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Electric Field Distributions in Laser Drilled Voids of Polymeric Test Samples

IEEE ACCESS 2024年 12卷 64351-64359页

作者： Xu, Yue Davey, Kent Zhao, Wenping Hebner, Robert E. Yazdani, Miad Univ Texas Austin Ctr Electromech Austin TX 78758 USA Raytheon Technol Res Ctr East Hartford CT 06108 USA

Future electric transportation systems are expected to employ electrical power trains with higher operating voltage and power density. Therefore, compact and reliable insulation systems are important, since they influence the system integration, thermal resistance, and parasitic inductance. In this paper, experiments and analysis show behavior which are not observed with mechanically produced holes before. A boundary element analysis of the electric field distribution around the voids reveals why these new observations are identified in voids with relatively sharp corners. The electric field computation shows conditions under which there is electric field enhancement at the void periphery. This drives the partial discharge (PD) activity and the erosion growth away from the center of the voids.

关键词： Electric fields Permittivity Polymers Liquids Electrodes Transportation Testing boundary-element methods Insulation life Partial discharges Interferometry boundary element electric field analysis insulation aging and breakdown partial discharge tomography White light interferometry

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Fast Fictitious Surface Charge Method for Calculation of Torso Surface Potentials 24

Fast Fictitious Surface Charge Method for Calculation of Tor...

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24th International Conference on the Computation of Electromagnetic Fields (COMPUMAG)

作者： Petkovic, Bojana Ziolkowski, Marek Toepfer, Hannes Haueisen, Jens Tech Univ Ilmenau Adv Electromagnet Grp D-98693 Ilmenau Germany Tech Univ Ilmenau Inst Biomed Engn & Informat D-98693 Ilmenau Germany

ISBN: (纸本)9798350301052

Well-established forward modeling methods in electrocardiography (ECG) require fine meshes to calculate the electric scalar potential at the body surface with high accuracy. We introduce a fast fictitious surface charge method (FSCM) with local mesh refinement and smart calculations of elements interactions which improves the accuracy of the calculations and, at the same time, preserves the performance speed.

关键词： boundary-element methods electric fields eletrocardiography numerical analysis.

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Designing a High-Performance boundary element Library With OpenCL and Numba

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COMPUTING IN SCIENCE & ENGINEERING 2021年第4期23卷 18-28页

作者： Betcke, Timo Scroggs, Matthew W. UCL London WC1E 6BT England Univ Cambridge Cambridge CB2 1TN England

The Bempp boundary element library is a well-known library for the simulation of a range of electrostatic, acoustic, and electromagnetic problems in homogeneous bounded and unbounded domains. It originally started as a traditional C++ library with a Python interface. Over the last two years, we have completely redesigned Bempp as a native Python library, called Bempp-cl, that provides computational backends for OpenCL (using PyOpenCL) and Numba. The OpenCL backend implements kernels for GPUs and CPUs with SIMD optimization. In this article, we discuss the design of Bempp-cl, provide performance comparisons on different compute devices, and discuss the advantages and disadvantages of OpenCL as compared to Numba.

关键词： Libraries Kernel C plus plus languages Python Integral equations boundary-element methods Complexity theory

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Parameters Optimization of Oyster Wave Energy Converter Devices Using Artificial Neural Network Model

Parameters Optimization of Oyster Wave Energy Converter Devi...

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Power, Energy and Electrical Engineering (CPEEE), International Conference on

作者： Santanu Kumar Dash Santanu Koley Shrabani Mondal Department of Mathematics Birla Institute of Technology & Science-Pilani Hyderabad India Department of Chemistry Physical Chemistry Section Jadavpur University Kolkata India

ISBN: (数字)9798331520090

ISBN: (纸本)9798331520106

A supervised machine learning model based on artificial neural network (ANN) is used for the optimization of various parameters of an Oyster device. Oyster is a surface-piercing flap type device which works in nearshore environment and extracts energy by pitching about a horizontal axis parallel to the seabed. In this study, the shape parameters associated with the Oyster's flap and foundation will be taken as input parameters to the ANN model and the efficiency of the Oyster device will be considered as output parameter. Initially, the problem will be solved using 3D boundary element Method. For the training and testing database, Latin Hypercube Sampling technique will be used to obtain highly stratified input samples. The developed ANN model will be used to generate a large dataset consisting of combinations of various input parameters and associated output parameter. These large datasets will be used for the optimization purpose to achieve maximum efficiency from the Oyster device.

关键词： Training Damping Three-dimensional displays Shape Artificial neural networks Mathematical models boundary-element methods Wave energy conversion Optimization Testing

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Comparison of Rigid and Modular Oscillating Wave Surge Converters

Comparison of Rigid and Modular Oscillating Wave Surge Conve...

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Iranian Conference on Renewable Energy and Distributed Generation (ICREDG)

作者： Mohammad Erfan Khani Hassan Ghassemi Hamid Reza Ghafari Department of Maritime Engineering Amirkabir University of Technology Tehran Iran

ISBN: (数字)9798331525132

ISBN: (纸本)9798331525149

Climate change and the increasing demand for clean energy have led to a growing interest in marine renewable energy, particularly wave energy converters (WECs). This study compares two distinct geometrical designs of bottom-hinged, nearshore oscillating wave surge converters (OWSCs): Rigid and Modular. OWSCs are also known as Flap-type wave energy converters. An OWSC is usually installed perpendicular to the wavefront and converts the surge motion of the wave into rotational motion through a hinge and captures wave power. Simulations were carried out with the boundary element method using the three-dimensional radiation/diffraction theory, which is employed by the ANSYS-AQWA software. Regular Airy wave under different wave periods from 5 to 15 s and constant wave height (2 m) was considered as an environmental condition based on wave records of Chabahar port. At first, a validation procedure has been done. Then, the study determines the optimal damping coefficient for the power take-off (PTO) system in relation to the average absorbed power. Based on the results, at optimum condition, the Modular OWSC is 260 percent better than the Rigid type.

关键词： Damping Solid modeling Wave power Sea measurements Fasteners Software Shock absorbers boundary-element methods Surges Wave energy conversion

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HBEM and Conformal Mapping Application for Characteristic Parameters Calculation of Two-Wire Lines

HBEM and Conformal Mapping Application for Characteristic Pa...

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International Symposium on Electrical Apparatus and Technologies (SIELA)

作者： Isidora Jovanović Natalija Ivković Mirjana Perić Ana Vušković Nebojsa Raičević Dept. of Theoretical El. Eng. University of Niš Faculty of Electronic Engineering Niš Serbia

ISBN: (数字)9798350382365

ISBN: (纸本)9798350382372

The object of this paper is the comparison of values of the capacitance per unit length and characteristic impedance of two-wire transmission lines obtained through the application of the conformal mapping method known as the Joukowsky transform and the hybrid boundary element method (HBEM). The numerical results are presented in tabular and graphical form.

关键词： Power transmission lines Correlation Conformal mapping Transforms Capacitance Impedance boundary-element methods

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On a High-Frequency Analysis of Some Relevant Integral Equations in Electromagnetics

On a High-Frequency Analysis of Some Relevant Integral Equat...

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International Conference on Electromagnetics in Advanced Applications (ICEAA)

作者： Viviana Giunzioni Adrien Merlini Francesco P. Andriulli Department of Electronics and Telecommunications Politecnico di Torino Turin Italy Microwaves Department IMT Atlantique Brest France

ISBN: (数字)9798350360974

ISBN: (纸本)9798350360981

In this contribution we analyze the spectral properties of some commonly used boundary integral operators in computational electromagnetics and of their discrete counterparts, highlighting peculiar features of their spectra. In particular, a comparison with the eigenvalues of the continuous operators will be presented that highlights deviations in the high frequency regime and impacts, in a peculiar way, the accuracy of the numerical solutions of each formulation. A study and a proactive analysis of numerical results from standard boundary element solvers and the predictions from the theoretical analysis will corroborate the analytical framework employed and the validity of our observations.

关键词： Accuracy Integral equations Computational electromagnetics Eigenvalues and eigenfunctions High frequency boundary-element methods Electromagnetics Standards

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A Higher-order BEM Discretization Scheme for the EEG Forward Problem

A Higher-order BEM Discretization Scheme for the EEG Forward...

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Progress in Electromagnetic Research Symposium (PIERS)

作者： Rui Chen Mengmeng Li Dazhi Ding School of Microelectronics (School of Integrated Circuits) Nanjing University of Science and Technology Nanjing China

ISBN: (数字)9798350375909

ISBN: (纸本)9798350375916

The electroencephalographic (EEG) imaging requires the analysis of the EEG forward problem that can be achieved using the boundary element method (BEM). Among different BEM discretization approaches, higher-order schemes are preferred due to their better solution accuracy. Conventional higher-order discretization schemes use curved patches as the boundary elements and isoparametric methods for the electric potential interpolation. However, the order of the interpolation depends on that of the curved patches, i.e., one needs to regenerate the mesh of the boundaries to use higher-order interpolation functions, which is not convenient in practical. In this article, we propose a novel higher-order BEM discretization scheme for the EEG forward problem. The order of the interpolation of the proposed scheme is independent from that of the curved patches, which is more convenient than the conventional schemes. A numerical example is presented to verify the accuracy and flexibility of the proposed scheme.

关键词： Interpolation Electric potential Accuracy Imaging Electroencephalography boundary-element methods Electromagnetics

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Simulation of Echoes from Surface Ship Based on Highlight Model

Simulation of Echoes from Surface Ship Based on Highlight Mo...

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IEEE International Conference on Signal Processing, Communications and Computing (ICSPCC)

作者： Xin Fa Haiyan Wang Xiaohong Shen Feifei Pang School of Marine Science and Technology Northwestern Polytechnical University Xi'an China School of Electronics and Information Xi'an Polytechnic University Xi'an China

ISBN: (数字)9798350366556

ISBN: (纸本)9798350366563

The simulation of the amplitude factor of the echo for traditional highlight models varies inaccurately with azimuth angle, and the established echo highlight model only considers the scenario where the target and torpedo are at the same horizontal plane, without considering the situation where the torpedo is positioned below the target at a large elevation angle. In this paper, the boundary element method is adopted to calculate the azimuthal variation of the target strength for different elevation angles of the surface ship's overall underwater portion and three highlight parts (bow, hull, and stern). Based on this, the echo simulation of the surface ship at all azimuth angles is realized based on the highlight model, constructing a three-highlight surface ship echo model. Compared with the traditional highlight model, it establishes a highlight model of the surface ship echo at large elevation angles, which is closer to the actual scenario of torpedo attacking surface ships, and more accurately simulates the fluctuations of the amplitude factors of the target echo highlights. It better solves the problem of echo model's distortion caused by occlusion effects between highlights. From the simulation results, this model can more accurately simulate the basic characteristics of active sonar echoes, and has important theoretical significance and practical application value in the field of surface ship echo analysis.

关键词： Analytical models Fluctuations Azimuth Computational modeling Simulation Sonar applications Distortion boundary-element methods Marine vehicles Surface treatment

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On a Novel Calderón Preconditioning Strategy Based on High-Order Quasi-Helmholtz Projectors

On a Novel Calderón Preconditioning Strategy Based on High-...

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International Conference on Electromagnetics in Advanced Applications (ICEAA)

作者： Johann Bourhis Damiano Franzò Adrien Merlini Francesco P. Andriulli Politecnico di Torino Turin Italy IMT Atlantique Brest France

ISBN: (数字)9798350360974

ISBN: (纸本)9798350360981

The first of Calderón identities indicates that the operator of the electric field integral equation (EFIE) can potentially act as a preconditioner for itself. However, the discretization of this preconditioning operator via the boundary element method (BEM) requires constructing a dual space commonly defined on a barycentric refinement of the orginal mesh. This contribution introduces a novel Calderón strategy that leverages high-order quasi-Helmholtz projectors. Unlike the standard strategies, which are based on barycentric refinements, a dual space is obtained by combinating functions of higher order. This strategy allows the development of a discretization of the Calderón identity that is suitable for arbitrary order. The well-conditioning of the proposed formulation is investigated, and numerical results are presented to corroborate the theory.

关键词： Integral equations boundary-element methods Electric fields Electromagnetics Standards

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