Scattering of Sound by Large Finite Geometries

Diffraction problems with finite geometries do not usually haveexact solutions and so asymptotic methods, which require a largeor small parameter, are employed to obtain approximate results.This paper presents a formal method for approximating the acousticpotential when the finite length in the geometry is large comparedto an acoustic wavelength. The method presented is exactly analogousto other approaches, including the modified Wiener-Hopf technique,but is advantageous because of its relative ease of use andapplicability to many problems. This is shown by using the methodon problems with resonances and complicated geometries.