Analytical study of the effect of wave number on the performance of local absorbing boundary conditions for acoustic scattering

2004 ◽  
Vol 50 (1) ◽  
pp. 15-47 ◽  
Author(s):  
Isaac Harari ◽  
Rabia Djellouli
2000 ◽  
Author(s):  
Isaac Harari ◽  
Rabia Djellouli

Abstract The computation of exterior wave problems at low wave numbers can become prohibitively expensive when higher circumferential modes are significant. An analysis of the effect of wave number on scattering problems, with local absorbing boundary conditions specified on simple shapes as on-surface radiation conditions, provides guidelines for satisfactory performance. Excessive computational cost may be avoided for most practical applications.


1997 ◽  
Vol 05 (01) ◽  
pp. 117-136 ◽  
Author(s):  
Loukas F. Kallivokas ◽  
Aggelos Tsikas ◽  
Jacobo Bielak

We have recently developed absorbing boundary conditions for the three-dimensional scalar wave equation in full-space. Their applicability has been extended to half-space scattering problems where the scatterer is located near a pressure-free surface. A variational scheme was also proposed for coupling the structural acoustics equations with the absorbing boundary conditions. It was shown that the application of a Galerkin method on the variational form results in an attractive finite element scheme that, in a natural way, gives rise to a surface-only absorbing boundary element on the truncation boundary. The element — the finite element embodiment of a second-order absorbing boundary condition — is completely characterized by a pair of symmetric, frequency-independent damping and stiffness matrices, and is equally applicable to the transient and harmonic steady-state regimes. Previously, we had applied the methodology to problems involving scatterers of arbitrary geometry. In this paper, we validate our approach by comparing numerical results for rigid spherical scatterers submerged in a half-space, against a recently developed analytic solution.


AIAA Journal ◽  
1999 ◽  
Vol 37 ◽  
pp. 912-918
Author(s):  
M. E. Hayder ◽  
Fang Q. Hu ◽  
M. Y. Hussaini

2020 ◽  
Vol 66 (4) ◽  
pp. 773-793 ◽  
Author(s):  
Arman Shojaei ◽  
Alexander Hermann ◽  
Pablo Seleson ◽  
Christian J. Cyron

Abstract Diffusion-type problems in (nearly) unbounded domains play important roles in various fields of fluid dynamics, biology, and materials science. The aim of this paper is to construct accurate absorbing boundary conditions (ABCs) suitable for classical (local) as well as nonlocal peridynamic (PD) diffusion models. The main focus of the present study is on the PD diffusion formulation. The majority of the PD diffusion models proposed so far are applied to bounded domains only. In this study, we propose an effective way to handle unbounded domains both with PD and classical diffusion models. For the former, we employ a meshfree discretization, whereas for the latter the finite element method (FEM) is employed. The proposed ABCs are time-dependent and Dirichlet-type, making the approach easy to implement in the available models. The performance of the approach, in terms of accuracy and stability, is illustrated by numerical examples in 1D, 2D, and 3D.


1992 ◽  
Vol 40 (11) ◽  
pp. 2095-2099 ◽  
Author(s):  
J.A. Morente ◽  
J.A. Porti ◽  
M. Khalladi

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