Gaussian beam summation in shallow waveguides
2008 (English)In: Wave motion, ISSN 0165-2125, Vol. 45, no 4, 445-456 p.Article in journal (Refereed) Published
The complex beam parameter a controls the beamwidth and the curvature of the wavefront of a Gaussian beam. Here some strategies for choosing a are analysed for a shallow cylindrically symmetric waveguide and examplified by three choices of a used in the calculation of synthetic impulse responses by Gaussian beam summation.
The geometry of the shallow waveguide puts a restriction on the feasible width of the beams, since beams that are too wide cause problems with end effects in the summation. Best results in the numerical examples are observed when choosing epsilon to give plane wavefronts and narrow beams at the points contributing to the field, so that the end effects are negligible.
The expansion of a point source into beams for launch-angle-dependent epsilon is shown to agree with the commonly used expansion, corresponding to launch-angle-independent epsilon.
Place, publisher, year, edition, pages
2008. Vol. 45, no 4, 445-456 p.
Acoustics; Caustics; Gaussian beam; Shadow zone; Waveguide; Acoustic waves; Circular waveguides; Computational methods; Numerical methods; Wavefronts; Beamwidth; Gaussian beam summation; Shallow waveguide; Gaussian beams; Acoustic waves; Circular waveguides; Computational methods; Gaussian beams; Numerical methods; Wavefronts; acoustic wave; electromagnetic wave; Gaussian method; numerical model; point source; wave propagation
Fluid Mechanics and Acoustics
IdentifiersURN: urn:nbn:se:kth:diva-7793DOI: 10.1016/j.wavemoti.2007.09.003ISI: 000255418300006ScopusID: 2-s2.0-40649124533OAI: oai:DiVA.org:kth-7793DiVA: diva2:12921
QC 20100819. Uppdaterad från In press till Published 20100819.2007-12-102007-12-102010-08-19Bibliographically approved