Hostname: page-component-76fb5796d-22dnz Total loading time: 0 Render date: 2024-04-26T07:14:42.723Z Has data issue: false hasContentIssue false

Acoustic boundary conditions at an impedance lining in inviscid shear flow

Published online by Cambridge University Press:  04 May 2016

Doran Khamis
Affiliation:
Department of Applied Mathematics and Theoretical Physics, University of Cambridge, Wilberforce Road, Cambridge CB3 0WA, UK
Edward James Brambley*
Affiliation:
Department of Applied Mathematics and Theoretical Physics, University of Cambridge, Wilberforce Road, Cambridge CB3 0WA, UK
*
Email address for correspondence: e.j.brambley@damtp.cam.ac.uk

Abstract

The accuracy of existing impedance boundary conditions is investigated, and new impedance boundary conditions are derived, for lined ducts with inviscid shear flow. The accuracy of the Ingard–Myers boundary condition is found to be poor. Matched asymptotic expansions are used to derive a boundary condition accurate to second order in the boundary layer thickness, which shows substantially increased accuracy for thin boundary layers when compared with both the Ingard–Myers boundary condition and its recent first-order correction. Closed-form approximate boundary conditions are also derived using a single Runge–Kutta step to solve an impedance Ricatti equation, leading to a boundary condition that performs reasonably even for thicker boundary layers. Surface modes and temporal stability are also investigated.

Type
Papers
Copyright
© 2016 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

Aurégan, Y. & Leroux, M. 2008 Experimental evidence of an instability over an impedance wall in a duct with flow. J. Sound Vib. 317, 432439.Google Scholar
Bers, A. 1983 Space–time evolution of plasma instabilities – absolute and convective. In Basic Plasma Physics (ed. Galeev, A. A. & Sudan, R. N.), Handbook of Plasma Physics, vol. 1, pp. 451517. North-Holland.Google Scholar
Boyer, G., Piot, E. & Brazier, J.-P. 2011 Theoretical investigation of hydrodynamic surface mode in a lined duct with sheared flow and comparison with experiment. J. Sound Vib. 330, 17931809.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. 2011a Acoustic implications of a thin viscous boundary layer over a compliant surface or permeable liner. J. Fluid Mech. 678, 348378.CrossRefGoogle Scholar
Brambley, E. J. 2011b Well-posed boundary condition for acoustic liners in straight ducts with flow. AIAA J. 49 (6), 12721282.Google Scholar
Brambley, E. J. 2013 Surface modes in sheared boundary layers over impedance linings. J. Sound Vib. 332, 37503767.Google Scholar
Brambley, E. J., Darau, M. & Rienstra, S. W. 2012 The critical layer in linear-shear boundary layers over acoustic linings. J. Fluid Mech. 710, 545568.Google Scholar
Brambley, E. J. & Peake, N. 2006 Classification of aeroacoustically relevant surface modes in cylindrical lined ducts. Wave Motion 43, 301310.CrossRefGoogle Scholar
Brambley, E. J. & Peake, N. 2008 Stability and acoustic scattering in a cylindrical thin shell containing compressible mean flow. J. Fluid Mech. 602, 403426.Google Scholar
Briggs, R. J. 1964 Electron-Stream Interaction with Plasmas. MIT Press.Google Scholar
Eversman, W. & Beckemeyer, R. J. 1972 Transmission of sound in ducts with thin shear layer – convergence to the uniform flow case. J. Acoust. Soc. Am. 52 (1B), 216220.CrossRefGoogle Scholar
Gabard, G. 2013 A comparison of impedance boundary conditions for flow acoustics. J. Sound Vib. 332 (4), 714724.Google Scholar
Gabard, G. & Brambley, E. J. 2014 A full discrete dispersion analysis of time-domain simulations of acoustic liners with flow. J. Comput. Phys. 273, 310326.CrossRefGoogle Scholar
Hairer, E., Nørsett, S. P. & Wanner, G. 1993 Solving Ordinary Differential Equations I: Nonstiff Problems. Springer.Google Scholar
Ingard, U. 1959 Influence of fluid motion past a plane boundary on sound reflection, absorption, and transmission. J. Acoust. Soc. Am. 31, 10351036.Google Scholar
Joubert, L.2010 Asymptotic approach for the mathematical and numerical analysis of the acoustic propagation in a strong shear flow. PhD thesis, École Polytechnique, Paris.Google Scholar
Khamis, D. & Brambley, E. J. 2015 The effective impedance of a finite-thickness viscothermal boundary layer over an acoustic lining. In 21st AIAA/CEAS Aeroacoustics Conference and Exhibit, American Institute of Aeronautics and Astronautics.Google Scholar
Koch, W. & Moehring, W. 1983 Eigensolutions for liners in uniform mean flow ducts. AIAA J. 21 (2), 200213.Google Scholar
Marx, D., Aurégan, Y., Bailliet, H. & Valiére, J.-C. 2010 PIV and LDV evidence of hydrodynamic instability over a liner in a duct with flow. J. Sound Vib. 329, 37983812.Google Scholar
McAlpine, A., Astley, R. J., Hii, V. J. T., Baker, N. J. & Kempton, A. J. 2006 Acoustic scattering by an axially-segmented turbofan inlet duct liner at supersonic fan speeds. J. Sound Vib. 294 (4–5), 780806.Google Scholar
Myers, M. K. 1980 On the acoustic boundary condition in the presence of flow. J. Sound Vib. 71 (3), 429434.Google Scholar
Myers, M. K. & Chuang, S. L. 1984 Uniform asymptotic approximations for duct acoustic modes in a thin boundary-layer flow. AIAA J. 22 (9), 12341241.Google Scholar
Pierce, A. D. 1994 Acoustics, 3rd edn. Acoustical Society of America.Google Scholar
Pridmore-Brown, D. C. 1958 Sound propagation in a fluid flowing through an attenuating duct. J. Fluid Mech. 4 (4), 393406.Google Scholar
Renou, Y. & Aurégan, Y. 2010 On a modified Myers boundary condition to match lined wall impedance deduced from several experimental methods in presence of a grazing flow. In 16th AIAA/CEAS Aeroacoustics Conference, American Institute of Aeronautics and Astronautics.Google Scholar
Renou, Y. & Aurégan, Y. 2011 Failure of the Ingard–Myers boundary condition for a lined duct: an experimental investigation. J. Acoust. Soc. Am. 130 (1), 5260.CrossRefGoogle ScholarPubMed
Rienstra, S. W. 2003 A classification of duct modes based on surface waves. Wave Motion 37 (2), 119135.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. & Vilenski, G. G. 2008 Spatial instability of boundary layer along impedance wall. In 14th AIAA/CEAS Aeroacoustics Conference (29th AIAA Aeroacoustics Conference), American Institute of Aeronautics and Astronautics.Google Scholar
Tam, C. K. W. & Morris, P. J. 1980 The radiation of sound by the instability waves of a compressible plane turbulent shear layer. J. Fluid Mech. 98 (2), 349381.Google Scholar
Tester, B. J. 1973a Some aspects of ‘sound’ attenuation in lined ducts containing inviscid mean flows with boundary layers. J. Sound Vib. 28, 217245.Google Scholar
Tester, B. J. 1973b The propagation and attenuation of sound in lined ducts containing uniform or plug flow. J. Sound Vib. 28 (2), 151203.Google Scholar
Vilenksi, G. G. & Rienstra, S. W. 2007 On hydrodynamic and acoustic modes in a ducted shear flow with wall lining. J. Fluid Mech. 583, 4570.Google Scholar