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Reconstruction of Noise Source in a Ducted Fan Using a Generalized Nearfield Acoustical Holography
Technical Paper
2010-01-0416
ISSN: 0148-7191, e-ISSN: 2688-3627
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English
Abstract
The identification of the propulsion noise of turbofan engines plays an important role in the design of low-noise aircraft. The noise generation mechanisms of a typical turbofan engine are very complicated and it is not practical, if not impossible, to identify these noise sources efficiently and accurately using numerical or experimental techniques alone. In addition, a major practical concern for the measurement of acoustic pressure inside the duct of a turbofan is the placement of microphones and their supporting frames which will change the flow conditions under normal operational conditions. The measurement of acoustic pressures on the surface of the duct using surface-mounted microphones eliminates this undesirable effect. In this paper, a generalized acoustical holography (GAH) method that is capable of estimating aeroacoustic sources using surface sound pressure is developed. An indirect boundary element formulation is derived to generate the transfer matrix that relates aeroacoustic sources (monopoles and dipoles) to the measured surface sound pressure field. The surface sound pressure on the duct is measured and utilized to reconstruct the noise source in the ducted fan. The validity of the integrated numerical/experiment method is demonstrated by the good correlation of the measured sound pressure at verification locations with the pressure computed from reconstructed sources.
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Authors
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Citation
Zhang, W., Raveendra, S., Lee, M., and Bolton, J., "Reconstruction of Noise Source in a Ducted Fan Using a Generalized Nearfield Acoustical Holography," SAE Technical Paper 2010-01-0416, 2010, https://doi.org/10.4271/2010-01-0416.Also In
Optimization, Optical Measurement Nondestructive Testing Techniques, 2010
Number: SP-2295 ; Published: 2010-04-13
Number: SP-2295 ; Published: 2010-04-13
References
- Sijtsma, P., Rademaker, E.R., and Schulten, B.H.M., “Experimental validation of lifting surface theory for rotor-stator interaction noise generation”, AIAA Journal, Vol.36, No.6, June 1998, 900-906.
- Hubbard, H.H., editor, Aeroacoustics of Fight Vehicles - Theory and Practice, Volume 1: Noise Sources, NASA RP 1258, 1991.
- Berton, J., Tutorial: Aircraft Noise and its Prediction, NASA Glenn Research Center.
- Envia, E., “Fan noise reduction: an overview”, International Journal of Aeroacoustics, 1(1), 2002, 43-64.
- Huff, D.L., “Technology development of aircraft noise alleviation - Engine noise reduction research”, presentation made at the Hiller Aviation Museum, 2000.
- Owens, R.E., “Energy efficient engine performance system - aircraft integration evaluation”, NASA/CR 159488, 1979.
- Goldstein, M.E., Aeroacoustics, McGraw-Hill, Inc., 1976.
- Williams, E.G., Fourier Acoustics: Sound Radiation and Nearfield Acoustical Holography, ACADEMIC PRESS, 1999.
- Williams, E.G., Dardy, H.D., and Washburn, K.B., “Generalized nearfield acoustical holography for cylindrical geometry: Theory and experiment”, J. Acoust. Soc. Am. 81(2), 389-407 (1987).
- Williams, E.G., Houston, B.H., and Bucaro, J.A., “Broadband nearfield acoustical holography for vibrating cylinders”, J. Acoust. Soc. Am. 86, 674-679 (1989).
- Williams, E.G. and Maynard, J.D., “Holographic imaging without the wavelength resolution limit”, Physical Review Letters, 45(7), 1980, 554-557.
- Williams, E.G., Maynard, J.D., and Skudrzyk, E., “Sound source reconstructions using a microphone array”, J. Acoust. Soc. Am. 68(1), 340-344 (1980).
- Lee, M., Bolton, J.S., and Mongeau, L., “Application of cylindrical near-field acoustical holography to the visualization of aeroacoustic sources”, J. Acoust. Soc. Am. 114(2), 842-858 (2003).
- Maynard, J.D. and Williams, E.G., “Nearfield holography: A new technique for nose radiation measurement”, In Proceedings of NOISE-CON 81, pages 19-24, 1981.
- Williams, E.G. and Maynard, J.D., “Numerical evaluation of the Rayleigh integral for planar radiators using the FFT”, J. Acoust. Soc. Am. 72(6), 2020-2030 (1982).
- Maynard, J.D. and Williams, E.G. “Calibration and application of nearfield holography for intensity measurement”, In Proceedings of NOISE-CON 82, pages 707-710, 1982.
- Maynard, J.D., Williams, E.G. and Lee Y., “Nearfield acoustic holography: I. Theory of generalized holography and the development of NAH”, J. Acoust. Soc. Am. 78(4), 1395-1413 (1985).
- Williams, E.G., Dardy, H.D., and Fink, R.G., “Nearfield acoustical holography using an underwater automated scanner”, J. Acoust. Soc. Am. 78(2), 789-798 (1985).
- Williams, E.G., Dardy, H.D., and Fink, R.G., “A technique for measurement of structure-borne intensity in plates”, J. Acoust. Soc. Am. 78(6), 2061-2067 (1985).
- Williams, E.G., “Introduction and survey of recent developments in nearfield acoustical holography”, In Proceedings of NOISE-CON 88, pages 203-208, 1988.
- Washburn, K.B. and Williams, E.G., “Measurement techniques and results in broad-band, generalized nearfield acoustical holography”, In Proceedings of NOISE-CON 87, pages 649-654, 1987.
- Dargush, G.F., Raveendra, S.T., and Banerjee, P.K., “Boundary element formulations for structural acoustics including mean flow effects”, ASME Winter Annual Meeting, New Orleans, Computational Methods for Fluids/Structure Interaction, AMD-Vol 178, ASME, pp. 39-50, 1993.
- Gardner, B. K. and Bernhard, R. J., “A noise source identification technique using an inverse Helmholtz Integral Equation Method,” Journal of Vibration, Acoustics, Stress and Reliability in Design, 1988, Vol.110, 84-90.
- Bai, M. R., “Application of BEM (boundary element method)-based acoustic holography to radiation analysis of sound sources with arbitrarily shaped geometries”, J. Acoust. Soc. Am. 92(1), 533-549 (1992).
- Veronesi, W. A. and Maynard, J. D., “Digital holographic reconstruction of sources with arbitrarily shaped surfaces”, J. Acoust. Soc. Am. 85(2), 588-598 (1989).
- Kim, G. T. and Lee, B. H., “3-D Sound Source Reconstruction and Field Reproduction Using the Helmholtz Integral Equation”, Journal of Sound and Vibration, 136, pp. 245-261, 1990.
- Kim, B. K. and Ih, J. G., “On the reconstruction of the vibro-acoustic field over the surface enclosing an interior space using the boundary element method”, J. Acoust. Soc. Am. 100(5), 3003-3015 (1996).
- Raveendra, S. T., Gardner, B., Nejade A., and Sureshkumar, S., “An Integrated Experimental/ Numerical Noise Source Identification Technique”, Proceedings of the International Modal Analysis Conference (IMAC), pp. 1763-1768, February 2000.
- Raveendra, S. T. and Sureshkumar S., “Noise Source Identification in an Aircraft Using Nearfield Acoustical Holography”, Proceedings of the American Institute of Aeronautics and Astronautics Conference, AIAA 2000-2097, June 2000.
- Zhang, Z., Vlahopoulos, N., Raveendra, S. T., Allen, T., and Zhang, K. Y., “A computational acoustic field reconstruction process based on an indirect boundary element formulation”, J. Acoust. Soc. Am. 108(5), 2167-2178, 2000.
- Raveendra, S. T. and Zhang, Z. Identification of Turbomachinery noise sources using acoustical holography, Phase I SBIR Final Report submitted to NASA GRC, Comet Technology Corporation, 2004.
- Banerjee, P. I. Boundary Element Method in Engineering, McGraw Hill, 1992.
- Kirsch, A., An Introduction to the Mathematical Theory of Inverse Problems, Springer-Verlag, 1996.
- Kook, H., Davies P., and Bolton, J. S., Statistical properties of random sparse arrays, Journal of Sound and Vibration, 255(5), 819-848 (2002).