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This paper presents a 3-D variable magnetization and Stoner--Wohlfarth (VMSW) method developed by expanding the conventional 2D-VMSW model. The 3-D VMSW method enables us to estimate distributions of remnant magnetization in magnetized permanent magnets in three dimensions. Index Terms--Anisotropic permanent magnet, finite-element method (FEM), magnetization process, remnant magnetization, variable magnetization and Stoner--Wohlfarth (VMSW) method.

This paper presents results obtained in the designing of a heating device, which utilized eddy current induced by rotating permanent magnets. The finite-element method, by using overlap grid coordinate system, is used for the eddy-current analyses. In order to solve eddy-current problems that consist of several conductive objects, which are moving in magnetic field, we have to remesh the region under consideration according to those positions, in the step-by-step computation. To reduce the computation time, a composite mesh scheme is introduced into such eddy-current problems. The heat conduction analysis is also carried out after calculating the eddy-current distributions. The results show that the device is very useful to dry powders and grains. Index Terms--Eddy current, finite-element method, heating device, induction heating, overlap grid coordinate system, permanent magnet.

This paper presents the two-dimensional vector magnetic property of the grain-oriented electrical steel sheet. The local magnetic characteristics are varied with the interaction of domain structure in the crystal grains, because the grain-oriented electrical steel sheets are composed of many crystal grains. Therefore, it is necessary to evaluate the local magnetic characteristic of electrical steel sheet to improve the magnetic properties. However, the local magnetic characteristic, including hysteresis, was difficult to express numerically with the conventional constitutive relation. In this paper, the influence of the specific magnetic permeability of the grain boundary on the magnetic power loss properties has been investigated numerically. In the numerical simulation, the finite-element method with the E&SS modeling is used to consider the grain structure and its orientation. Index Terms--Crystal grain, E&SS modeling, finite-element method (FEM), grain-oriented electrical steel sheet, magnetic power loss, two-dimensional (2-D) vector magnetic property.

This paper presents a magnetic field analysis of a moving magnetic field type sensor with shading coils developed for eddy current testing. The cracks and defects that are very difficult to detect with the conventional method, can be detected by using this sensor. In this paper, we have carried out the magnetic field analysis with the 2-D and 3-D finite element methods to show the effectiveness of this sensor. Index terms - Moving magnetic field, shading coil, eddy current testing, finite element method.

This paper presents results obtained in numerical simulations of a high-frequency induction heating problem. The coupled thermal and magnetic field problem taking account of nonlinear material characteristics on temperature is analyzed by axisymmetric finite element method. Besides, an inhomogeneous flow of the current in the high-frequency induction coil is considered in this formulation. Index Terms - High-frequency induction heating, finite element method, nonlinear material characteristics, coupled thermal and magnetic field problem.

This paper presents a new formulation of axisymmetric upwind finite element method and a composite mesh scheme with a new sliding element. The advantage of this method is that the computing time can be considerably reduced in comparison with that of the conventional composite mesh schemes. Furthermore we achieve simplicity of the upwinding formulation and accurate calculation of the motional term in the eddy current problems. Index terms - Composite mesh scheme, sliding element, upwind interpolation function, eddy current, finite element method.

This paper presents an optimal design method of high-frequency quenching coil. We have previously reported some optimal design methods of plural permanent magnets with the two- and three-dimensional boundary elements. In this paper, to obtain an optimum coil shape for the purpose of uniform heating, the size modification element is expanded to axisymmetric eddy current problem. The technique is based on the specific element and the least square method, and the coil shape is modified iteratively. In an example for verification of the convergence, it is shown that our method is useful for the optimization of the high-frequency induction coils.

This paper presents a three-dimensional simulation of movement of metal in a levitation-melting apparatus. Since the metal is levitated in air and melted by induction heating, the levitating metal not only moves complexly in the vertical and horizontal direction, but also rotates round a horizontal axis. To improve the apparatus from a point of view of uniform heating and stability levitation, we have carried out the metal's moving simulation by combining the boundary element analysis and its motion equation.

This paper describes the three-dimensional (3-D) modeling of an induction heating system. To realize the suitable construction of a high-frequency induction heating coil, numerical computations of eddy currents and heat conduction have been carried out by using the finite-element method (FEM) and also taking into account the dependence of material properties on temperature. For a high-frequency induction heating coil, which is normally applicable for heat treatment, the tubular solenoid design is the most appropriate due to its high coil efficiency. Coil efficiency is that part of energy delivered to the coil, which is transferred to the workpiece. Besides coil efficiency, the heating pattern and the production rate are also important. As the heating pattern reflects the coil geometry, optimal coil design is a prerequisite to attain the desired heating. Several modifications, such as spacing in between coil turns, the motion of the workpiece relative to the coil, and dimensional parameters, were carried out until optimal design was achieved. Index Terms--Finite-element method (FEM), high-frequency, induction heating, optimized coil.