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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: L.J.Ayton@damtp.cam.ac.uk
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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
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Copyright
© 2016 Cambridge University Press 

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