Download or read book Time Domain Boundary Integral Equation Methods in Acoustics Heat Diffusion and Electromagnetism written by Tianyu Qiu and published by . This book was released on 2016 with total page 126 pages. Available in PDF, EPUB and Kindle. Book excerpt: This thesis analyzes the discretization error induced by the Convolution Quadrature Galerkin method in seeking the numerical solution to time domain boundary integral equations arising in the problem of acoustic wave scattering by penetrable obstacles, electromagnetic wave scattering by a perfect electric conductor and heat conduction in the presence of a bounded inclusion. There are two sources of the numerical error: the error between the exact solution and spatial semidiscrete solution, and the error between the spatial semidiscrete solution and fully discrete solution. In the spatial semidiscrete error analysis, we fit the problem into the framework of the strongly continuous semigroup theory and obtain an error estimate sharper than that attainable by the traditional Laplace domain approach. For the full discrete error analysis, we try to apply the functional calculus theory to achieve a pure time domain approach with some success. Several numerical experiments are provided to validate the theoretical results.

Download or read book Retarded Potentials and Time Domain Boundary Integral Equations written by Francisco-Javier Sayas and published by Springer. This book was released on 2016-04-12 with total page 251 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book offers a thorough and self-contained exposition of the mathematics of time-domain boundary integral equations associated to the wave equation, including applications to scattering of acoustic and elastic waves. The book offers two different approaches for the analysis of these integral equations, including a systematic treatment of their numerical discretization using Galerkin (Boundary Element) methods in the space variables and Convolution Quadrature in the time variable. The first approach follows classical work started in the late eighties, based on Laplace transforms estimates. This approach has been refined and made more accessible by tailoring the necessary mathematical tools, avoiding an excess of generality. A second approach contains a novel point of view that the author and some of his collaborators have been developing in recent years, using the semigroup theory of evolution equations to obtain improved results. The extension to electromagnetic waves is explained in one of the appendices.

Download or read book Time Domain Boundary Integral Equations Analysis written by Amir Geranmayeh and published by Sudwestdeutscher Verlag Fur Hochschulschriften AG. This book was released on 2011-01 with total page 208 pages. Available in PDF, EPUB and Kindle. Book excerpt: The present research study mainly involves a survey of diverse time-domain boundary element methods that can be used to numerically solve the retarded potential integral equations. The aim is to address the late-time stability, accuracy, and computational complexity concerns in time-domain surface integral equation approaches. The study generally targets the transient electromagnetic scattering of three- dimensional perfectly conducting bodies. Efficient algorithms are developed to numerically solve the electric, magnetic, and combined field integral equations for the unknown induced surface current. The algorithms are mainly categorized into three major discretization schemes, namely the marching-on- in-time, the marching-on-in-order, and the convolution quadrature methods or finite difference delay modeling. Possible choices of space-time integration are examined and the results are compared with the finite integration technique's solution. The outcome is applied to the non- dispersive modeling of the field propagation in particle accelerator structures, when travelling bunches of charged particles passes through the beam line elements.

Download or read book Boundary Integral Equation Methods in Eigenvalue Problems of Elastodynamics and Thin Plates written by M. Kitahara and published by Elsevier. This book was released on 2014-12-03 with total page 292 pages. Available in PDF, EPUB and Kindle. Book excerpt: The boundary integral equation (BIE) method has been used more and more in the last 20 years for solving various engineering problems. It has important advantages over other techniques for numerical treatment of a wide class of boundary value problems and is now regarded as an indispensable tool for potential problems, electromagnetism problems, heat transfer, fluid flow, elastostatics, stress concentration and fracture problems, geomechanical problems, and steady-state and transient electrodynamics.In this book, the author gives a complete, thorough and detailed survey of the method. It provides the only self-contained description of the method and fills a gap in the literature. No-one seriously interested in eigenvalue problems of elasticity or in the boundary integral equation method can afford not to read this book. Research workers, practising engineers and students will all find much of benefit to them.Contents: Introduction. Part I. Applications of Boundary Integral Equation Methods to Eigenvalue Problems of Elastodynamics. Fundamentals of BIE Methods for Elastodynamics. Formulation of BIEs for Steady-State Elastodynamics. Formulation of Eigenvalue Problems by the BIEs. Analytical Treatment of Integral Equations for Circular and Annular Domains. Numerical Procedures for Eigenvalue Problems. Numerical Analysis of Eigenvalue Problems in Antiplane Elastodynamics. Numerical Analysis of Eigenvalue Problems in Elastodynamics. Appendix: Dominant mode analysis around caverns in a semi-infinite domain. Part II. Applications of BIE Methods to Eigenvalue Problems of Thin Plates. Fundamentals of BIE Methods for Thin Plates. Formulation of BIEs for Thin Plates and Eigenvalue Problems. Numerical Analysis of Eigenvalue Problems in Plate Problems. Indexes.

Download or read book Modelling Simulation and Data Analysis in Acoustical Problems written by Claudio Guarnaccia and published by MDPI. This book was released on 2020-06-23 with total page 584 pages. Available in PDF, EPUB and Kindle. Book excerpt: Modelling and simulation in acoustics is currently gaining importance. In fact, with the development and improvement of innovative computational techniques and with the growing need for predictive models, an impressive boost has been observed in several research and application areas, such as noise control, indoor acoustics, and industrial applications. This led us to the proposal of a special issue about “Modelling, Simulation and Data Analysis in Acoustical Problems”, as we believe in the importance of these topics in modern acoustics’ studies. In total, 81 papers were submitted and 33 of them were published, with an acceptance rate of 37.5%. According to the number of papers submitted, it can be affirmed that this is a trending topic in the scientific and academic community and this special issue will try to provide a future reference for the research that will be developed in coming years.

Download or read book The Nystrom Method in Electromagnetics written by Mei Song Tong and published by John Wiley & Sons. This book was released on 2020-06-29 with total page 528 pages. Available in PDF, EPUB and Kindle. Book excerpt: A comprehensive, step-by-step reference to the Nyström Method for solving Electromagnetic problems using integral equations Computational electromagnetics studies the numerical methods or techniques that solve electromagnetic problems by computer programming. Currently, there are mainly three numerical methods for electromagnetic problems: the finite-difference time-domain (FDTD), finite element method (FEM), and integral equation methods (IEMs). In the IEMs, the method of moments (MoM) is the most widely used method, but much attention is being paid to the Nyström method as another IEM, because it possesses some unique merits which the MoM lacks. This book focuses on that method—providing information on everything that students and professionals working in the field need to know. Written by the top researchers in electromagnetics, this complete reference book is a consolidation of advances made in the use of the Nyström method for solving electromagnetic integral equations. It begins by introducing the fundamentals of the electromagnetic theory and computational electromagnetics, before proceeding to illustrate the advantages unique to the Nyström method through rigorous worked out examples and equations. Key topics include quadrature rules, singularity treatment techniques, applications to conducting and penetrable media, multiphysics electromagnetic problems, time-domain integral equations, inverse scattering problems and incorporation with multilevel fast multiple algorithm. Systematically introduces the fundamental principles, equations, and advantages of the Nyström method for solving electromagnetic problems Features the unique benefits of using the Nyström method through numerical comparisons with other numerical and analytical methods Covers a broad range of application examples that will point the way for future research The Nystrom Method in Electromagnetics is ideal for graduate students, senior undergraduates, and researchers studying engineering electromagnetics, computational methods, and applied mathematics. Practicing engineers and other industry professionals working in engineering electromagnetics and engineering mathematics will also find it to be incredibly helpful.

Download or read book Inverse Acoustic and Electromagnetic Scattering Theory written by David Colton and published by Springer Nature. This book was released on 2019-11-06 with total page 518 pages. Available in PDF, EPUB and Kindle. Book excerpt: The inverse scattering problem is central to many areas of science and technology such as radar, sonar, medical imaging, geophysical exploration and nondestructive testing. This book is devoted to the mathematical and numerical analysis of the inverse scattering problem for acoustic and electromagnetic waves. In this fourth edition, a number of significant additions have been made including a new chapter on transmission eigenvalues and a new section on the impedance boundary condition where particular attention has been made to the generalized impedance boundary condition and to nonlocal impedance boundary conditions. Brief discussions on the generalized linear sampling method, the method of recursive linearization, anisotropic media and the use of target signatures in inverse scattering theory have also been added.

Download or read book Boundary Integral Equation Methods for Screen Problems in Acoustic and Electromagnetic Aerospace Research written by H. Schippers and published by . This book was released on 1997 with total page 44 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Integral Equation Methods for Evolutionary PDE written by Lehel Banjai and published by Springer. This book was released on 2023-11-10 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book provides a comprehensive analysis of time domain boundary integral equations and their discretisation by convolution quadrature and the boundary element method. Properties of convolution quadrature, based on both linear multistep and Runge–Kutta methods, are explained in detail, always with wave propagation problems in mind. Main algorithms for implementing the discrete schemes are described and illustrated by short Matlab codes; translation to other languages can be found on the accompanying GitHub page. The codes are used to present numerous numerical examples to give the reader a feeling for the qualitative behaviour of the discrete schemes in practice. Applications to acoustic and electromagnetic scattering are described with an emphasis on the acoustic case where the fully discrete schemes for sound-soft and sound-hard scattering are developed and analysed in detail. A strength of the book is that more advanced applications such as linear and non-linear impedance boundary conditions and FEM/BEM coupling are also covered. While the focus is on wave scattering, a chapter on parabolic problems is included which also covers the relevant fast and oblivious algorithms. Finally, a brief description of data sparse techniques and modified convolution quadrature methods completes the book. Suitable for graduate students and above, this book is essentially self-contained, with background in mathematical analysis listed in the appendix along with other useful facts. Although not strictly necessary, some familiarity with boundary integral equations for steady state problems is desirable.

Download or read book The Boundary Element Method in Acoustics written by Stephen Kirkup and published by Stephen Kirkup. This book was released on 1998 with total page 136 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Integral Equation Methods for Electromagnetic and Elastic Waves written by Weng Cho Chew and published by Morgan & Claypool Publishers. This book was released on 2009 with total page 259 pages. Available in PDF, EPUB and Kindle. Book excerpt: Integral Equation Methods for Electromagnetic and Elastic Waves is an outgrowth of several years of work. There have been no recent books on integral equation methods. There are books written on integral equations, but either they have been around for a while, or they were written by mathematicians. Much of the knowledge in integral equation methods still resides in journal papers. With this book, important relevant knowledge for integral equations are consolidated in one place and researchers need only read the pertinent chapters in this book to gain important knowledge needed for integral equation research. Also, learning the fundamentals of linear elastic wave theory does not require a quantum leap for electromagnetic practitioners. Integral equation methods have been around for several decades, and their introduction to electromagnetics has been due to the seminal works of Richmond and Harrington in the 1960s. There was a surge in the interest in this topic in the 1980s (notably the work of Wilton and his coworkers) due to increased computing power. The interest in this area was on the wane when it was demonstrated that differential equation methods, with their sparse matrices, can solve many problems more efficiently than integral equation methods. Recently, due to the advent of fast algorithms, there has been a revival in integral equation methods in electromagnetics. Much of our work in recent years has been in fast algorithms for integral equations, which prompted our interest in integral equation methods. While previously, only tens of thousands of unknowns could be solved by integral equation methods, now, tens of millions of unknowns can be solved with fast algorithms. This has prompted new enthusiasm in integral equation methods. Table of Contents: Introduction to Computational Electromagnetics / Linear Vector Space, Reciprocity, and Energy Conservation / Introduction to Integral Equations / Integral Equations for Penetrable Objects / Low-Frequency Problems in Integral Equations / Dyadic Green's Function for Layered Media and Integral Equations / Fast Inhomogeneous Plane Wave Algorithm for Layered Media / Electromagnetic Wave versus Elastic Wave / Glossary of Acronyms

Download or read book Boundary Integral Equation Methods for Screen Problems in Acoustic and Electromagnetic Aerospace Research written by H. Schippers and published by . This book was released on 1999 with total page 44 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Integral Equation Techniques in Transient Electromagnetics written by Dragan Poljak and published by Computational Mechanics. This book was released on 2003 with total page 272 pages. Available in PDF, EPUB and Kindle. Book excerpt: Transient electromagnetic phenomena can be treated in two ways, either using direct time domain modeling or frequency domain analysis applying the inverse Fourier transform. Both approaches are important since each has distinct advantages depending on the situation or the application.

Download or read book Integral Equation Methods for Evolutionary PDE written by Lehel Banjai and published by Springer Nature. This book was released on 2022-11-08 with total page 283 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book provides a comprehensive analysis of time domain boundary integral equations and their discretisation by convolution quadrature and the boundary element method. Properties of convolution quadrature, based on both linear multistep and Runge–Kutta methods, are explained in detail, always with wave propagation problems in mind. Main algorithms for implementing the discrete schemes are described and illustrated by short Matlab codes; translation to other languages can be found on the accompanying GitHub page. The codes are used to present numerous numerical examples to give the reader a feeling for the qualitative behaviour of the discrete schemes in practice. Applications to acoustic and electromagnetic scattering are described with an emphasis on the acoustic case where the fully discrete schemes for sound-soft and sound-hard scattering are developed and analysed in detail. A strength of the book is that more advanced applications such as linear and non-linear impedance boundary conditions and FEM/BEM coupling are also covered. While the focus is on wave scattering, a chapter on parabolic problems is included which also covers the relevant fast and oblivious algorithms. Finally, a brief description of data sparse techniques and modified convolution quadrature methods completes the book. Suitable for graduate students and above, this book is essentially self-contained, with background in mathematical analysis listed in the appendix along with other useful facts. Although not strictly necessary, some familiarity with boundary integral equations for steady state problems is desirable.

Download or read book Adaptive Methods for Time Domain Boundary Integral Equations for Acoustic Scattering written by Matthias Gläfke and published by . This book was released on 2012 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: This thesis is concerned with the study of transient scattering of acoustic waves by an obstacle in an infinite domain, where the scattered wave is represented in terms of time domain boundary layer potentials. The problem of finding the unknown solution of the scattering problem is thus reduced to the problem of finding the unknown density of the time domain boundary layer operators on the obstacle's boundary, subject to the boundary data of the known incident wave. Using a Galerkin approach, the unknown density is replaced by a piecewise polynomial approximation, the coefficients of which can be found by solving a linear system. The entries of the system matrix of this linear system involve, for the case of a two dimensional scattering problem, integrals over four dimensional space-time manifolds. An accurate computation of these integrals is crucial for the stability of this method. Using piecewise polynomials of low order, the two temporal integrals can be evaluated analytically, leading to kernel functions for the spatial integrals with complicated domains of piecewise support. These spatial kernel functions are generalised into a class of admissible kernel functions. A quadrature scheme for the approximation of the two dimensional spatial integrals with admissible kernel functions is presented and proven to converge exponentially by using the theory of countably normed spaces. A priori error estimates for the Galerkin approximation scheme are recalled, enhanced and discussed. In particular, the scattered wave's energy is studied as an alternative error measure. The numerical schemes are presented in such a way that allows the use of non-uniform meshes in space and time, in order to be used with adaptive methods that are based on a posteriori error indicators and which modify the computational domain according to the values of these error indicators. The theoretical analysis of these schemes demands the study of generalised mapping properties of time domain boundary layer potentials and integral operators, analogously to the well known results for elliptic problems. These mapping properties are shown for both two and three space dimensions. Using the generalised mapping properties, three types of a posteriori error estimators are adopted from the literature on elliptic problems and studied within the context of the two dimensional transient problem. Some comments on the three dimensional case are also given. Advantages and disadvantages of each of these a posteriori error estimates are discussed and compared to the a priori error estimates. The thesis concludes with the presentation of two adaptive schemes for the two dimensional scattering problem and some corresponding numerical experiments.

Download or read book Boundary Elements Theory and Applications written by John T. Katsikadelis and published by Elsevier. This book was released on 2002-05-28 with total page 351 pages. Available in PDF, EPUB and Kindle. Book excerpt: The author's ambition for this publication was to make BEM accessible to the student as well as to the professional engineer. For this reason, his maintask was to organize and present the material in such a way so that the book becomes "user-friendly" and easy to comprehend, taking into account only the mathematics and mechanics to which students have been exposed during their undergraduate studies. This effort led to an innovative, in many aspects, way of presentingBEM, including the derivation of fundamental solutions, the integral representation of the solutions and the boundary integral equations for various governing differentialequations in a simple way minimizing a recourse to mathematics with which the student is not familiar. The indicial and tensorial notations, though they facilitate the author's work and allow to borrow ready to use expressions from the literature, have been avoided in the present book. Nevertheless, all the necessary preliminary mathematical concepts have been included in order to make the book complete and self-sufficient. Throughout the book, every concept is followed by example problems, which have been worked out in detail and with all the necessary clarifications. Furthermore, each chapter of the book is enriched with problems-to-solve. These problems serve a threefold purpose. Some of them are simple and aim at applying and better understanding the presented theory, some others are more difficult and aim at extending the theory to special cases requiring a deeper understanding of the concepts, and others are small projects which serve the purpose of familiarizing the student with BEM programming and the programs contained in the CD-ROM. The latter class of problems is very important as it helps students to comprehend the usefulness and effectiveness of the method by solving real-life engineering problems. Through these problems students realize that the BEM is a powerful computational tool and not an alternative theoretical approach for dealing with physical problems. My experience in teaching BEM shows that this is the students' most favorite type of problems. They are delighted to solve them, since they integrate their knowledge and make them feel confident in mastering BEM. The CD-ROM which accompanies the book contains the source codes of all the computer programs developed in the book, so that the student or the engineer can use them for the solution of a broad class of problems. Among them are general potential problems, problems of torsion, thermal conductivity,deflection of membranes and plates, flow of incompressible fluids, flow through porous media, in isotropic or anisotropic, homogeneous or composite bodies, as well as plane elastostatic problems in simply or multiply connected domains. As one can readily find out from the variety of the applications, the book is useful for engineers of all disciplines. The author is hopeful that the present book will introduce the reader to BEM in an easy, smooth and pleasant way and also contribute to itsdissemination as a modern robust computational tool for solving engineering problems.

Download or read book Integral Operator Methods in the Theory of Wave Propagation and Heat Conduction written by David L. Colton and published by . This book was released on 1977 with total page 68 pages. Available in PDF, EPUB and Kindle. Book excerpt: Until recently the method of integral operators as initiated by S. Bergman and I.N. Vekua has been restricted to the case of elliptic equations and the investigation of steady state phenomena. In these lectures we survey the recent developments on the use of integral operators to investigate equations associated with evolutionary phenomena, in particular parabolic equations, pseudoparabolic equations, and the reduced wave equation in a stratified medium. The topics discussed are transformation operators for partial differential equations, reflection principles and their application, the propagation of radio waves around the earth, the propagation of acoustic waves in a spherically stratified medium, low frequency approximations to acoustic scattering problems in a spherically stratified medium, heat conduction in two temperatures, inverse problems in the theory of heat conduction, and Runge's theorem for parabolic equations. Open problems are given at the end of each section. (Author).