English
Related papers

Related papers: FEM-BEM mortar coupling for the Helmholtz problem …

200 papers

Transport and mixing properties of aperiodic flows are crucial to a dynamical analysis of the flow, and often have to be carried out with limited information. Finite-time coherent sets are regions of the flow that minimally mix with the…

Dynamical Systems · Mathematics 2018-02-12 Gary Froyland , Oliver Junge

We consider fourth order singularly perturbed boundary value problems with two small parameters, and the approximation of their solution by the $hp$ version of the Finite Element Method on the {\emph{Spectral Boundary Layer}} mesh from…

Numerical Analysis · Mathematics 2020-08-06 C. Xenophontos , S. Franz , I. Sykopetritou

Isogeometric analysis with the boundary element method (IGABEM) has recently gained interest. In this paper, the approximability of IGABEM on 3D acoustic scattering problems will be investigated and a new improved BeTSSi submarine will be…

Numerical Analysis · Mathematics 2022-04-21 Jon Vegard Venås , Trond Kvamsdal

We consider wave scattering from a system of highly contrasting resonators with time-modulated material parameters. In this setting, the wave equation reduces to a system of coupled Helmholtz equations that models the scattering problem. We…

Mathematical Physics · Physics 2024-01-05 Habib Ammari , Jinghao Cao , Erik Orvehed Hiltunen , Liora Rueff

We discuss the stability of homonuclear and heteronuclear mixtures of 3He and 4He atoms in the metastable 2^3S_1 state (He*) and predict positions and widths of Feshbach resonances by using the Asymptotic Bound-state Model (ABM). All…

Quantum Gases · Physics 2010-10-29 M. R. Goosen , T. G. Tiecke , W. Vassen , S. J. J. M. F. Kokkelmans

We present a complete analytical derivation of the equations used for stationary and nonstationary wave systems regarding resonant sound transmission and reflection described by the phenomenological Coupled-Mode Theory. We calculate the…

Classical Physics · Physics 2018-06-11 Theodoros T. Koutserimpas , Romain Fleury

In this paper we propose and analyse a hybrid numerical-asymptotic boundary element method for the solution of problems of high frequency acoustic scattering by a class of sound-soft nonconvex polygons. The approximation space is enriched…

Numerical Analysis · Mathematics 2014-01-14 David P. Hewett , Simon N. Chandler-Wilde , Stephen Langdon , Ashley Twigger

In this paper, we consider inverse time-harmonic acoustic and electromagnetic scattering from locally perturbed rough surfaces in three dimensions. The scattering interface is supposed to be the graph of a Lipschitz continuous function with…

Analysis of PDEs · Mathematics 2018-12-24 Yu Zhao , Guanghui Hu , Baoqiang Yan

Consider the wave propagation in a two-layered medium consisting of a homogeneous compressible air or fluid on top of a homogeneous isotropic elastic solid. The interface between the two layers is assumed to be an unbounded rough surface.…

Analysis of PDEs · Mathematics 2016-08-22 Yixian Gao , Peijun Li , Bo Zhang

Consider the electromagnetic scattering of a time-harmonic plane wave by an open cavity which is embedded in a perfectly electrically conducting infinite ground plane. This paper is concerned with the numerical solutions of the transverse…

Numerical Analysis · Mathematics 2021-04-07 Yanli Chen , Peijun Li , Xiaokai Yuan

Space-time materials are obtained by modulating a physical medium with a traveling-wave perturbation of one or several of its constitutive parameters, such as the density or the bulk modulus in the case of acoustic materials. When this…

Materials Science · Physics 2026-02-10 J. Galiana , J. Redondo , R. Picó , V. J. Sánchez-Morcillo

This article initiates the study of space-time adaptive mesh refinements for time-dependent boundary element formulations of wave equations. Based on error indicators of residual type, we formulate an adaptive boundary element procedure for…

Numerical Analysis · Mathematics 2025-11-07 Alessandra Aimi , Giulia Di Credico , Heiko Gimperlein , Chiara Guardasoni

We experimentally investigate four-wave mixing (FWM) of matter waves in two geometric configurations in $^{39}$K Bose-Einstein condensates with the atomic interaction tuned via Feshbach resonances. For one configuration with the single-spin…

The coaxial wire method is a common and appreciated technique to assess the beam coupling impedance of an accelerator element from scattering parameters. Nevertheless, the results obtained from wire measurements could be inaccurate due to…

Accelerator Physics · Physics 2024-06-17 Antuono Chiara , Zannini Carlo , Mostacci Andrea , Migliorati Mauro

A coupled boundary spectral element method (BSEM) and spectral element method (SEM) formulation for the propagation of small-amplitude water waves over variable bathymetries is presented in this work. The wave model is based on the…

Numerical Analysis · Mathematics 2025-02-04 Antonio Cerrato , Luis Rodríguez-Tembleque , José A. González , M. H. Ferri Aliabadi

This article is concerned with the time-harmonic electromagnetic (EM) scattering from a generic inhomogeneous medium. It is shown that if there is a right corner on the support of the medium, then it scatters every pair of incident EM…

Analysis of PDEs · Mathematics 2016-11-15 Hongyu Liu , Jingni Xiao

This paper is concerned with three-dimensional acoustic wave scattering in two-layer media, where the two homogeneous layers are separated by a locally perturbed plane featuring an axially symmetric perturbation. A fast novel boundary…

Numerical Analysis · Mathematics 2024-12-17 Hangya Wang , Wangtao Lu

We analyze a non-symmetric coupling of interior penalty discontinuous Galerkin and boundary element methods in two and three dimensions. Main results are discrete coercivity of the method, and thus unique solvability, and quasi-optimal…

Numerical Analysis · Mathematics 2011-11-11 Norbert Heuer , Francisco-Javier Sayas

We propose a fully $ \textit{ab initio} $ approach to predicting thermal attenuation in elastic helium atom scattering amplitudes, validated through strong agreement with experiments on Nb(100) and (3$\times$1)-O/Nb(100) surfaces. Our…

Materials Science · Physics 2024-12-17 Cristóbal Méndez , C. J. Thompson , M. F. Van Duinen , S. J. Sibener , Tomás A. Arias

Acoustic dampers are efficient and cost-effective means for suppressing thermoacoustic instabilities in combustion chambers. However, their design and the choice of their purging air mass flow is a challenging task, when one aims at…

Applied Physics · Physics 2019-02-20 Claire Bourquard , Nicolas Noiray