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Noise radiation from a ducted rotor in a swirling-translating flow

Published online by Cambridge University Press:  10 December 2009

ERIKA QUARANTA
Affiliation:
Fluid Mechanics and Computational Science Group, Department of Aerospace Sciences, Cranfield University, Cranfield MK43 0AL, UK
DIMITRIS DRIKAKIS*
Affiliation:
Fluid Mechanics and Computational Science Group, Department of Aerospace Sciences, Cranfield University, Cranfield MK43 0AL, UK
*
Email address for correspondence: d.drikakis@cranfield.ac.uk

Abstract

This paper investigates the noise radiation produced by a rotor inside a duct, which is convected by a swirling-translating mean flow. The study is based on an extension of Gennaretti's and Morino's boundary element method to the frequency domain for scattering problems in conjunction with a spinning rotor source model in the presence of a swirl flow. The proposed formulation is validated against exact solutions and is further used to investigate the effects of the translating flow Mach number and swirling flow angular velocity on noise radiation to the far field. The scattered sound is highly affected by the convecting mean flow. The modal content of the scattered field increases when increasing the translating flow Mach number, while a swirling flow leads to a reduction of the mode propagation, if co-rotating with respect to the azimuthal order of the spinning source, or an increase of the modal content, if counter-rotating with respect to the source. In general, the mean translating flow moves the main lobes of the directivity patterns downstream, while in some cases the mean swirling flow neglects this effect and the downstream lobe is completely shifted.

Type
Papers
Copyright
Copyright © Cambridge University Press 2009

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References

REFERENCES

Casalino, D., di Francescantonio, P. & Druon, Y. 2004 Gfd prediction of fan noise propagation. In 10th AIAA/CEAS Aeroacoustics Conference, Manchester, UK, AIAA Paper 2004–2989.Google Scholar
Chapman, C. J. 1994 Sound radiation from a cylindrical duct. Part I. Ray structure of the duct modes and of the external field. J. Fluid Mech. 281, 293311.Google Scholar
Cooper, A. J. & Peake, N. 2005 Upstream-radiated rotor-stator interaction noise in a mean swirling flow. J. Fluid Mech. 523, 219250.CrossRefGoogle Scholar
Crighton, D. G., Dowling, A. P., Ffowcs Williams, J. E., Heckl, M. A. & Leppington, F. G. 1992 Modern Methods in Analytical Acoustics. Springer.CrossRefGoogle Scholar
Dunn, M. H., Tweed, J. & Farassat, F. 1996 The prediction of ducted fan engine noise via a boundary integral equation method. In 2nd AIAA/CEAS Aeroacoustics Conference, State College, PA, AIAA Paper 96–1770.Google Scholar
Eversman, W. & Roy, I. D. 1993 Ducted fan acoustic radiation including the effects of non-uniform mean flow and acoustic treatment. In 15th AIAA/CEAS Aeroacoustics Conference, Long Beach, CA, AIAA Paper 93–4424.Google Scholar
Garrick, I. E. & Watkins, C. W. 1953 A theoretical study of the effect of forward speed on the free-space sound-pressure field around propellers. Tech. Rep. TN 3018. NACA.Google Scholar
Gennaretti, M., Luceri, L. & Morino, L. 1997 A unified boundary integral methodology for aerodynamics and aeroacoustics of rotors. J. Sound Vib. 200 (4), 467489.CrossRefGoogle Scholar
Gennaretti, M. & Morino, L. 1992 A boundary element method for the potential, compressible aerodynamics of bodies in abitrary motion. Aeronaut. J. 96, 1519.Google Scholar
Gobulev, V. V. & Atassi, H. M. 2000 Unsteady swirling flows in annular cascades. Part 1. Evolution of incident disturbances. AIAA J. 38 (7), 11421149.Google Scholar
Goldstein, M. E. 1976 Aeroacoustics. McGraw-Hill.Google Scholar
Heaton, C. J. & Peake, N. 2006 Algebraic and exponential instability of inviscid swirling flow. J. Fluid Mech. 565, 279318.CrossRefGoogle Scholar
Lyrintzis, A. S. 2003 Surface integral methods in computational aeroacoustics – from the (cfd) near-field to the (acoustic) far-field. Intl J. Aeroacoust. 2 (2), 95128.Google Scholar
Morino, L. 1993 Boundary integral equations in aerodynamics. Appl. Mech. Rev. 46 (8), 445466.Google Scholar
Morino, L., Chen, L. & Suciu, E. 1975 Steady and oscillatory subsonic and supersonic aerodynamics around complex configurations. AIAA J. 13 (3), 368374.CrossRefGoogle Scholar
Morino, L. & Tseng, K. 1990 Boundary Element Methods in Nonlinear Fluid Dynamics. Elsevier Applied Science.Google Scholar
Tam, C. K. W. 2006 Recent advances in computational aeroacoustics. Fluid Dyn. Res. 38 (9), 591615.Google Scholar
Tam, C. K. W. & Auriault, L. 1998 The wave modes in ducted swirling flows. J. Fluid Mech. 371, 120.CrossRefGoogle Scholar