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This paper presents a numerical method to calculate shape of ferrofluid droplet that undergoes three effects: external magnetic field, gravitational force and surface tension. The shape is calculated using an equilibrium energy condition of the coupled system of electromagnetic field and gravitational field and surface tension. The shape of the ferrofluid is traced using level set method, where the...
Optimization metaheuristics, such as particle swarm optimization, ant colony and bacterial foraging strategies have become very popular for electromagnetic device design. The Artificial Bee Colony algorithm is another example of bio-inspired swarm intelligence approach which is competitive with other population-based algorithms and has the advantage of using fewer control parameters. In this work,...
In this paper the optimization of a transverse flux induction heating by means of a particle swarm optimizer is presented. The novelty of this work is represented by the fact that concentric multi-coil induction heaters have never been optimized before in their full three-dimensional complexity.
Two-port TEM cells with rectangular cross-section are commonly used to produce plane electromagnetic waves with high electric field. The non-uniformity of the system makes the use of numerical methods extremely useful in the design phase in order to achieve a very good behavior of the TEM cell over a wide frequency range of operation. In this paper an extended version of PEEC is used to study a real...
Electrical discharges; especially electrical discharges in air are still one of the most unexplored fields of the physics. Lately, there are numerical models of electrical discharges appearing, special group of which are simulations. It appeared that the finite element method (FEM) is not a good choice for simulations to base on. Instead of FEM charge simulation method (CSM) has been used in work...
Computation of electromagnetic fields in high resolution computational phantoms requires solving large linear systems. We present the application of Schwarz preconditioners with Krylov subspace methods for computing Extremely Low Frequency (ELF) induced fields in a phantom.
The deflation technique replaces small eigenvalues of a matrix with zeros to accelerate convergence of iterative linear solvers. In this paper, it is shown that the reason why recently proposed computational frameworks such as the explicit and implicit error corrections and singularity decomposition as well as the conventional AV method improve convergence in linear solvers is clarified from a view...
This paper presents a methodology and a tool for the coupled magnetic-structural with semi-analytical models. For this coupling, the magnetic model is available, we developed the structural-contact model for the cantilever beam and valid it by finite element simulation. This coupling is dedicated to the optimization process of MEMS/NEMS in general and to nano switch in particular.
Sizing by optimization usually implies a model definition able to link the desired objective and constrained functions with the design parameters. When gradient based optimization algorithms are used, highly accurate derivatives are required. Without special software solutions, this procedure easily becomes time-consuming or error-prone. In this paper, our goal is to first observe the modeling needs...
Automatic Differentiation (AD) is introduced as a powerful technique to compute derivatives of functions given in the form of computer programs in high level programming languages such FORTRAN, C or C++. The paper applies AD to compute error-free gradients of sizing models describing electromagnetic devices. Then, the obtained gradients are exploited by optimization algorithms. The goal is to find...
A vector optimizer, based on population based incremental learning (PBIL) method, is proposed and used to study a hard engineering inverse problem with good results.
This paper presents the study of a novel axial flux permanent magnet (AFPM) machine, which consist of the segmented stator and fractioned slot windings, with one rotor and double stator. In addition, the overhang effect of permanent magnet of the motor has been analyzed quantitatively. The overhang is used to enhance the force density in permanent magnet machine. According to the variation of overhang...
A stator turn fault in a symmetrical three-phase machine cause a large circulating current to flow and subsequently generated excessive heat in shorted turns, generate irregular control current of the three phase leads to demagnetization. In this paper, the effect of the circulating current in shorted turns on the demagnetization of PM and motor performance is analyzed by using FE analysis.
The permanent magnet synchronous machine with an external rotor is the most important device for high performance electrical drive systems in particular for hybrid electric vehicles. The paper presents finite element analyses of a such a machine in terms of a comparison of both Y- and Δ-connected stator windings. The influence on the most important design parameters such as electromagnetic torque...
This paper presents an investigation of the properties of square slot microstrip patch antennas. These antenna geometries are obtained by printing square slots in the conducting patches of rectangular microstrip antennas. Measured results of the return loss versus frequency are used in the ANN training. A particular set of measured results is used in the validation of the ANN. The effect of the feed...
An efficient mesh reconstruction method is proposed for remeshing the parameterized computation domain when using finite element method to optimize the shapes of electromagnetic devices. The proposed method has the merits of conserving the original structure of the mesh with minimal mesh deformation. The proposed method has been applied to TEAM workshop problem No. 25 and a permanent magnetic (PM)...
This paper presents a material modeling method of silicon steel sheet considering harmonic magnetic field in the model. A new experiment method that can provide magnetic property data of high-order harmonic magnetic field is introduced. A material modeling method associated with the measurement data is provided. A novel time periodic iterative method of finite element analysis (FEA) is proposed to...
The magnetic property of electrical steel sheet has an anisotropy even in the case of non-oriented material. In order to analyze the operating condition of a synchronous reluctance motor preciously, the magnetic field analysis considering the magnetic anisotropy of electrical steel sheet using the fixed-point method was carried out.
The multiconductor transmission line capacitance matrix for a densely-packed CNT bundle interconnect is computed by moment method solving the 2-D integral electrostatic problem in the transverse plane. The equivalent single conductor (ESC) capacitance is then evaluated self-consistently.
Mobile phones have become necessary communication devices in modern society. Linear vibrators excited with a vertical vibration at resonant frequency produce a silent, tactile signal and, compared with vibration motors, have excellent performance due to their simple structure. This paper introduces an optimal design methodology for linear vibrators through electromagnetic and mechanical coupling analysis...
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