R&M2932, 1953.Google Scholar
14. Reed, W. H. III, Foughner, J. T. Jr. and Runyan, H. L. Jr. Decoupler pylon: a simple, effective wing/store flutter suppressor, J Aircr, 1980, 17, 206211.Google Scholar
15. Niblett, LI. T. Divergence and flutter of swept-forward wings with cross-flexibilities, RAE Technical Report 80047, 1980.Google Scholar
16. Niblett, LI. T. The minimum flutter speeds of flexibly-mounted rigid wings, RAE Technical Report 86054, 1986.Google Scholar
17. Lambourne, N. C. On the conditions under which energy can be extracted from an air stream by an oscillating aerofoil, Aeronaut Q, 1953, (4), 5468.Google Scholar
18. Nissim, E. Flutter suppression using active controls based on the concept of aerodynamic energy, NASA TN D6199, 1971.Google Scholar
19. Templeton, H. Use of a geared flap to prevent wing flutter, RAE Report Structures 151, 1953.Google Scholar
20. Turner, M. R. Active control of near frequency coalescence flutter, In: Collected papers, International Symposium on Aeroelasticity, Nuremberg, 1981, 308318.Google Scholar
21. Hassig, H. J. An approximate true damping solution of the flutter equation by determinant iteration, J Aircr, 1971, 8, 885889.Google Scholar
22. Rodden, W. P., Harder, R. L. and Bellinger, E. D. Aeroelastic Addition to Nastran, MacNeal-Schwendler Corporation, 1978.Google Scholar
23. Lawrence, A. J. and Jackson, P. Comparison of different methods of assessing the free oscillatory characteristics of aeroelastic systems, ARC CP1084, 1970.Google Scholar
24. Schofield, M. J. Methods of flutter solution with matched frequency parameter aerodynamics, Hawker Siddeley Aviation Report HSA(H)-AR-GEN/180/MJS, 1972.Google Scholar
25. Woodcock, D. L. and Lawrence, A. J. Further comparisons of different methods of assessing the free oscillatory characteristics of aeroelastic systems, RAE Technical Report 72188, 1972.Google Scholar
26. Baldock, J. C. A. A technique for analysing the results of a flutter calculation, ARC R&M3765, 1973.Google Scholar
27. Baldock, J. C. A. The identification of the flutter mechanism from a large-order flutter calculation, ARC R&M3832, 1978.Google Scholar