Hostname: page-component-586b7cd67f-r5fsc Total loading time: 0 Render date: 2024-11-28T11:04:53.123Z Has data issue: false hasContentIssue false

The Influence of the Wake on the Flutter and Vibration of Rotor Blades*

Published online by Cambridge University Press:  07 June 2016

J. P. Jones*
Affiliation:
University of Southampton
Get access

Summary

An approximate theory is described which takes into account the influence of the wake on the aerodynamic derivatives of an oscillating rotor blade. It is shown that the most important parameter is the number of cycles of the oscillation which occur during one revolution of the rotor. For integral values of this parameter the flexural damping is shown to become very small at small angles of incidence. The flutter characteristics of a simple rotor blade are calculated on the basis of this theory, and it is found that the wake causes radical changes in the critical speeds. The theory is in good qualitative agreement with experiment.

Type
Research Article
Copyright
Copyright © Royal Aeronautical Society. 1958

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

*

Tbe material in this paper is based on a report submitted to the Department of Scientific and Industrial Research in June 1954, which was later extended and circulated as A.R.C. Report 18,173, in January 1956. The present paper was received for The Aeronautical Quarterly in October 1957.

References

1. Simpkinson, Scott H., Eatherton, Laurel I. and Millenson, Morton B. The Influence of Centrifugal Force on the Elastic Curve of a Rotating Beam. N.A.C.A. Report 914, 1948.Google Scholar
2. Hirsch, Alfred M. The Contribution of Higher Mode Resonance to Rotor Blade Bending. Journal of the Aeronautical Sciences, June 1953.Google Scholar
3. Jnr.Meyer, John R. An Investigation of Bending Moment Distribution on a Model Helicopter Blade. N.A.C.A. T.N. 2626, February 1952.Google Scholar
4. Daughaday, H. and Kline, J. Cornell Aeronautical Laboratory Report C.A.L.-52, November 1953.Google Scholar
5. Mangler, K. and Squire, H. B. The Induced Flow of a Lifting Rotor. R. & M. 2642, May 1950.Google Scholar
6. Daughaday, H. and Kline, J. An Investigation of the Effect of Virtual Delta-Three Angle and Blade Flexibility on Rotor Blade Flutter. Cornell Aeronautical Laboratory Report, SB-862-S-2, August 1954.Google Scholar
7. Prandtl, L. Appendix to a paper by Betz in Vier Abhandlungen zur Hydrodynamik und Aerodynamik, Göttingen, 1927. (See R. & M. 1483 by Lock and Yeatman, February 1932.)Google Scholar
8. Jones, W. P. Aerodynamic Forces on Wings in Non-Uniform Motion. R. & M. 2117, August 1945.Google Scholar
9. Lynam, E. Notes on the Flutter of Airscrew Blades. R. & M. 1258. April 1929.Google Scholar