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On broadband jet–ring interaction noise and aerofoil turbulence-interaction noise predictions

Published online by Cambridge University Press:  05 May 2010

MICHEL ROGER*
Affiliation:
Laboratoire de Mécanique des Fluides et Acoustique, École Centrale de Lyon, Ecully 69134, France
*
Present address: Centre Acoustique, École Centrale de Lyon, 36 Av. Guy de Collongue, 69134 Ecully, France. Email address for correspondence: michel.roger@ec-lyon.fr

Abstract

The aerodynamic noise of a thin rigid annulus (referred to as the ring here) placed in the mixing layer of a subsonic circular jet is investigated in the paper, both theoretically and experimentally. From the experimental point of view, the jet–ring configuration is understood as an axisymmetric alternative to more usual ones involving a rectangular aerofoil held between parallel side plates, dedicated to the study of the noise due to the impingement of upstream turbulence. The main advantages of the circular geometry are a minimum background noise, the absence of tip effects and more specifically the account for all radiation angles from the surface in the far-field acoustic signature. The circular set-up is well suited for the study of pure broadband interaction noise only if the flow remains free of self-sustained oscillations. This is ensured by keeping a sufficient interaction distance between the nozzle and the ring, and by shaping serrations on the nozzle lip. From the theoretical point of view, an analytical model is derived as a straightforward extension of existing formulations. The induced unsteady lift forces on the ring are first inferred from a linearized unsteady aerodynamic theory and the far field is calculated in a second step by a radiation integral. This relates the far-field acoustic pressure power spectral density (PSD) to the two-wavenumber spectrum of the radial turbulent velocity at the ring location, by means of an aeroacoustic transfer function. The latter is shown asymptotically identical to the one detailed in the Appendix for a rectangular aerofoil, in the limit of relatively high frequencies. The analytical acoustic predictions are found to agree well with the measurements over an extended frequency range, provided that the model is fed with turbulent velocity input data measured by a hot-wire probe. Indirectly, this agreement validates the transfer function for a rectangular aerofoil at oblique radiation angles, which is not achievable in a set-up involving side plates and a rectangular nozzle.

Type
Papers
Copyright
Copyright © Cambridge University Press 2010

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References

REFERENCES

Abramowitz, M. & Stegun, I. A. 1970 Handbook of Mathematical Functions. Dover.Google Scholar
Amiet, R. K. 1975 Acoustic radiation from an airfoil in a turbulent stream. J. Sound Vib. 41 (4), 407420.CrossRefGoogle Scholar
Amiet, R. K. 1976 High frequency thin-airfoil theory for subsonic flow. AIAA J. 14 (8), 10761082.CrossRefGoogle Scholar
Bradshaw, P., Ferris, D. H. & Johnson, R. F. 1964 Turbulence in the noise-producing region of a circular jet. J. Fluid Mech. 19 (4), 591624.CrossRefGoogle Scholar
Brooks, T. F. & Humphreys, W. M. Jr., 2003 Flap-edge aeroacoustic measurements and predictions. J. Sound Vib. 261 (1), 3174.CrossRefGoogle Scholar
Curle, N. 1955 The influence of solid boundaries upon aerodynamic sound. Proc. R. Soc. A 231, 505514.Google Scholar
Ffowcs Williams, J. E. & Hawkings, D. L. 1969 Sound generation by turbulence and surfaces in arbitrary motion. Proc. R. Soc. 264, 321342.Google Scholar
Filotas, L. T. 1969 Theory of airfoil response in a gusty atmosphere. Part I. Aerodynamic transfer function. Tech. Rep. UTIAS Rep. No. 139. Institute for Aerospace Studies, University of Toronto.Google Scholar
Fleury, V., Bailly, C., Jondeau, E., Michard, M. & Juvé, D. 2008 Space-time correlations in two subsonic jets using dual particle image velocimetry measurements. AIAA J. 46 (10), 24982509.CrossRefGoogle Scholar
Fuchs, H. V. & Michel, U. 1978 Experimental evidence of turbulent source coherence affecting jet noise. AIAA J. 16 (9), 871872.CrossRefGoogle Scholar
Graham, J. M. R. 1970 Similarity rules for thin aerofoils in non-stationary subsonic flows. J. Fluid Mech. 43 (4), 753766.CrossRefGoogle Scholar
Hinze, J. O. 1975 Turbulence. McGraw-Hill.Google Scholar
Landahl, M. 1961 Unsteady Transonic Flows. Pergamon.Google Scholar
Lau, J. C. & Fisher, M. J. 1975 The vortex-street structure of turbulent jets. Part 1. J. Fluid Mech. 67 (2), 299337.CrossRefGoogle Scholar
Mish, P. F. & Devenport, W. J. 2006 An experimental investigation of unsteady surface pressure on an airfoil in turbulence. Part 1. Effects of mean loading. J. Sound Vib. 296 (3), 417446.CrossRefGoogle Scholar
Moreau, S. & Roger, M. 2005 Effect of angle of attack and airfoil shape on turbulence-interaction noise. In Eleventh AIAA/CEAS Aeroacoustics Conference, Monterey, CA.Google Scholar
Moreau, S., Schram, C. & Roger, M. 2007 Diffraction effects on the trailing edge noise measured in an open-jet anechoic wind tunnel. In Thirteenth AIAA/CEAS Aeroacoustics Conference, Rome, Italy.Google Scholar
Oerlemans, S. & Migliore, P. 2004 Aeroacoustic wind tunnel tests of wind turbine airfoils. In Tenth AIAA/CEAS Aeroacoustics Conference, Manchester, UK.Google Scholar
Olsen, W. A. 1976 Noise generated by impingement of turbulent flow on airfoils of varied chord, cylinders, and other flow obstructions. Tech. Rep. NASA-TM-X-73464.Google Scholar
Paterson, R. W. & Amiet, R. K. 1976 Acoustic radiation and surface pressure characteristics of an airfoil due to incident turbulence. Tech. Rep. CR 2733. NASA.CrossRefGoogle Scholar
Rockwell, D. & Naudascher, E. 1978 Review – self-sustaining oscillations of flow past cavities. J. Fluid Engng 100, 152163.CrossRefGoogle Scholar
Roger, M. & Moreau, S. 2005 Back-scattering correction and further extensions of Amiet's trailing-edge noise model. Part I. Theory. J. Sound Vib. 286, 477506.CrossRefGoogle Scholar
Roger, M. & Serafini, S. 2005 Interaction noise from a thin annulus in a circular jet. In Eleventh AIAA/CEAS Aeroacoustics Conference, Monterey, CA.Google Scholar
Ross, M. H., Shannon, D. W., Blake, W. K. & Morris, S. C. 2008 Unsteady lift and radiated sound generated by a 2-d airfoil in a single stream shear layer. In Fourteenth AIAA/CEAS Aeroacoustics Conference, Vancouver, Canada.Google Scholar
Schram, C. 2003 Aeroacoustics of subsonic jets: prediction of the sound produced by vortex pairing based on piv. PhD thesis, Technical University Eindhoven ISBN 90-386-1605-8, Eindhoven, The Netherlands.Google Scholar