Traveling wave excitation sources for FEM analysis of scattering in acoustic waveguide

This paper proposes use of traveling wave type excitation sources for the scattering analysis of acoustic waveguides using the finite element method (FEM). This technique allows to generate only one particular mode selectively. Scattering behavior at arbitrary boundaries can be evaluated accurately and quickly in frequency domain. After describing and demonstrating its operation mechanism in detail, this technique is applied to two cases. First, wave scattering properties are discussed at the end of a two-dimensional closed waveguide. Then the technique is applied to a three-dimensional open waveguide including periodic gratings. The results reveal effectiveness of this technique.