Abstract:On s'intéresse au calcul du champélectromagnétique diffracté par un obstacle conducteur recouvert d'un matériau hétérogène. Onétudie une méthode numérique consistantà coupler une approximation paŕ eléments finis de volumes avec des potentiels retardés de surface. Plusieurs formulations variationnelles espace-temps sont présentées. Onétablit des résultats de stabilité et de convergence pour la méthode proposée.
“…The basic idea underlying the proposed numerical scheme is to preserve the symmetry properties and the energy estimates valid for the continuous weak formulation. Its essential elements are: (1) finite elements for space discretization and an implicit Newmark finite differences scheme for time discretization in the FEM interval 1 ; (2) collocation technique for the first integral equation in (5) and Galerkin method for the second one (which in this case plays the role of the hyper-singular equation).…”
“…The basic idea underlying the proposed numerical scheme is to preserve the symmetry properties and the energy estimates valid for the continuous weak formulation. Its essential elements are: (1) finite elements for space discretization and an implicit Newmark finite differences scheme for time discretization in the FEM interval 1 ; (2) collocation technique for the first integral equation in (5) and Galerkin method for the second one (which in this case plays the role of the hyper-singular equation).…”
“…Important discretization techniques include Galerkin methods based on space-time variational formulations (cf. [3,30,36,2,1,16,33]) and methods based on bandlimited interpolation and extrapolation (cf. [41,39,40,42]).…”
In this paper we consider time-dependent electromagnetic scattering problems from conducting objects. We discretize the time-domain electric field integral equation using RungeKutta convolution quadrature in time and a Galerkin method in space. We analyze the involved operators in the Laplace domain and obtain convergence results for the fully discrete scheme. Numerical experiments indicate the sharpness of the theoretical estimates.
“…The papers [2,3] study the numerical approximation of the single-and double-layer retarded acoustic potentials in three dimensions. Extensions of these results are many (see [1,4,16] and the references in the review [15]), all of them dealing with Galerkin methods. For the collocation method applied to the single-layer retarded potential, see [14].…”
In this paper we address several theoretical questions related to the numerical approximation of the scattering of acoustic waves in two or three dimensions by penetrable non-homogeneous obstacles using convolution quadrature (CQ) techniques for the time variable and coupled boundary element method/finite element method for the space variable. The applicability of CQ to waves requires polynomial type bounds for operators related to the operator − s 2 in the right half complex plane. We propose a new systematic way of dealing with this problem, both at the continuous and semidiscrete-in-space cases. We apply the technique to three different situations: scattering by a group of sound-soft and -hard obstacles, by homogeneous and non-homogeneous obstacles.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.