A coupled modal-finite element method for the wave propagation modeling in irregular open waveguides
Résumé
In modeling the wave propagation within a street canyon, a particular attention must be paid to the description of both the multiple reflections of the wave on the building façades, and the radiation in the free space above the street. The street canyon being considered as an open waveguide with a discontinuously varying cross-section, a coupled modal-FE formulation is proposed to solve the threedimensional wave equation within. The originally open configuration-the street canyon open in the sky above-is artificially turned into a close waveguiding structure by using Perfectly Matched Layers (PML) that truncate the infinite sky without introducing numerical reflection. Then the eigenmodes of the resulting waveguide are determined by a FEM computation in the cross-section. The eigensolutions can finally be used in a multimodal formulation of the wave propagation along the canyon, given its geometry and the end conditions at its extremities : initial field condition at the entrance and radiation condition at the output.
Domaines
Acoustique [physics.class-ph]Origine | Fichiers produits par l'(les) auteur(s) |
---|