On the efficient representation of the half-space impedance Green's function for the Helmholtz equation

Research output: Contribution to journalArticle

Abstract

A classical problem in acoustic (and electromagnetic) scattering concerns the evaluation of the Green's function for the Helmholtz equation subject to impedance boundary conditions on a half-space. The two principal approaches used for representing this Green's function are the Sommerfeld integral and the (closely related) method of complex images. The former is extremely efficient when the source is at some distance from the half-space boundary, but involves an unwieldy range of integration as the source gets closer and closer. Complex image-based methods, on the other hand, can be quite efficient when the source is close to the boundary, but they do not easily permit the use of the superposition principle since the selection of complex image locations depends on both the source and the target. We have developed a new, hybrid representation which uses a finite number of real images (dependent only on the source location) coupled with a rapidly converging Sommerfeld-like integral. While our method applies in both two and three dimensions, we restrict the detailed analysis and numerical experiments here to the two-dimensional case.

Original languageEnglish (US)
Pages (from-to)1-13
Number of pages13
JournalWave Motion
Volume51
Issue number1
DOIs
StatePublished - Jan 2014

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Helmholtz equations
half spaces
Green's functions
impedance
acoustic scattering
electromagnetic scattering
boundary conditions
evaluation

Keywords

  • Green's function
  • Half-space
  • Helmholtz
  • Impedance
  • Layered media
  • Sommerfeld integral

ASJC Scopus subject areas

  • Physics and Astronomy(all)

Cite this

On the efficient representation of the half-space impedance Green's function for the Helmholtz equation. / O'Neil, Michael; Greengard, Leslie; Pataki, Andras.

In: Wave Motion, Vol. 51, No. 1, 01.2014, p. 1-13.

Research output: Contribution to journalArticle

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