TWO-DIMENSIONAL APPROXIMATE LOCAL DtN BOUNDARY CONDITIONS FOR ELLIPTICAL-SHAPED BOUNDARIES

Autor: Barucq, Hélène, Djellouli, Rabia, Saint-Guirons, Anne-Gaëlle
Přispěvatelé: Laboratoire de Mathématiques appliquées de Pau (LMAP), Centre National de la Recherche Scientifique (CNRS)-Université de Pau et des Pays de l'Adour (UPPA), Advanced 3D Numerical Modeling in Geophysics (Magique 3D), Laboratoire de Mathématiques et de leurs Applications [Pau] (LMAP), Université de Pau et des Pays de l'Adour (UPPA)-Centre National de la Recherche Scientifique (CNRS)-Université de Pau et des Pays de l'Adour (UPPA)-Centre National de la Recherche Scientifique (CNRS)-Inria Bordeaux - Sud-Ouest, Institut National de Recherche en Informatique et en Automatique (Inria)-Institut National de Recherche en Informatique et en Automatique (Inria), Department of Mathematics [CSUN], California State University [Northridge] (CSUN), Michael Taroudakis, Panagiotis Papadakis, Équipe Associée Magic, Université de Pau et des Pays de l'Adour (UPPA)-Centre National de la Recherche Scientifique (CNRS)
Jazyk: angličtina
Rok vydání: 2007
Předmět:
Zdroj: International Conference on Theoretical and Computational Acoustics
International Conference on Theoretical and Computational Acoustics, Jul 2007, Heraklion, Greece
Popis: International audience; We propose a new class of approximate local DtN boundary conditions to be applied on elliptical-shaped exterior boundaries when solving acoustic scattering problems by elongated obstacles. These conditions are : (a) exact for the first modes, (b) easy to implement and to parallelize, (c) compatible with the local structure of the computational finite element scheme, and (d) applicable to exterior elliptical-shaped boundaries that are more suitable in terms of cost-effectiveness for surrounding elongated scatterers. We investigate analytically and numerically the effect of the frequency regime and the slenderness of the boundary on the accuracy of these conditions. We also compare their performance to the second order absorbing boundary condition (BGT2) designed by Bayliss, Gunzburger and Turkel when expressed in elliptical coordinates. The analysis reveals that, in the low frequency regime, the new second order DtN condition (DtN2) retains a good level of accuracy regardless of the slenderness of the boundary. In addition, the DtN2 boundary condition outperforms the BGT2 condition. Such superiority is clearly noticeable for large eccentricity values.
Databáze: OpenAIRE