A frequency-independent boundary element method for scattering by two-dimensional screens and apertures

Hewett, D. P., Langdon, S. and Chandler-Wilde, S. N. ORCID: https://orcid.org/0000-0003-0578-1283 (2015) A frequency-independent boundary element method for scattering by two-dimensional screens and apertures. IMA Journal of Numerical Analysis, 35 (4). pp. 1698-1728. ISSN 1464-3642 doi: 10.1093/imanum/dru043

Abstract/Summary

We propose and analyse a hybrid numerical–asymptotic hp boundary element method (BEM) for time-harmonic scattering of an incident plane wave by an arbitrary collinear array of sound-soft two-dimensional screens. Our method uses an approximation space enriched with oscillatory basis functions, chosen to capture the high-frequency asymptotics of the solution. We provide a rigorous frequency-explicit error analysis which proves that the method converges exponentially as the number of degrees of freedom N increases, and that to achieve any desired accuracy it is sufficient to increase N in proportion to the square of the logarithm of the frequency as the frequency increases (standard BEMs require N to increase at least linearly with frequency to retain accuracy). Our numerical results suggest that fixed accuracy can in fact be achieved at arbitrarily high frequencies with a frequency-independent computational cost, when the oscillatory integrals required for implementation are computed using Filon quadrature. We also show how our method can be applied to the complementary ‘breakwater’ problem of propagation through an aperture in an infinite sound-hard screen.

Item Type	Article
URI	https://reading-clone.eprints-hosting.org/id/eprint/38264
Identification Number/DOI	10.1093/imanum/dru043
Refereed	Yes
Divisions	Science > School of Mathematical, Physical and Computational Sciences > Department of Mathematics and Statistics
Publisher	Oxford University Press
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