Fictitious Domain Methods for the Numerical Solution of Three-dimensional Acoustic Scattering Problems PDF Download

Author: Erkki Heikkola
Publisher:
ISBN: 9789513902407
Category :
Languages : en
Pages : 23

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Author:
Publisher:
ISBN:
Category : Mathematical statistics
Languages : en
Pages : 1402

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Author: Gary Cohen
Publisher: Springer Science & Business Media
ISBN: 3642558569
Category : Technology & Engineering
Languages : en
Pages : 923

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Book Description
This volume includes articles on the mathematical modeling and numerical simulation of various wave phenomena. For many years Waves 2003 and its five prior conferences have been an important forum for discussions on wave propagation. The topic is equally important for fundamental sciences, engineering, mathematics and, in particular, for industrial applications. Areas of specific interest are acoustics, electromagnetics, elasticity and related inverse and optimization problems. This book gives an extensive overview of recent developments in a very active field of scientific computing.

Author: Yuxiang Liu
Publisher:
ISBN:
Category :
Languages : en
Pages : 342

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Book Description
"The control of waves using periodic structures is crucial for modern optical, electromagnetic and acoustic devices such as diffraction gratings, filters, photonic crystals, solar cells, sensors, and absorbers. We present a high-order accurate boundarybased numerical solver for three-dimensional (3D) frequency-domain scattering from a doubly-periodic grating of obstacles. We focus on the case of axisymmetric objects, and handle both acoustic and electromagnetic cases. We combine the method of fundamental solutions (MFS) with a new periodizing scheme, using various fast algorithms such as the fast multiple method and the so-called \skeletonization". Our scheme has exponential convergence for analytic shapes and avoids singular quadratures, periodic Green's functions, and lattice sums. Furthermore, the convergence rate of our scheme is unaffected by resonances within obstacles. The periodizing scheme is also independent of the complexity of the objects and the frequency can reach 13[lambda] x 13[lambda] x 13[lambda] in each periodic unit, which covers the vast majority of scattering problems in practice; meanwhile, the solver can achieve 10 digits of accuracy, takes less than 1 hour of computational time, and requires less than 6GB of RAM space. We also propose a way to efficiently solve scattering problems on boundaries with corners using the MFS to achieve 10 digits of accuracy for a range of corner angles. Also, we can observe exponential convergence as the number of unknowns increases for corner problems. Lastly, we develop and test the use of a recently-developed fast direct solver for least squares problems to solve high frequency scattering problems on general (non-axisymmetric) smooth objects using the MFS."

Author: Acoustical Society of America
Publisher:
ISBN:
Category : Acoustical engineering
Languages : en
Pages : 1350

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Author: Jingzhi Li
Publisher: Springer Nature
ISBN: 9819937728
Category : Science
Languages : en
Pages : 373

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Book Description
This book highlights the latest developments on the numerical methods for inverse scattering problems associated with acoustic, electromagnetic, and elastic waves. Inverse scattering problems are concerned with identifying unknown or inaccessible objects by wave probing data, which makes possible many industrial and engineering applications including radar and sonar, medical imaging, nondestructive testing, remote sensing, and geophysical exploration. The mathematical study of inverse scattering problems is an active field of research. This book presents a comprehensive and unified mathematical treatment of various inverse scattering problems mainly from a numerical reconstruction perspective. It highlights the collaborative research outputs by the two groups of the authors yet surveys and reviews many existing results by global researchers in the literature. The book consists of three parts respectively corresponding to the studies on acoustic, electromagnetic, and elastic scattering problems. In each part, the authors start with in-depth theoretical and computational treatments of the forward scattering problems and then discuss various numerical reconstruction schemes for the associated inverse scattering problems in different scenarios of practical interest. In addition, the authors provide an overview of the existing results in the literature by other researchers. This book can serve as a handy reference for researchers or practitioners who are working on or implementing inverse scattering methods. It can also serve as a graduate textbook for research students who are interested in working on numerical algorithms for inverse scattering problems.

Author: Claude Bourrely
Publisher: World Scientific
ISBN: 981461887X
Category :
Languages : en
Pages : 374

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Contents:Light Scattering Problems in Astrophysics (J M Perrin)Surface Integral Operators and their Use in Acoustics and Electromagnetics (A Berthon)Acoustic Diffraction by Slender Bodies of Arbitrary Shape (M Tran-Van-Nhieu)High and Low Energy Approximations for the Electromagnetic Scattering by Irregular Objects (B Torresani)Electromagnetic Scattering and Mutual Interactions Between Closely Spaced Spheroids (J Dalmas & R Deleuil)Acoustical Imaging of 2D Fluid Targets Buried in a Half Space: A Diffraction Tomography Approach Using Line-Sources Insonification (B Duchene et al)Contribution of Radar Polarimetry in Radar Target Discrimination. The “Poincaré Planisphere”: a New Representation Method (E Pottier)Electromagnetic and Acoustic Waves in Random Media: from Propagation to Anderson Localization (B Souillard)Weak Disorder: Homogeneisation Method and Propagation (C Bardos)Coherent Propagation of Surface Acoustic Waves in Quasi-Periodic and Random Arrays of Grooves (D Sornette et al)On Asymptotic Behaviour of Waves States in Random Media (F Bentosela & R Rodriguez)A Study of Acoustic Transmission of Transient Signal in a Inhomogeneous Medium with the Help of a Wavelet Transform. Application to an Air-Water Plane Interface (G Saracco & Ph Tchamitchian)Three-Dimensional Impedance Scattering Theory (P Sabatier)Survey of Optimization Algorithms Applied to Inverse Problems (A Roger)A Linearized Inverse Problem: Acoustic Impedance Tomography of Biological Media (J P Lefebvre)and others Readership: Electrical engineers and mathematicians.

Author: Andrew Tristan Peplow
Publisher:
ISBN:
Category :
Languages : en
Pages : 118

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This thesis is concerned with the mathematical and numerical modelling of sound propagation over infinite surfaces in two and three-dimensions. In particular we consider the prediction, in a homogeneous medium, of sound propagation from a source in a cutting out onto flat surrounding ground, and scattering by an infinite rigid obstacle in three dimensions. In Chapter 2 a boundary integral formulation for the two-dimensional Helmholtz equation in a locally-perturbed half-plane with impedance boundary condition is developed to calculate sound propagation out of a cutting onto the surrounding terrain. A main result in this chapter is to show that the integral equation is uniquely solvable. A simple but robust boundary element method is developed and experimental convergence rates and numerical predictions are presented. Chapter 3 is concerned with the asymptotic behaviour of solutions at infinity to multidimensional second kind integral equations. A general second kind integral equation set on an infinite cylindrical surface is analysed in Chapter 4. Under certain conditions it is shown that an approximate solution, obtained by solving an integral equation on a finite cylindrical surface of length 2a, converges to the original solution, as a tends to infinity. Uniform stability and convergence results for a piecewise constant boundary element method for the truncated equations are also obtained. A boundary integral equation, which models three-dimensional acoustic radiation from an infinite rigid cylinder, illustrating the results of Chapters 3 and 4, is examined in Chapter 5.

Author: Erdogan Alkan
Publisher: Morgan & Claypool Publishers
ISBN: 1627051465
Category : Technology & Engineering
Languages : en
Pages : 131

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This book presents the application of the overlapping grids approach to solve chiral material problems using the FDFD method. Due to the two grids being used in the technique, we will name this method as Double-Grid Finite Difference Frequency-Domain (DG-FDFD) method. As a result of this new approach the electric and magnetic field components are defined at every node in the computation space. Thus, there is no need to perform averaging during the calculations as in the aforementioned FDFD technique [16]. We formulate general 3D frequency-domain numerical methods based on double-grid (DG-FDFD) approach for general bianisotropic materials. The validity of the derived formulations for different scattering problems has been shown by comparing the obtained results to exact and other solutions obtained using different numerical methods. Table of Contents: Introduction / Chiral Media / Basics of the Finite-Difference Frequency-Domain (FDFD) Method / The Double-Grid Finite-Difference Frequency-Domain (DG-FDFD) Method for Bianisotropic Medium / Scattering FromThree Dimensional Chiral Structures / ImprovingTime and Memory Efficiencies of FDFD Methods / Conclusions / Appendix A: Notations / Appendix B: Near to Far FieldTransformation

Author: F. El Dabaghi
Publisher: Oxford University Press, USA
ISBN:
Category : Mathematics
Languages : en
Pages : 416

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This book was written in response to the increasing interest in the high frequency numerical solution of Maxwell's equations. Research activity in this area has been stimulated by requirements for greater precision in radar cross-section calculations, particularly for geometries with lowobservability; however there are also a growing number of applications in bio-electromagnetism and electromagnetic compatibility. It is hoped that these proceedings will be of interest both to specialists in this area as well as to others simply looking for a guide to recent developments.