Hostname: page-component-848d4c4894-pjpqr Total loading time: 0 Render date: 2024-07-01T23:20:01.152Z Has data issue: false hasContentIssue false

Theoretical model of scattering from flow ducts with semi-infinite axial liner splices

Published online by Cambridge University Press:  30 November 2015

Xin Liu
Affiliation:
State Key Laboratory of Turbulence and Complex Systems, College of Engineering, Peking University, Beijing, China
Hanbo Jiang
Affiliation:
State Key Laboratory of Turbulence and Complex Systems, College of Engineering, Peking University, Beijing, China
Xun Huang*
Affiliation:
State Key Laboratory of Turbulence and Complex Systems, College of Engineering, Peking University, Beijing, China Department of Mechanical and Aerospace Engineering, Hong Kong University of Science and Technology, Clear Water Bay, Kowloon, Hong Kong SAR, China
Shiyi Chen
Affiliation:
State Key Laboratory of Turbulence and Complex Systems, College of Engineering, Peking University, Beijing, China
*
Email addresses for correspondence: huangxun@pku.edu.cn, huangxun@ust.hk

Abstract

In this paper we present a theoretical model to study sound scattering from flow ducts with a semi-infinite lining surface covered by some equally spaced rigid splices, which is of practical importance in the development of silent aeroengines. The key contribution of our work is the analytical and rigorous description of axial liner splices by incorporating Fourier series expansion and the Wiener–Hopf method. In particular, we describe periodic variations of the semi-infinite lining surface by using Fourier series that accurately represent the layout of rigid splices in the circumferential direction. The associated matrix kernel involves a constant matrix and a diagonal matrix. The latter consists of a series of typical scalar kernels. A closed-form solution is then obtained by using standard routines of Wiener–Hopf factorisation for scalar kernels. A couple of appropriate approximations, such as numerical truncations of infinite Fourier series, have to be adopted in the implementation of this theoretical model, which is validated by comparing favorably with numerical solutions from a commercial acoustic solver. Finally, several numerical test cases are performed to demonstrate this theoretical model. It can be seen that the proposed theoretical model helps to illuminate the essential acoustic effect jointly imposed by axial and circumferential hard–soft interfaces.

Type
Papers
Copyright
© 2015 Cambridge University Press 

Access options

Get access to the full version of this content by using one of the access options below. (Log in options will check for institutional or personal access. Content may require purchase if you do not have access.)

References

Bi, W. P., Pagneux, V., Lafarge, D. & Aurégan, Y. 2006 Modelling of sound propagation in a non-uniform lined duct using a multi-modal propagation method. J. Sound Vib. 289, 10911111.CrossRefGoogle Scholar
Bi, W. P., Pagneux, V., Lafarge, D. & Aurégan, Y. 2007 Characteristics of penalty mode scattering by rigid splices in lined ducts. J. Acoust. Soc. Am. 121 (3), 13031312.Google Scholar
Brambley, E. J. 2009 Fundamental problems with the model of uniform flow over acoustic linings. J. Sound Vib. 322, 10261037.Google Scholar
Brambley, E. J., Davis, A. M. J. & Peake, N. 2012 Eigenmodes of lined flow ducts with rigid splices. J. Fluid Mech. 690, 399425.CrossRefGoogle Scholar
Duta, M. C. & Giles, M. B. 2006 A three-dimensional hybrid finite element/spectral analysis of noise radiation from turbofan inlets. J. Sound Vib. 296, 623642.Google Scholar
Elnady, T., Boden, H. & Glav, R. 2001 Application of the point matching method to model circumferentially segmented non-locally reacting liners. AIAA Paper 20012202.Google Scholar
Fuller, C. R. 1984 Propagation and radiation of sound from flanged circular ducts with circumferentially varying wall admittances, I: Semi-infinite ducts. J. Sound Vib. 93, 321340.Google Scholar
Gabard, G. & Astley, R. J. 2006 Theoretical model for sound radiation from annular jet pipes: far- and near-field solutions. J. Fluid Mech. 549, 315341.CrossRefGoogle Scholar
Huang, X., Zhong, S. Y. & Liu, X. 2014 Acoustic invisibility in turbulent fluids by optimised cloaking. J. Fluid Mech. 749, 460477.CrossRefGoogle Scholar
Ingard, U. 1959 Influence of fluid motion past a plane boundary on sound reflection, absorption, and transmission. J. Acoust. Soc. Am. 31 (7), 10351036.CrossRefGoogle Scholar
Koch, W. & Möhring, W. 1983 Eigensolutions for liners in uniform mean flow ducts. AIAA J. 21 (2), 200213.Google Scholar
Liu, X., Huang, X. & Zhang, X. 2014 Stability analysis and design of time-domain acoustic impedance boundary conditions for lined duct with mean flow. J. Acoust. Soc. Am. 136 (5), 24412452.Google Scholar
McAlpine, A. & Wright, M. C. M. 2006 Acoustic scattering by a spliced turbofan inlet duct liner at supersonic fan speeds. J. Sound Vib. 292 (3–5), 911934.Google Scholar
Munt, R. M. 1977 The interaction of sound with a subsonic jet issuing from a semi-infinite cylindrical pipe. J. Fluid Mech. 83, 609640.Google Scholar
Myers, M. K. 1980 On the acoustic boundary condition in the presence of flow. J. Sound Vib. 71 (3), 429434.CrossRefGoogle Scholar
Noble, B. 1958 Methods Based on the Wiener–Hopf Technique for the Solution of Partial Differential Equations. Pergamon.Google Scholar
Quinn, M. C. & Howe, M. S. 1984 On the production and absorption of sound by lossless liners in the presence of mean flow. J. Sound Vib. 97 (1), 19.Google Scholar
Regan, B. & Eaton, J. 1999 Modelling the influence of acoustic liner non-uniformities on duct modes. J. Sound Vib. 219, 859879.Google Scholar
Rienstra, S. W. 1981 Sound diffraction at a trailing edge. J. Fluid Mech. 108, 443460.Google Scholar
Rienstra, S. W. 1984 Acoustic radiation from a semi-infinite annular duct in a uniform subsonic mean flow. J. Sound Vib. 94 (2), 267288.Google Scholar
Rienstra, S. W. 2003a A classification of duct modes based on surface waves. Wave Motion 37 (2), 119135.Google Scholar
Rienstra, S. W. 2003b Sound propagation in slowly varying lined flow ducts of arbitrary cross-section. J. Fluid Mech. 495, 157173.CrossRefGoogle Scholar
Rienstra, S. W. 2007 Acoustic scattering at a hard–soft lining transition in a flow duct. J. Engng Maths 59, 451475.Google Scholar
Rienstra, S. W. & Darau, M. 2011 Boundary-layer thickness effects of the hydrodynamic instability along an impedance wall. J. Fluid Mech. 671, 559573.Google Scholar
Rienstra, S. W. & Eversman, W. 2001 A numerical comparison between the multiple-scales and finite-element solution for sound propagation in lined flow ducts. J. Fluid Mech. 437, 367384.Google Scholar
Tam, C. K., Ju, H. & Chien, E. W. 2008 Scattering of acoustic duct modes by axial liner splices. J. Sound Vib. 310, 10141035.CrossRefGoogle Scholar
Tester, B. J. 1973 Some aspects of sound attenuation in lined ducts containing inviscid mean flows with boundary layers. J. Sound Vib. 28 (2), 217245.Google Scholar
Tester, B. J., Powles, C. J., Baker, N. J. & Kempton, A. J. 2006 Scattering of sound by liner splices: a Kirchhoff model with numerical verification. AIAA J. 44 (9), 20092017.Google Scholar
Tyler, J. M. & Sofrin, T. G.1962 Axial flow compressor noise studies. Tech. Rep. SAE Technical Paper.Google Scholar
Veitch, B. & Peake, N. 2008 Acoustic propagation and scattering in the exhaust flow from coaxial cylinders. J. Fluid Mech. 613, 275307.Google Scholar
Yang, B. & Wang, T. Q. 2008 Investigation of the influence of liner hard-splices on duct radiation/propagation and mode scattering. J. Sound Vib. 315, 10161034.Google Scholar