scholarly journals Wavenumber-Explicit Bounds in Time-Harmonic Acoustic Scattering

2014 ◽  
Vol 46 (4) ◽  
pp. 2987-3024 ◽  
Author(s):  
E. A. Spence
Keyword(s):  
Acoustic Scattering ◽  
Time Harmonic ◽  
Explicit Bounds

scholarly journals Bayesian approach to inverse time-harmonic acoustic scattering with phaseless far-field data

2020 ◽  
Vol 36 (6) ◽  
pp. 065012
Author(s):  
Zhipeng Yang ◽  
Xinping Gui ◽  
Ju Ming ◽  
Guanghui Hu
Keyword(s):  
Bayesian Approach ◽  
Field Data ◽  
Acoustic Scattering ◽  
Far Field ◽  
Time Harmonic

scholarly journals AN APPROXIMATE BOUNDARY INTEGRAL METHOD FOR ACOUSTIC SCATTERING IN SHALLOW OCEANS

1993 ◽  
Vol 01 (01) ◽  
pp. 61-75 ◽  
Author(s):  
YONGZHI XU ◽  
YI YAN
Keyword(s):  
Integral Equation ◽  
Wave Scattering ◽  
Integral Method ◽  
Acoustic Scattering ◽  
Quadrature Rule ◽  
Boundary Integral ◽  
Boundary Integral Method ◽  
Acoustic Wave Scattering ◽  
Sea Bottom ◽  
Time Harmonic

The problem of a time-harmonic acoustic wave scattering from a cylindrical object in shallow oceans is solved by an approximate boundary integral method. In the method we employ a Green's function of the Helmholtz equation with sound soft sea level and sound hard sea bottom conditions, and reformulate the problem into a boundary integral equation on the surface of the scattering object. The kernel of the integral equation is given by an infinite series, and is approximated by an appropriate truncation. The integral equation is then fully discretized by applying a quadrature rule. The method has an O(N−3) rate of convergence. Various numerical examples are presented.

Time-Harmonic Acoustic Scattering in a Complex Flow: A Full Coupling Between Acoustics and Hydrodynamics

2012 ◽  
Vol 11 (2) ◽  
pp. 555-572 ◽  
Author(s):  
A.S.Bonnet-Ben Dhia ◽  
J.F. Mercier ◽  
F. Millot ◽  
S. Pernet ◽  
E. Peynaud
Keyword(s):  
Complex Geometry ◽  
Acoustic Scattering ◽  
Mathematical Framework ◽  
Perfectly Matched Layers ◽  
Mean Flow ◽  
Complex Flow ◽  
Numerical Result ◽  
Convection Equation ◽  
Time Harmonic ◽  
Artificial Boundaries

AbstractFor the numerical simulation of time harmonic acoustic scattering in a complex geometry, in presence of an arbitrary mean flow, the main difficulty is the coexistence and the coupling of two very different phenomena: acoustic propagation and convection of vortices. We consider a linearized formulation coupling an augmented Galbrun equation (for the perturbation of displacement) with a time harmonic convection equation (for the vortices). We first establish the well-posedness of this time harmonic convection equation in the appropriate mathematical framework. Then the complete problem, with Perfectly Matched Layers at the artificial boundaries, is proved to be coercive + compact, and a hybrid numerical method for the solution is proposed, coupling finite elements for the Galbrun equation and a Discontinuous Galerkin scheme for the convection equation. Finally a 2D numerical result shows the efficiency of the method.

scholarly journals Time-Harmonic Acoustic Scattering from Locally Perturbed Half-Planes

2018 ◽  
Vol 78 (5) ◽  
pp. 2672-2691 ◽  
Author(s):  
Gang Bao ◽  
Guanghui Hu ◽  
Tao Yin
Keyword(s):  
Acoustic Scattering ◽  
Time Harmonic

scholarly journals An Efficient and Stable Spectral-Element Method for Acoustic Scattering by an Obstacle

2013 ◽  
Vol 3 (3) ◽  
pp. 190-208
Author(s):  
Jing An ◽  
Jie Shen
Keyword(s):  
Spectral Element Method ◽  
Perturbation Technique ◽  
Scattering Problem ◽  
Acoustic Scattering ◽  
Spectral Element ◽  
Boundary Perturbation ◽  
Sound Waves ◽  
Time Harmonic ◽  
Accuracy And Stability ◽  
Element Method

AbstractA spectral-element method is developed to solve the scattering problem for time-harmonic sound waves due to an obstacle in an homogeneous compressible fluid. The method is based on a boundary perturbation technique coupled with an efficient spectral-element solver. Extensive numerical results are presented, in order to show the accuracy and stability of the method.

Time harmonic acoustic scattering in anisotropic media

2005 ◽  
Vol 28 (12) ◽  
pp. 1383-1401 ◽  
Author(s):  
G. Dassios ◽  
K. S. Karadima
Keyword(s):  
Acoustic Scattering ◽  
Anisotropic Media ◽  
Time Harmonic

scholarly journals Boundary element methods for acoustic scattering by fractal screens

2021 ◽  
Vol 147 (4) ◽  
pp. 785-837 ◽  
Author(s):  
Simon N. Chandler-Wilde ◽  
David P. Hewett ◽  
Andrea Moiola ◽  
Jeanne Besson
Keyword(s):  
Boundary Element ◽  
Boundary Integral Equations ◽  
Sufficient Conditions ◽  
Acoustic Scattering ◽  
Boundary Integral ◽  
Boundary Element Methods ◽  
Fractal Boundary ◽  
Time Harmonic ◽  
Simulation Strategy ◽  
Theoretical Results

AbstractWe study boundary element methods for time-harmonic scattering in $${\mathbb {R}}^n$$ R n ($$n=2,3$$ n = 2 , 3 ) by a fractal planar screen, assumed to be a non-empty bounded subset $$\Gamma $$ Γ of the hyperplane $$\Gamma _\infty ={\mathbb {R}}^{n-1}\times \{0\}$$ Γ ∞ = R n - 1 × { 0 } . We consider two distinct cases: (i) $$\Gamma $$ Γ is a relatively open subset of $$\Gamma _\infty $$ Γ ∞ with fractal boundary (e.g. the interior of the Koch snowflake in the case $$n=3$$ n = 3 ); (ii) $$\Gamma $$ Γ is a compact fractal subset of $$\Gamma _\infty $$ Γ ∞ with empty interior (e.g. the Sierpinski triangle in the case $$n=3$$ n = 3 ). In both cases our numerical simulation strategy involves approximating the fractal screen $$\Gamma $$ Γ by a sequence of smoother “prefractal” screens, for which we compute the scattered field using boundary element methods that discretise the associated first kind boundary integral equations. We prove sufficient conditions on the mesh sizes guaranteeing convergence to the limiting fractal solution, using the framework of Mosco convergence. We also provide numerical examples illustrating our theoretical results.

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