K-Space Formulation of the Electromagnetic Scattering Problem
K-Space Formulation of the Electromagnetic Scattering Problem

Author: Norbert N. Bojarski

Publisher:

Published: 1971

Total Pages: 216

ISBN-13:

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The Electromagnetic Scattering problem is solved by means of a k-space formulation of the Electromagnetic Field equations, thereby replacing the conventional integral equation formulation of the scattering problem by a set of two algebraic equations in two unknowns in two spaces (the constitutive equation being an algebraic equation in x-space). These equations are solved by an iterative method executed with the aid of Fast Fourier Transform (FFT) algorithm connecting the two spaces, requiring very simple zero order initial approximations. Since algebraic and FFT equations are used, the number of arithmetic multiply-add operations and storage allocations required for a numerical solution is reduced from the order of N squared (for solving the matrix equations resulting from the conventional integral equations) to the order of N log(sub 2)N (where N is the number of data points required for the specification of the scatterer). The advantage gained in speed and storage is thus of the order of N/log(sub 2)N and N respectively. This method is thus considerably more efficient, and permits exact numerical solutions for much larger scatterers, than possible with the conventional matrix method. (Author).

K-Space Formulation of the Two-Dimensional Electromagnetic Scattering Problem
K-Space Formulation of the Two-Dimensional Electromagnetic Scattering Problem

Author: Charles H Krueger (Jr)

Publisher:

Published: 1973

Total Pages: 115

ISBN-13:

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The Air Force has become increasingly interested in the numerical solution of electromagnetic scattering and radiation problems as a means of reducing the cost and time associated with the experimental solution of such problems. In the frequency range where body dimensions are comparable to the wavelength of the illuminating electromagnetic energy, it has been found that moment methods provide satisfactory numerical solutions to these problems. However, as the body dimensions become larger than, say two or three wavelengths, the computation time and computer memory size associated with moment methods become prohibitive. The method of solution described in the report is designed to significantly reduce both computation time and memory size required for moment method calculations. (Author).

Theory and Computation of Electromagnetic Fields
Theory and Computation of Electromagnetic Fields

Author: Jian-Ming Jin

Publisher: John Wiley & Sons

Published: 2015-08-10

Total Pages: 744

ISBN-13: 111910808X

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Reviews the fundamental concepts behind the theory and computation of electromagnetic fields The book is divided in two parts. The first part covers both fundamental theories (such as vector analysis, Maxwell’s equations, boundary condition, and transmission line theory) and advanced topics (such as wave transformation, addition theorems, and fields in layered media) in order to benefit students at all levels. The second part of the book covers the major computational methods for numerical analysis of electromagnetic fields for engineering applications. These methods include the three fundamental approaches for numerical analysis of electromagnetic fields: the finite difference method (the finite difference time-domain method in particular), the finite element method, and the integral equation-based moment method. The second part also examines fast algorithms for solving integral equations and hybrid techniques that combine different numerical methods to seek more efficient solutions of complicated electromagnetic problems. Theory and Computation of Electromagnetic Fields, Second Edition: Provides the foundation necessary for graduate students to learn and understand more advanced topics Discusses electromagnetic analysis in rectangular, cylindrical and spherical coordinates Covers computational electromagnetics in both frequency and time domains Includes new and updated homework problems and examples Theory and Computation of Electromagnetic Fields, Second Edition is written for advanced undergraduate and graduate level electrical engineering students. This book can also be used as a reference for professional engineers interested in learning about analysis and computation skills.

Finite Element Method Electromagnetics
Finite Element Method Electromagnetics

Author: John L. Volakis

Publisher: John Wiley & Sons

Published: 1998-06-15

Total Pages: 364

ISBN-13: 9780780334250

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Employed in a large number of commercial electromagnetic simulation packages, the finite element method is one of the most popular and well-established numerical techniques in engineering. This book covers the theory, development, implementation, and application of the finite element method and its hybrid versions to electromagnetics. FINITE ELEMENT METHOD FOR ELECTROMAGNETICS begins with a step-by-step textbook presentation of the finite method and its variations then goes on to provide up-to-date coverage of three dimensional formulations and modern applications to open and closed domain problems. Worked out examples are included to aid the reader with the fine features of the method and the implementation of its hybridization with other techniques for a robust simulation of large scale radiation and scattering. The crucial treatment of local boundary conditions is carefully worked out in several stages in the book. Sponsored by: IEEE Antennas and Propagation Society.

Solution of Superlarge Problems in Computational Mechanics
Solution of Superlarge Problems in Computational Mechanics

Author: James H. Kane

Publisher: Springer Science & Business Media

Published: 2012-12-06

Total Pages: 300

ISBN-13: 1461305357

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There is a need to solve problems in solid and fluid mechanics that currently exceed the resources of current and foreseeable supercomputers. The issue revolves around the number of degrees of freedom of simultaneous equations that one needs to accurately describe the problem, and the computer storage and speed limitations which prohibit such solutions. The goals of tHis symposium were to explore some of the latest work being done in both industry and academia to solve such extremely large problems, and to provide a forum for the discussion and prognostication of necessary future direc tions of both man and machine. As evidenced in this proceedings we believe these goals were met. Contained in this volume are discussions of: iterative solvers, and their application to a variety of problems, e.g. structures, fluid dynamics, and structural acoustics; iterative dynamic substructuring and its use in structural acoustics; the use of the boundary element method both alone and in conjunction with the finite element method; the application of finite difference methods to problems of incompressible, turbulent flow; and algorithms amenable to concurrent computations and their applications. Furthermore, discussions of existing computational shortcomings from the big picture point of view are presented that include recommendations for future work.

Electromagnetic Analysis and Design in Magnetic Resonance Imaging
Electromagnetic Analysis and Design in Magnetic Resonance Imaging

Author: Jianming Jin

Publisher: Routledge

Published: 2018-02-06

Total Pages: 304

ISBN-13: 1351453408

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This book presents a comprehensive treatment of electromagnetic analysis and design of three critical devices for an MRI system - the magnet, gradient coils, and radiofrequency (RF) coils. Electromagnetic Analysis and Design in Magnetic Resonance Imaging is unique in its detailed examination of the analysis and design of the hardware for an MRI system. It takes an engineering perspective to serve the many scientists and engineers in this rapidly expanding field. Chapters present: an introduction to MRI basic concepts of electromagnetics, including Helmholtz and Maxwell coils, inductance calculation, and magnetic fields produced by special cylindrical and spherical surface currents principles for the analysis and design of gradient coils, including discrete wires and the target field method analysis of RF coils based on the equivalent lumped-circuit model as well as an analysis based on the integral equation formulation survey of special purpose RF coils analytical and numerical methods for the analysis of electromagnetic fields in biological objects With the continued, active development of MRI instrumentation, Electromagnetic Analysis and Design in Magnetic Resonance Imaging presents an excellent, logically organized text - an indispensable resource for engineers, physicists, and graduate students working in the field of MRI.

Multiscale Modeling and Simulation in Science
Multiscale Modeling and Simulation in Science

Author: Björn Engquist

Publisher: Springer Science & Business Media

Published: 2009-02-11

Total Pages: 332

ISBN-13: 3540888578

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Most problems in science involve many scales in time and space. An example is turbulent ?ow where the important large scale quantities of lift and drag of a wing depend on the behavior of the small vortices in the boundarylayer. Another example is chemical reactions with concentrations of the species varying over seconds and hours while the time scale of the oscillations of the chemical bonds is of the order of femtoseconds. A third example from structural mechanics is the stress and strain in a solid beam which is well described by macroscopic equations but at the tip of a crack modeling details on a microscale are needed. A common dif?culty with the simulation of these problems and many others in physics, chemistry and biology is that an attempt to represent all scales will lead to an enormous computational problem with unacceptably long computation times and large memory requirements. On the other hand, if the discretization at a coarse level ignoresthe?nescale informationthenthesolutionwillnotbephysicallymeaningful. The in?uence of the ?ne scales must be incorporated into the model. This volume is the result of a Summer School on Multiscale Modeling and S- ulation in Science held at Boso ¤n, Lidingo ¤ outside Stockholm, Sweden, in June 2007. Sixty PhD students from applied mathematics, the sciences and engineering parti- pated in the summer school.