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Theoretical model of acoustic scattering from a flat plate with serrations

Published online by Cambridge University Press:  18 April 2017

Xun Huang Open the ORCID record for Xun Huang [Opens in a new window]
Xun Huang*
Affiliation:
State Key Laboratory of Turbulence and Complex Systems, Aeronautics and Astronautics, College of Engineering, Peking University, Beijing, 100871, China Department of Mechanical and Aerospace Engineering, The Hong Kong University of Science and Technology, Hong Kong, China
*
†Email addresses for correspondence: huangxun@pku.edu.cn, huangxun@ust.hk
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Abstract

A theoretical model is proposed in this work to study the scattering of sound waves from a serrated flat plat in the presence of a uniform flow, which is of both scientific significance and practical importance. The key contribution is the analytic and rigorous description of the scattering from the laterally periodic serrations by incorporating Fourier series expansions and the Wiener–Hopf method, which collectively give a closed-form analytical solution. To validate and demonstrate the model, a couple of test cases with some representative sinusoidal- and sawtooth-shaped serrations are studied by comparing with a commercial finite element solver. The comparisons show quite good agreement for various set-ups. The subsequent parametric studies further demonstrate the efficiency of the model and the effect of the serrations for noise control. Overall, the proposed theoretical model should be able to assist in studies of low-noise aerofoils and the silent flying capabilities of owls.

JFM classification

Acoustics: Acoustics Acoustics: Aeroacoustics
Type
Papers
Information
Journal of Fluid Mechanics , Volume 819 , 25 May 2017 , pp. 228 - 257
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Copyright
© 2017 Cambridge University Press 

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