Hostname: page-component-669899f699-chc8l Total loading time: 0 Render date: 2025-04-29T10:43:00.396Z Has data issue: false hasContentIssue false
  • English
  • Français

Acoustic scattering by a finite rigid plate with a poroelastic extension

Published online by Cambridge University Press:  24 February 2016

Lorna J. Ayton
Lorna J. Ayton*
Affiliation:
Department of Applied Mathematics and Theoretical Physics, University of Cambridge, Wilberforce Road, CB3 0WA, UK
*
†Email address for correspondence: [email protected]
Get access Rights & Permissions [Opens in a new window]

Abstract

The scattering of sound by a finite rigid plate with a finite poroelastic extension interacting with an unsteady acoustic source is investigated to determine the effects of porosity, elasticity and the length of the extension when compared to a purely rigid plate. The problem is solved using the Wiener–Hopf technique, and an approximate Wiener–Hopf factorisation process is implemented to yield reliable far-field results quickly. Importantly, finite chord-length effects are taken into account, principally the interaction of a rigid leading-edge acoustic field with a poroelastic trailing-edge acoustic field. The model presented discusses how the poroelastic trailing-edge property of owls’ wings could inspire quieter aeroacoustic designs in bladed systems such as wind turbines, and provides a framework for analysing the potential noise reduction of these designs.

JFM classification

Acoustics: Acoustics Acoustics: Aeroacoustics Acoustics: Noise control
Type
Papers
Information
Journal of Fluid Mechanics , Volume 791 , 25 March 2016 , pp. 414 - 438
Check for updates
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.)

Article purchase

Temporarily unavailable

References

Abrahams, I. D. 1983 Scattering of sound by an elastic plate with flow. J. Sound Vib. 89, 213–231.Google Scholar
Abrahams, I. D. 2000 The application of Padé approximants to Wiener–Hopf factorization. IMA J. Appl. Maths 65, 257–281.CrossRefGoogle Scholar
Ayton, L. J. & Peake, N. 2013 On high-frequency noise scattering by aerofoils in flow. J. Fluid Mech. 734, 144–182.Google Scholar
Barone, M. F.2011 Survey of techniques for reduction of wind turbine blade trailing edge noise. Sandia Tech. Rep. pp. SAND2011–5252.Google Scholar
Cavalieri, A. V. G., Wolf, W. R. & Jaworski, J. W. 2014 Acoustic scattering by finite poroelastic plates. In 20th AIAA/CEAS Aeroacoustics Conference, Atlanta.Google Scholar
Clark, I. A.2014. A study of bio-inspired canopies for the reduction of roughness noise. PhD thesis, Virginia Polytechnic Institute and State University.Google Scholar
Graham, R. R. 1934 The silent flight of owls. J. R. Aero. Soc. 38, 837–843.CrossRefGoogle Scholar
Haeri, S., Kim, J. W. & Joseph, P. 2015 On the mechanisms of noise reduction in aerofoil-turbulence interaction by using wavy leading edges. In 21st AIAA/CEAS Aeroacoustics Conference, Dallas, TX.Google Scholar
Howe, M. S. 1979 On the added mass of a perforated shell, with application to the generation of aerodynamic sound by a perforated trailing edge. Proc. R. Soc. Lond. A 365, 209–233.Google Scholar
Howe, M. S. 1991 Aerodynamic noise of a serrated trailing edge. J. Fluids Struct. 5, 33–45.Google Scholar
Howe, M. S. 1993 Structural and acoustic noise produced by turbulent flow over an elastic trailing edge. Proc. R. Soc. Lond. A 442, 533–554.Google Scholar
Howe, M. S. 1998 Acoustics of Fluid–Structure Interactions. Cambridge University Press.Google Scholar
Jaworski, J. W. & Peake, N. 2013 Aerodynamic noise from a poroelastic edge with implications for the silent flight of owls. J. Fluid Mech. 723, 456–479.CrossRefGoogle Scholar
Koegler, K. U., Herr, S. & Fisher, M.2009 Wind turbine blades with trailing edge serrations. US Patent App. 11/857,844.Google Scholar
Mathews, J. & Peake, N. 2015 Noise generation by turbulence interacting with an aerofoil with a serrated leading edge. In 21st AIAA/CEAS Aeroacoustics Conference, Dallas, TX.Google Scholar
Noble, B. 1958 Methods Based on the Wiener–Hopf Technique for the Solution of Partial Differential Equations. Pergamon.Google Scholar
Roger, M. & Moreau, S. 2005 Back-scattering correction and further extensions of Amiet’s trailing-edge noise model. Part 1: theory. J. Sound Vib. 286, 477–506.Google Scholar
Scott, J. F. M. 1992 Acoustic scattering by a finite elastic strip. Phil. Trans. R. Soc. Lond. 338, 145–167.Google Scholar
Timoshenko, S. P. & Woinowsky-Kreiger, S. 1959 Theory of Plates and Shells. McGraw-Hill.Google Scholar
Veitch, B. & Peake, N. 2008 Acoustic propagation and scattering in the exhaust flow from coaxial cylinders. J. Fluid Mech. 613, 275–307.Google Scholar