Hostname: page-component-78c5997874-t5tsf Total loading time: 0 Render date: 2024-11-15T02:12:00.473Z Has data issue: false hasContentIssue false
  • English
  • Français

A New Concept in the Design of Jet Engine Mufflers and Test Cells

Published online by Cambridge University Press:  28 July 2016

E. J. Richards  and
D. J. Evans
E. J. Richards
Affiliation:
Department of Aeronautical Engineering, University of Southampton
D. J. Evans
Affiliation:
Department of Aeronautical Engineering, University of Southampton
Get access Rights & Permissions [Opens in a new window]

Summary

A new concept is put forward which should help materially in the design of engine test cells and ground mufflers. It is suggested that a relatively small spreader can be added behind a jet nozzle which changes, the shape of the jet from circular to a long annular slot. The frequency rise which may be obtained in this way is used to reduce low frequency noise, possibly at the expense of more easily attenuated high frequency noise. As a modest example, tests are described on one particular version which gives an attenuation in the most important low frequency range of nearly 20 decibels. It is shown that the back pressure on the engine is negligible even with a cooling flow equal to the engine mass flow. Other applications are discussed and tested, while suggestions for full scale installations are made.

Type
Research Article
Information
The Aeronautical Journal , Volume 61 , Issue 561 , September 1957 , pp. 619 - 630
Copyright
Copyright © Royal Aeronautical Society 1957

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. Richards, E. J. (1953). Research on Aerodynamic Noise from Jets and on Associated Problems. Journal of the Royal Aeronautical Society, May 1953.Google Scholar
2. Symposium on Aeronautical Acoustics. Journal of the Royal Aeronautical Society, April 1954.Google Scholar
3. Powell, A. (1954). On the reduction of choked jet noise. Proc. Phys. Soc. B., Vol. 67, p. 313, 1954.Google Scholar
4. Greatrex, F. B. (1956). Jet Engine Noise. Anglo-American Aeronautical Conference, Los Angeles 1955. Institute of the Aeronautical Sciences. 1956.Google Scholar
5. Franklin, R. E. (1955). Noise Measurements on Cold Jets Using Convergent Divergent Nozzles. Communicated by Prof. E. J. Richards. A.R.C. 17 986, F.M. 2324, Strut. 1833. 5th November 1955.Google Scholar
6. Powell, A. (1955). The Problem of Structural Failure due to Jet Noise. Communicated by Prof. E. J. Richards. A.R.C. 17 514-0.1177. 29th March 1955. Corrigenda, 31st May 1955.Google Scholar
7. Franklin, R. E. (1955). A Note on the Experience to Date of the Vibration of Aircraft Structures Excited by Jet Noise and Comments Thereon. Communicated by Prof. E. J. Richards. A.R.C. 17 515-0.1178. 29th March 1955. Confidential.Google Scholar
8. Westley, R. and Lilley, G. M. (1952). An Investigation of the Noise Field from a Small Jet and Methods for its Reduction. College of Aeronautics Report No. 53. A.R.C. 14 719, F.M. 1692, E.P. 174. January 1952. And Errata– received 26th May 1952.Google Scholar
9. Richards, E. J. (1955). Noise Problems in Helicopter Design. Journal of the Helicopter Association of Great Britain, July 1955.Google Scholar
10. Hollingsworth, M. A. and Richards, E. J. (1955). A Schlieren Study of the Interaction between a Vortex and a Shockwave in a Shock Tube. A.R.C. 17 985, F.M. 2323, 5th November, 1955.Google Scholar
11. Ingard, Uno (1953). A Review of the Influence of Meteorological Conditions on Sound Propagation. Journal of the Acoustical Society of America, Vol. 25, May 1953.Google Scholar
12. Bristol Aeroplane Co. Private communication.Google Scholar
13. Evans, D. J. (1955). University of Southampton. Thesis submitted for the degree of M.Sc, 1955.Google Scholar
14. Powell, A. (1954). The Influence of Exit Velocity Profile on the Noise of a Jet. The Aeronautical Quarterly, Vol. 4, p. 341, 1954.Google Scholar
15. Lemmerman, R. D. (1953). Materials and Structures Problems in Aircraft Noise Control. Journal of the Acoustical Society of America, Vol. 25. No. 3, May 1953.Google Scholar
16. National Physical Laboratory Report G.C. 934/54/2.Google Scholar