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The generation of sound in turbulent motion

Published online by Cambridge University Press:  03 February 2016

G. M. Lilley
G. M. Lilley*
Affiliation:
Aeronautics and Astronautics, University of Southampton, Southampton, UK
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Abstract

The present paper reviews and discusses the physical mechanisms of noise generation and reduction in turbulent flows with their applications towards aircraft noise reduction at takeoff and on the approach. This work began in 1948 when Lilley undertook an experimental investigation into the source of jet noise as a necessary precursor to finding methods for the reduction of high speed jet engine noise on civil jet airliners. Westley and Lilley completed this experimental programme in 1951, which included the design of a range of devices for high speed jet noise reduction. It was about this time that similar studies on jet noise were being started elsewhere and in particular by Lassiter and Hubbard in USA. The major contribution to the subject of turbulence as a source of noise came from Sir James Lighthill’s remarkable theory in 1952. In spite of the difficulties attached to theoretical and experimental studies on noise from turbulence, it is shown that with the accumulated knowledge on aerodynamic noise over the past 50 years, together with an optimisation of aircraft operations including flight trajectories, we are today on the threshold of approaching the design of commercial aircraft with turbofan propulsion engines that will not be heard above the background noise of the airport at takeoff and landing beyond 1-2km, from the airport boundary fence.

It is evident that in the application of this work, which centres on the physical mechanisms relating to the generation of noise from turbulence and turbulent shear flows, to jet noise, there is not one unique mechanism of jet noise generation for all jet Mach numbers. This author in this publication has concentrated on what appears to be the dominant mechanism of noise generation from turbulence, where the mean convection speeds of the turbulence are subsonic. The noise generated at transonic and supersonic jet speeds invariably involves extra mechanisms, which are only briefly referred to here.

Type
Research Article
Information
The Aeronautical Journal , Volume 112 , Issue 1133 , July 2008 , pp. 381 - 394
Copyright
Copyright © Royal Aeronautical Society 2008 

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References

1. Westley, R. and Lilley, G.M., An investigation of the noise from a small jet and methods for its reduction, 1952, College of Aeronautics, Cranfield Report 53.Google Scholar
2. Lighthill, M.J., On sound generated aerodynamically: General theory, Proceedings Royal Society London (A), 1952, 211, pp 564–587.Google Scholar
3. Shott, G.A., Electromagnetic Radiation, 1912, CUP.Google Scholar
4. Lilley, G.M., On the noise from airjets, Noise Mechanisms, 1974, AGARD CP 131, pp 13.1–13.12.Google Scholar
5. Ffowcs Williams, J.E., The noise from turbulence convected at high speed, 1963, Phil Trans Royal Society London (A), 255, pp 469–503.Google Scholar
6. Lilley, G.M., On the noise from air jets, 1958, ARC 20376.Google Scholar
7. Ribner, H.S., The generation of sound in turbulent jets, Advances in Applied Mechanics, 1964, 8, pp 102–182, Academic Presss.Google Scholar
8. Brekhovskikh, N.K., Waves in Layered Media, 1960, Academic Press.Google Scholar
9. Goldstein, M.E., Aeroacoustics, 1976, McGraw-Hill, New York.Google Scholar
10. Lilley, G.M., Sound generation in shear flow turbulence, Fluid Dynamics, 1971, Trans (Poland), 6, pp 405–420.Google Scholar
11. Howe, M.S., Contributions to the theory of aerodynamic noise, J Fluid Mech, 1975, 71, pp 625–673.Google Scholar
12. Lilley, G.M., The sound field from a small high speed jet, 1952, Proceedings of the 8th International Congress of Applied Mechanics. p 354.Google Scholar
13. Bogey, C., Bailly, C. and Juve, D., Noise investigation of a high subsonic moderate Reynolds number jet using a compressible large eddy simulation, Theoretical and Computational Fluid Dynamics, 2003, 16, pp 273–297.Google Scholar
14. Tam, C.K.W., Jet noise large scale motion, Aeroacoustics of Flight Vehicles, Theory and Practice, Vol 1: Noise Sources, 1991, Hubbard, H.H. (Ed), Chap 6, NASA RP-1258.Google Scholar
15. Lilley, G.M., The source of aerodynamic noise, Int J Aeroacoustics, 2003, 2, pp 241–254.Google Scholar
16. L’vov, V.S. and Mikhailov, A.V., Sound and hydrodynamic turbulence, Sov Phys JETP, 1978, 47, p 756.Google Scholar
17. Dowling, A.P., Ffowcs Williams, J.E. and Goldstein, M.E., Sound production in a moving stream, 1978, Phil Trans Royal Society London (A), 288, pp 321–349.Google Scholar
18. Ffowcs Williams, J.E. and Hawkings, D.L., Sound generated by turbulence, Phil Trans Royal Society London (A), 1969, 264, pp 321–342.Google Scholar
19. Morfey, C.L. and Wright, M.C.M., Extension of Lighthill’s acoustic analogy with applications to computational acoustics, Proceedings Royal Society London (A), 2007, 463, pp 2101–2127.Google Scholar
20. Lilley, G.M., The generation and radiation of supersonic jet noise, 1972, AFAPL, 4, TR72-53, Lockheed-Georgia.Google Scholar
21. Townsend, A.A., The Structure of Turbulent Shear Flow, 1976, CUP.Google Scholar
22. Lilley, G.M., Wall pressure fluctuations under turbulent boundary layers at subsonic and supersonic speeds, 1963, AGARD report 454.Google Scholar
23. Kline, S.J., Reynolds, W.C., Schraub, W.C. and Runstadler, P.W., The structure of the turbulent boundary layer, J Fluid Mech, 30, pp 741–773.Google Scholar
24. Van Dyke, M., An Album of Fluid Motion, 1982, The Parabolic Press, Stanford, California, US.Google Scholar
25. Morris, P.J., Giridharan, M.G. and Lilley, G.M., On the turbulent mixing of compressible free shear layers, Proceedings Royal Society London (A), 1990, 431, pp 219–243.Google Scholar
26. Brown, G.L. and Roshko, A., On density effects and large structure in turbulent mixing layers, J Fluid Mech, 1974, 64, pp 775–816.Google Scholar
27. Pridmore-Brown., D.C., Sound generation in a fluid flowing through an attenuating duct, J Fluid Mech, 1958, 4, pp 393–406.Google Scholar
28. Tam, C.K.W. and Auriault, L., Jet mixing from small scale turbulence, AIAA J, 2002, 37, (2), pp 145–153.Google Scholar
29. Lilley, G.M., A study of the silent flight of the owl, 1998, AIAA 98-2340.Google Scholar
30. Lockard, D. and Lilley, G.M., The airframe noise prediction challenge, 2004, NASA TM-2004-21301.Google Scholar
31. Hileman, J.L., Spakovsky, Z.S., Drela, M. and Sargeant, M.A., Aerodynamic and aeroacoustic three-dimensional design for a ‘silent’ aircraft, 2006, AIAA 2006-241.Google Scholar