Hostname: page-component-cd9895bd7-hc48f Total loading time: 0 Render date: 2024-12-27T13:54:11.840Z Has data issue: false hasContentIssue false
  • English
  • Français

Vibration Characteristics of Pre-twisted Blades of Asymmetrical Aerofoil Cross-Section

Published online by Cambridge University Press:  07 June 2016

W. Carnegie  and
B. Dawson
W. Carnegie
Affiliation:
University of Surrey
B. Dawson
Affiliation:
University of Surrey
Get access

Summary

The natural frequencies and mode shapes of vibration of cantilever aerofoil cross-section blades of pre-twist angle in the range 0 to 90 degrees are obtained. The beams are 152·4 mm long and the width / thickness ratio is such that they may be regarded as slender. Theoretical frequency ratios and mode shapes of vibration, neglecting shear and rotary inertia effects, are obtained for two sets of beams, one with clockwise pre-twist relative to the root cross-section and the other with anti-clockwise pre-twist. The effect of variation in the value of the centre-of-flexure coordinates upon the natural frequency ratios and mode shapes of vibration is investigated. The theoretical results are compared to corresponding experimental results.

Type
Research Article
Information
Aeronautical Quarterly , Volume 22 , Issue 3 , August 1971 , pp. 257 - 273
Copyright
Copyright © Royal Aeronautical Society. 1971

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. Isakson, G. and Eisley, G. J. Natural frequencies in coupled bending and torsion of twisted rotating and non-rotating blades. NASA, 1964. (Prepared under Grant No. NS6-27-59 by the University of Michigan.)Google Scholar
2. Mendelson, A. and Gendler, S. Analytical and experimental investigation of effect of twist on vibrations of cantilever beams. NACA TN 2300, 1951.Google Scholar
3. Houbolt, J. C. and Brook, G. W. Differential equations of motion for combined flapwise bending, chordwise bending and torsion of twisted non-Uniform rotor blades. NACA Technical Report 1346, 1958.Google Scholar
4. Carnegie, W. Vibration of pre-twisted cantilever blading. Proceedings, Institution of Mechanical Engineers, Vol. 173, No. 12, 1959.CrossRefGoogle Scholar
5. Montoya, J. Coupled bending and torsional vibrations in a twisted rotating blade. Brown-Boveri Review, Vol. 53, No. 3, 1966.Google Scholar
6. Carnegie, W. and Dawson, B. Vibration characteristics of straight blades of asymmetrical aerofoil cross-section. Aeronautical Quarterly, Vol. XX, p. 178, May 1969.CrossRefGoogle Scholar
7. Diprima, R. C. and Handelman, G. H. Vibrations of twisted beams. Quarterly of Applied Mathematics, Vol. XII, No. 3, p. 241, 1954.CrossRefGoogle Scholar
8. Dawson, B. The Ritz method applied to the vibration of pre-twist cantilever beams allowing for rotary inertia and shear deformation. To be published in the Journal of the American Society of Mechanical Engineers, (Brief Notes). (Accepted for publication).Google Scholar
9. Lance, G. N. Numerical methods for high speed computers. Iliffe, London, 1960.Google Scholar
10. Dawson, B. Coupled bending-bending vibrations of pre-twist cantilever blading treated by the Rayleigh-Ritz Energy Method. Journal of Mechanical Engineering Science, Vol. 10, No. 5, 1968.CrossRefGoogle Scholar
11. Carnegie, W. Experimental determination of the centre-of-flexure and centre-of-torsion coordinates of an asymmetrical aerofoil cross-section. Journal of Mechanical Engineering Science, Vol. 1, No. 3, 1962.Google Scholar