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Noise From Turbojet Compressors

Published online by Cambridge University Press:  04 July 2016

S. L. Bragg  and
R. Bridge
S. L. Bragg
Affiliation:
Rolls-Royce Ltd.
R. Bridge
Affiliation:
Rolls-Royce Ltd.
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Summary

The noise radiated from the intakes of turbojet engines during landing is already causing a serious nuisance. This paper, which is largely based on the deliberations of an ad hoc working panel of academic experts formed by Rolls-Royce in 1961, describes the characteristics of the noise and discusses possible mechanisms of generation. The noise appears to be dipole in origin, and to come mainly from the first two compressor stages. It consists of a few discrete tone components, generated mainly by the interactions which occur when one row of aerofoils passes through the wakes of a preceding row; and broad band noise resulting from the turbulence in the wakes and the inherent instability of the boundary layer on the aerofoils.

Some discrete tones may be eliminated over part of the running range by suitable choice of blade numbers and disposition. The broad band noise is unlikely to be reduced without major design modifications involving either a reduction of the air speed relative to the front stage blades, or removal of the boundary layer at their trailing edges.

Type
Research Article
Information
The Aeronautical Journal , Volume 68 , Issue 637 , January 1964 , pp. 1 - 10
Copyright
Copyright © Royal Aeronautical Society 1964

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References

1.Greatrex, F. B.By-pass Engine Noise. SAE Preprint 162C (1960), S.A.E. Trans., Vol. 69, p. 312, 1961.Google Scholar
2.Tyler, J. M. and Sofrin, T. G. Axial Flow Compressor Noise Studies. S.A.E. Paper 345-D, 1961: alsoCrossRefGoogle Scholar
*Bridge, R. Engine Noise Discrete Tones. R.R. Ref. 1/BBM, 12th May 1961.Google Scholar
*Bragg, S. L. Transmission of Rotating Pressure Fields. R.R. Ref. 2/BM, 7th June 1961 and 4/BS, 1st January 1962.Google Scholar
*Doak, P. E. Notes on Propagation of Engine Intake Noise, Parts I (April 1961) and II (June 1961).Google Scholar
Pearson, H. Tyler and Sofrin's Theory of Rotor-Stator Interaction. R.R. Ref. 1/MH, 21st July 1961.Google Scholar
3.Kemp, N. H.Journal of the Aeronautical Sciences, Vol. 19, p. 713, October 1952.Google Scholar
4.Kemp, N. H. and Sears, W. R.Journal of the Aeronautical Sciences, Vol. 20, p. 585, September 1953.CrossRefGoogle Scholar
*Hetherington, R.The Noise Generated by Fluctuating Lift. R.R. Ref. 4/BS, 14th December 1961. This later appeared in A.I.A.A. Journal, Vol. 1, p. 473, February 1963.Google Scholar
5.Morse, P. M.Vibration and Sound. McGraw-Hill, 2nd Ed., 1948.Google Scholar
6.* Williams, D. J. M. and Sharland, I. J. (Southampton University). An Experiment on the Noise from a Flat Plate Aerofoil in a Turbulent Subsonic Jet, May 1961. (This subsequently formed part of a paper to the Fourth Int. Congress on Acoustics, Copenhagen, 1962).Google Scholar
7.Whitehead, D. S.Aeronautical Research Council, R. & M. 3253, August 1960.Google Scholar
8.* Lilley, G. M. On the Vortex Noise from Airscrews, Fans and Compressors, August 1961.Google Scholar
9.* Phillips, O. M. Sound Radiation from Boundary Layer Turbulence, February 1962.Google Scholar
10.* Griffiths, J. W. R. Spectrum of Sound Generated by a Compressor, January 1962; alsoGoogle Scholar
*Bragg, S. L. Effect of Minor Dissimilarities Between Blades in a Compressor Row. R.R. Ref. 1/BS, 10th August 1961.Google Scholar
11.Hetherington, R. On the Propagation of Sound Through a Moving Blade Row. R.R. Ref. 5/BM, 28th March 1963. Other relevant papers submitted to the Panel for discussion included:Google Scholar
*Phillips, O. M. A Note on the Sound Generated by a Disc of Blades Operating in a Turbulent Airstream, March 1961.Google Scholar
*Phillips, O. M. Wake Interactions Between Successive Blade Rows, August 1961.Google Scholar
*Lilley, G. M. The Propagation of Sound Along a Duct Having a Non-Uniform Axial Mean Flow, December 1961.Google Scholar
*Morfey, C. L. (Southampton University). Transmission of Discrete Frequency Noise from a Ducted Fan, January 1962. This subsequently formed part of a paper to the Fourth Int. Congress on Acoustics, Copenhagen, 1962.Google Scholar
*Coles, G. M. Compressor Overall Sound Power Levels. R.R. Ref. 1/MA, 26th February 1962.Google Scholar
*Bragg, S. L. Transmission of Sound in an Annular Duct of Varying Area. R.R. Ref. 8/BM, 14th March 1962.Google Scholar
*Bragg, S. L. Noise Produced by a Flexible Blade Moving Through a Series of Wakes. R.R. Ref. OH 54, May 1962.Google Scholar
*Sharland, I. J. (Southampton University). Summary of Recent Experimental Work on the Southampton University Fan Rig, November 1962.Google Scholar
Bridge, R. Amplitude Modulations in Engine Noise. R.R. Ref. 10/CHB, 1st March 1963.Google Scholar