An immersed boundary computational model for acoustic scattering problems with complex geometries

2012 ◽  
Vol 132 (5) ◽  
pp. 3190-3199 ◽  
Author(s):  
Xiaofeng Sun ◽  
Yongsong Jiang ◽  
An Liang ◽  
Xiaodong Jing
Keyword(s):  
Computational Model ◽  
Acoustic Scattering ◽  
Immersed Boundary ◽  
Complex Geometries ◽  
Scattering Problems ◽  
Acoustic Scattering Problems

A Study of Three-Dimensional Acoustic Scattering by Arbitrary Distribution Multibodies Using Extended Immersed Boundary Method

2014 ◽  
Vol 136 (3) ◽  
Author(s):  
Yongsong Jiang ◽  
Xiaoyu Wang ◽  
Xiaodong Jing ◽  
Xiaofeng Sun
Keyword(s):  
Boundary Condition ◽  
Computational Model ◽  
Acoustic Field ◽  
Three Dimensional ◽  
Acoustic Scattering ◽  
Impedance Boundary Condition ◽  
Immersed Boundary ◽  
Complex Geometries ◽  
Impedance Boundary ◽  
Wall Boundary Conditions

A three-dimensional computational model for acoustic scattering with complex geometries is presented, which employs the immersed boundary technique to deal with the effect of both hard and soft wall boundary conditions on the acoustic fields. In this numerical model, the acoustic field is solved on uniform Cartesian grids, together with simple triangle meshes to partition the immersed body surface. A direct force at the Lagrangian points is calculated from an influence matrix system, and then spreads to the neighboring Cartesian grid points to make the acoustic field satisfy the required boundary condition. This method applies a uniform stencil on the whole domain except at the computational boundary, which has the benefit of low dispersion and dissipation errors of the used scheme. The method has been used to simulate two benchmark problems to validate its effectiveness and good agreements with the analytical solutions are achieved. No matter how complex the geometries are, single body or multibodies, complex geometries do not pose any difficulty in this model. Furthermore, a simple implementation of time-domain impedance boundary condition is reported and demonstrates the versatility of the computational model.

Adaptivity and Three Dimensional Hierarchical Boundary Elements for Rigid Acoustic Scattering Problems

1995 ◽  
Author(s):  
Steven J. Newhouse ◽  
Ian C. Mathews
Keyword(s):  
Boundary Element ◽  
Acoustic Analysis ◽  
Three Dimensional ◽  
Acoustic Scattering ◽  
Error Estimator ◽  
Infinite Domain ◽  
Scattering Problems ◽  
Effective Form ◽  
Mesh Density ◽  
Acoustic Scattering Problems

Abstract The boundary element method is an established numerical tool for the analysis of acoustic pressure fields in an infinite domain. There is currently no well established method of estimating the surface pressure error distribution for an arbitrary three dimensional body. Hierarchical shape functions have been used as a highly effective form of p refinement in many finite and boundary element applications. Their ability to be used as an error estimator in acoustic analysis has never been fully exploited. This paper studies the influence of mesh density and interpolation order on several acoustic scattering problems. A hierarchical error estimator is implemented and its effectiveness verified against the spherical problem. A coarse cylindrical mesh is then refined using the new error estimator until the solution has converged. The effectiveness of this analysis is shown by comparing the error indicators derived during the analysis to the solution generated from a very fine cylindrical mesh.

Newton-Like Method for Solving Inverse Obstacle Acoustic Scattering Problems

2000 ◽  
Author(s):  
Rabia Djellouli ◽  
Charbel Farhat ◽  
Radek Tezaur
Keyword(s):  
Acoustic Scattering ◽  
Numerical Procedure ◽  
Decomposition Methods ◽  
Computationally Efficient ◽  
Scattering Problems ◽  
Absorbing Boundary ◽  
Element Discretization ◽  
Jacobian Matrices ◽  
Fast Solution ◽  
Acoustic Scattering Problems

Abstract A Newton-like method is designed for determining the shape or sought-after shape modifications of a scatterer from the knowledge of acoustic far-field patterns at a given number of observation points. This method distinguishes itself from existing numerical procedures by the following features: (a) exact Jacobian matrices for the linearized problems rather than approximate ones, (b) a fast numerical procedure for computing these Jacobian matrices, (c) a computationally efficient absorbing boundary condition for the finite element discretization, and (d) a numerically scalable domain decomposition methods for the fast solution of high-frequency direct acoustic scattering problems.

Marching schemes for inverse acoustic scattering problems

2005 ◽  
Vol 100 (4) ◽  
pp. 697-710 ◽  
Author(s):  
Frank Natterer ◽  
Frank Wübbeling
Keyword(s):  
Acoustic Scattering ◽  
Scattering Problems ◽  
Acoustic Scattering Problems
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