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The absorption of sound by perforated linings

Published online by Cambridge University Press:  26 April 2006

I. J. Hughes  and
A. P. Dowling
I. J. Hughes
Affiliation:
Topexpress Ltd. Poseidon House, Castle Park, Cambridge CB3 0RD, UK
A. P. Dowling
Affiliation:
Department of Engineering, University of Cambridge, Cambridge CB2 1PZ, UK
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Abstract

The efficiency of a perforated screen as a sound absorber can be greatly increased when a rigid surface is placed behind the screen, essentially because the sound can then interact many times with the perforations. We consider a practical application for a backed perforated screen with a bias flow through the perforations: the ‘screech liner’. This is a perforated lining which is inserted in the afterburner section of jet engines to suppress the acoustically driven combustion instability commonly known as screech. A pressure drop across the screen ensures that a bias flow of cool air is produced; this flow protects the liner from the intense heat in the afterburner.

Our analysis was developed in answer to a clear need for a theory which can predict the optimal geometry and bias flow to produce a highly absorptive liner. We show that it is theoretically possible to absorb all the sound at a particular frequency. Experimental results are presented which show encouraging agreement with the theoretical predictions.

Screech is thought to be the excitation of a transverse resonant oscillation in the jet pipe, but the insertion of a liner inevitably changes the frequency of such resonances because the boundary condition at the wall is altered. We examine the effect of a liner on the resonances which occur in a cylinder and show that a well-designed liner may suppress resonances over a range of frequencies.

The effect of the hot axial jet flow on the performance of a liner has not previously received attention. A simple model to account for this flow is included in our analysis.

Type
Research Article
Information
Journal of Fluid Mechanics , Volume 218 , September 1990 , pp. 299 - 335
Copyright
© 1990 Cambridge University Press

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References

Abramowitz, M. & Stegun, I. A., 1965 Handbook of Mathematical Functions. Dover.
Barthel, F.: 1958 Untersuchungen über nichtlineare Helmholtz-Resonatoren (Investigations on nonlinear Helmholtz resonators). Frequenz 12, 1–11.Google Scholar
Bechert, D. W.: 1980 Sound absorption caused by vorticity shedding, demonstrated with a jet flow. J. Sound Vib. 70, 389–405.Google Scholar
Blackman, A. W.: 1960 Effect of nonlinear losses on the design of absorbers for combustion in stabilities. Am. Rocket Soc. J., November, 1022–1028.Google Scholar
Bloxsidge, G. J., Dowling, A. P. & Langhorne, P. J., 1988 Reheat buzz: an acoustically coupled combustion instability. Part 2. Theory. J. Fluid Mech. 193, 445–473.Google Scholar
Boden, H. & Abom, M., 1986 Influence of errors on the two-microphone method for measuring acoustic properties in ducts. J. Acoust. Soc. Am. 79, 541–549.Google Scholar
Cummings, A.: 1983 Acoustic nonlinearities and power losses at orifices. AIAA J. 22, 786–792.Google Scholar
Cummings, A.: 1984 Transient and multiple frequency sound transmission through perforated plates at high amplitude. AIAA Paper 84–2311.Google Scholar
Dean, P. D. & Tester, B. J., 1975 Duct wall impedance control as an advanced concept for acoustic suppression. NASA CR-134998.Google Scholar
Garrison, G. D., Schnell, A. C., Baldwin, C. D. & Russel, P. R., 1969 Suppression of combustion oscillations with mechanical damping devices. Interim Rep. Pratt & Whitney Aircraft FR-3299.
Howe, M. S.: 1979 On the theory of unsteady high Reynolds number flow through a circular aperture. Proc. R. Soc. Lond. A 366, 205–223.Google Scholar
Ingard, U. & Labate, S., 1950 Acoustic circulation effects and the nonlinear impedance of orifices. J. Acoust. Soc. Am. 22, 211–218.Google Scholar
Leppington, F. G. & Levine, H., 1973 Reflexion and transmission at a plane screen with periodically arranged circular or elliptical apertures. J. Fluid Mech. 61, 109–127.Google Scholar
Lewis, G. D. & Garrison, G. D., 1971 The role of acoustic absorbers in preventing combustion instability. AIAA Paper 71-699.Google Scholar
Markstein, G. H.: 1964 Non-steady Flame Propagation. Pergamon.
Melling, T. H.: 1973 The acoustic impedance of perforates at medium and high sound pressure levels. J. Sound Vib. 29, 1–65.Google Scholar
Morse, P. M. & Ingard, K. U., 1968 Theoretical Acoustics. McGraw-Hill.
Rayleigh, Lord: 1899 On the theory of resonance. In Scientific Papers, Vol. 1. Cambridge University Press.
Rayleigh, Lord: 1945 The Theory of Sound, vol. ii. Dover, re-issue.
Seybert, A. F. & Ross, D. F., 1977 Experimental determination of acoustic properties using a two-microphone random-excitation technique. J. Acoust. Soc. Am. 61, 1362–1370.Google Scholar
Seybert, A. F. & Soenarko, B., 1981 Error analysis of spectral estimates with application to the measurement of acoustic parameters using random sound fields in ducts. J. Acoust. Soc. Am. 69, 1190–1199.Google Scholar
Zinn, B. T.: 1970 A theoretical study of non-linear damping by Helmholtz resonators. J. Sound Vib. 13, 347–356.Google Scholar