Design Sensitivity Analysis And Optimization Of Electromagnetic Systems

This book presents a comprehensive introduction to design sensitivity analysis theory as applied to electromagnetic systems. It treats the subject in a unified manner, providing numerical methods and design examples. The specific focus is on continuum design sensitivity analysis, which offers significant advantages over discrete design sensitivity methods. Continuum design sensitivity formulas are derived from the material derivative in continuum mechanics and the variational form of the governing equation. Continuum sensitivity analysis is applied to Maxwell equations of electrostatic, magnetostatic and eddy-current systems, and then the sensitivity formulas for each system are derived in a closed form; an integration along the design interface. The book also introduces the recent breakthrough of the topology optimization method, which is accomplished by coupling the level set method and continuum design sensitivity. This topology optimization method enhances the possibility of the global minimum with minimised computational time, and in addition the evolving shapes during the iterative design process are easily captured in the level set equation. Moreover, since the optimization algorithm is transformed into a well-known transient analysis algorithm for differential equations, its numerical implementation becomes very simple and convenient. Despite the complex derivation processes and mathematical expressions, the obtained sensitivity formulas are very straightforward for numerical implementation. This book provides detailed explanation of the background theory and the derivation process, which will help readers understand the design method and will set the foundation for advanced research in the future.

This symposium was concerned with advanced computational and design techniques in applied electromagnetic systems including devices and materials. The scope of the proceedings cover a wide variety of topics in applied electromagnetic fields: optimal design techniques and applications, inverse problems, advanced numerical techniques, mechanism and dynamics of new actuators, physics and applications of magnetic levitation, electromagnetic propulsion and superconductivity, modeling and applications of magnetic fluid, plasma and arc discharge, high-frequency field computations, electronic device simulations and magnetic materials.

This publication covers topics in the area of applied electromagnetics and mechanics. Since starting in Japan in 1988, the ISEM has become a well-known international forum on applied electromagnetics.

This volume includes contributions on: field theory and advanced computational electromagnetics; electrical machines and transformers; optimization and interactive design; electromagnetics in materials; coupled field and electromagnetic components in mechatronics; induction heating systems; bioelectromagnetics; and electromagnetics in education.

The aim of this selection of papers is to bring together researchers working very deep in the basics of electromagnetic NDT on one hand and industrialist discussing their practical problems on the other hand. The papers cover topics as; Microwave applications and Material Characterization; General Eddy Current Inspection Tasks; Novel Techniques and Sensors; Magnetic Flux leakage Inspection; Steam Generator Eddy Current Inspection Tasks; and Material Characterization. Especially Novel Techniques and Sensors and Material Characterization are discussed on multiple papers. This publication gives a good overview of the many scientific problems in this area, but also explains the actual challenges for the scientific-technical community, like problems with in-line inspection of pipelines or the enhancing of the inspection performance in steam generator tubes inspection in the nuclear field. The material is important for scientists and engineers working in the field of electromagnetic non-destructive testing, in defect detection and sizing, as well as in material characterization.

This unique reference is the first to cover the theory of adjoint sensitivity analysis and explains how it can be applied to different types of electromagnetic structures. It is an invaluable book for anyone looking for an in-depth understanding of this useful theory for application in high-frequency electromagnetic problems. It uses the popular FDTD method to show how wideband sensitivities can be efficiently estimated for different types of materials and structures, and includes plenty of well-explained MATLAB(R) examples to help readers absorb the content more easily. Topics covered include a review of FDTD and an introduction to adjoint sensitivity analysis; sensitivity of the fields to changes in material parameters; sensitivity of S parameters; extension to dispersive material parameters, where the underlying FDTD algorithm must be modified; second-order sensitivity analysis; time-domain responses; and applications to nonlinear and anisotropic materials. This book will make the theory more understandable to the broadest possible audience. It will be useful for researchers and advanced students involved in computational techniques for electromagnetics, and other disciplines such as microwave, optics, acoustics, and semiconductor modelling.

Eddy current testing is a key technology among electromagnetic non-destructive testings at present and this situation was motivated by a stringent need to detect small cracks in tubing of a steam generator of nuclear power plants. In these five years the ECT technology has been enhanced very much, demonstrating that high performanced sensors for ECT are now ready to be applied to the annual inspection of steam generator tubing with use of arrayed micro sensors for ECT. In addition to the innovative technology, an inversion technique is being theoretically developed to make reconstruction of defects possible with use of data from the arrayed sensors. Rapid growth of interest in electromagnetic nondestructive evaluation have brought together experts from different parts of the world, as reflected in this work. The book is intended for engineers, researchers and practitioners working in the area of electromagnetism.

This book discusses response feature technology and its applications to modeling, optimization, and computer-aided design of high-frequency structures including antenna and microwave components. By exploring the specific structure of the system outputs, feature-based approaches facilitate simulation-driven design procedures, both in terms of improving their computational efficiency and reliability. These benefits are associated with the weakly nonlinear relationship between feature point coordinates and design variables, which—in the context of optimization—leads to inherent regularization of the objective functions. The book provides an overview of the subject, a definition and extraction of characteristic points, and feature-based design problem reformulation. It also outlines a number of numerical algorithms developed to handle local, global, and multi-criterial design, surrogate modeling, as well as uncertainty quantification. The discussed frameworks are extensively illustrated using examples of real microwave and antenna structures, along with numerous design cases. Introductory material on simulation-driven design, numerical optimization, as well as behavioral and physics-based surrogate modeling is also included. The book will be useful for readers working in the area of high-frequency electronics, including microwave engineering, antenna design, microwave photonics, magnetism and especially those who utilize electromagnetic (EM) simulation models in their daily routines.