电磁分析与应用期刊(英文)最新文献_第5页

An Empirical Relation for Vegetation Fuel Flames Breakdown Electric Field Strength 植被燃料火焰击穿电场强度的经验关系

电磁分析与应用期刊(英文) Pub Date : 2019-11-11 DOI: 10.4236/jemaa.2019.1111013

K. Maabong, Kgakgamatso Marvel Mphale, Douglas Letsholathebe, S. Chimidza, Phenyo Thebenyane

{"title":"An Empirical Relation for Vegetation Fuel Flames Breakdown Electric Field Strength","authors":"K. Maabong, Kgakgamatso Marvel Mphale, Douglas Letsholathebe, S. Chimidza, Phenyo Thebenyane","doi":"10.4236/jemaa.2019.1111013","DOIUrl":"https://doi.org/10.4236/jemaa.2019.1111013","url":null,"abstract":"The compulsion to provide reliable electric power for sustenance of socio-economic development is vital for most of southern Africa states. The demand for the resource in the region is anticipated to escalate in the next couple of decades. However, there is a deleterious effect of fire-induced power disruption which is observed in many countries. The mechanism through which the disruption occurs is currently a subject of current research in electric power distribution. It has been observed that streamer initiated conduction channel provides a means of high voltage electric power flashover. The main purpose of this study is to determine the empirical expression for breakdown electric field strength of vegetation fires. The breakdown field was measured from vegetation fuel (Peltophorum africanum) flames at different combustion temperatures. The data is essential for validation of simulation schemes which are necessary for evaluation of power grid systems reliability under extreme wildfire weather conditions. In this study, Peltophorum africanum fuels were ignited in a cylindrically shaped steel burner which was fitted with a Type-K thermocouple to measure flame temperature. The fuels consisted of dried fine twig (≤0.8 mm O) and limb wood (≥10 mm O) litter. Two copper pinned-electrodes supported by retort stands were mounted to the burner and energized to a high voltage. This generated a strong electric field sufficient to initiate dielectric breakdown in the flames. The measured electric field strength was plotted against flame temperatures and fit with a non-linear relation to give the empirical relation.","PeriodicalId":58231,"journal":{"name":"电磁分析与应用期刊(英文)","volume":" ","pages":""},"PeriodicalIF":0.0,"publicationDate":"2019-11-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"47754254","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Base Thickness Optimization of a (n+-p-p+) Silicon Solar Cell in Static Mode under Irradiation of Charged Particles 带电粒子辐照下静态模式下（n+-p-p+）硅太阳能电池基极厚度的优化

电磁分析与应用期刊(英文) Pub Date : 2019-10-11 DOI: 10.4236/jemaa.2019.1110012

Mamadou Lamine Ba, N. Thiam, M. Thiame, Youssou Traoré, Masse Samba Diop, M. Ba, Cheikh Sarr, M. Wade, G. Sissoko

引用次数: 15

Reduced Vector Helmholtz Wave Equation Analysis on the Wave-Number Side 波数侧的简化矢量亥姆霍兹波动方程分析

电磁分析与应用期刊(英文) Pub Date : 2019-09-29 DOI: 10.4236/jemaa.2019.119011

R. Ott

引用次数: 0

Dual Band BPF Based on Parallel Coupled Lines Loaded by Open Stubs for Ku-Band Satellite Applications ku波段卫星应用中基于开路存根负载并行耦合线的双频BPF

电磁分析与应用期刊(英文) Pub Date : 2019-09-17 DOI: 10.4236/jemaa.2019.119010

Ahmed S. I. Amar, O. Dardeer, Abdelhaleem A. Zekry

引用次数: 0

Combination of Metal Shielding and Distance Estimation for Electromagnetic Compatibility Guarantee 金属屏蔽与距离估计相结合的电磁兼容性保证

电磁分析与应用期刊(英文) Pub Date : 2019-09-17 DOI: 10.4236/jemaa.2019.119009

Nguyen Duc Truong, Tran Van Nghia, Bui Duc Chinh, Ho Quang Quy

{"title":"Combination of Metal Shielding and Distance Estimation for Electromagnetic Compatibility Guarantee","authors":"Nguyen Duc Truong, Tran Van Nghia, Bui Duc Chinh, Ho Quang Quy","doi":"10.4236/jemaa.2019.119009","DOIUrl":"https://doi.org/10.4236/jemaa.2019.119009","url":null,"abstract":"In this paper, a solution for electromagnetic compatibility guarantee based on the combination of metal shielding and circuit components distance estimation methods is presented. The electromagnetic noises generated from a working radio-electronic unit can expand into the space and act on other around radio-electronic units. An EMC guaranteed radio-electronic unit by the suitable technique method will not cause the electromagnetic noise to others. In opposition, it will not be under electromagnetic action from another one. Due to the power of electromagnetic noise, the metal shielding, distance estimation or other technique methods should be used to guarantee EMC. Every method has own advantage as so as weakness for detail radio-electronic unit, so it is necessary to choose a suitable method to guarantee EMC for them, the combination of metal shielding and distance estimation is a choice, for example. The proposed solution has been evaluated by using CST (Computer Simulation Technology) software and EMxpertEHX analyzer in oscillator circuit context. The simulated results on CST show that the proposed solution decreases the electromagnetic radiation about of 39.1 dB at frequency 500 MHz in comparison to results when nothing electromagnetic compatibility methods are not used. The experimental results on the oscillator circuit are presented. The electromagnetic radiation reduction of the oscillator circuit is about of (25 - 30) dB. In comparison to individual metal shielding and distance estimation methods, the effectiveness of the proposed solution for electromagnetic compatibility guarantee is significantly increased.","PeriodicalId":58231,"journal":{"name":"电磁分析与应用期刊(英文)","volume":" ","pages":""},"PeriodicalIF":0.0,"publicationDate":"2019-09-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"42226366","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Regularities of Nanofocusing of the Electromagnetic Field of a Fractal Rough Surface 分形粗糙表面电磁场的纳米聚焦规律

电磁分析与应用期刊(英文) Pub Date : 2019-08-29 DOI: 10.4236/jemaa.2019.118008

N. N. Grinchik, G. Zayats, O. Boiprav, K. V. Dobrego, Volha A. Prykhodzka

引用次数: 0

Effect of Exponentially Temperature-Dependent Viscosity on the Onset of Penetrative Ferro-Thermal-Convection in a Saturated Porous Layer via Internal Heating 指数温度依赖粘度对饱和多孔层内加热渗透铁热对流开始的影响

电磁分析与应用期刊(英文) Pub Date : 2019-07-31 DOI: 10.4236/JEMAA.2019.117007

R. Nataraj, S. Bhavya

{"title":"Effect of Exponentially Temperature-Dependent Viscosity on the Onset of Penetrative Ferro-Thermal-Convection in a Saturated Porous Layer via Internal Heating","authors":"R. Nataraj, S. Bhavya","doi":"10.4236/JEMAA.2019.117007","DOIUrl":"https://doi.org/10.4236/JEMAA.2019.117007","url":null,"abstract":"The effect of viscosity depending exponentially on temperature on the onset of penetrative ferro-thermal-convection (FTC) in a saturated horizontal porous layer in the presence of vertical magnetic field is investigated. The bounding surface of the ferrofluid layer is considered to be rigid-rigid and insulated to temperature perturbations. The resulting eigenvalue problem is solved numerically using the Galerkin technique and also analytically by a regular perturbation technique with wave number as a perturbation parameter. The analytical and numerical results are found to be concurrence. The characteristics of stability of the system are strongly dependent on the viscosity parameter B. The effect of B on the onset of ferroconvection in a porous layer is dual in nature depending on the choices of physical parameters and a sublayer starts to form at higher values of B. Whereas, increase in magnetic number M1 and the Darcy number Da is to advance the onset of ferroconvection in a porous layer. The nonlinearity of fluid magnetization M3 is found to have no influence on the onset of ferroconvection.","PeriodicalId":58231,"journal":{"name":"电磁分析与应用期刊(英文)","volume":"1 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2019-07-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"70292660","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 2

Simulated Experiments for Teaching CAD Techniques Using Analytic and Finite Element Solutions of Electromagnetic Two-Dimensional Problems with Longitudinal Symmetry 利用纵向对称电磁二维问题的解析解和有限元解进行CAD技术教学的模拟实验

电磁分析与应用期刊(英文) Pub Date : 2019-06-30 DOI: 10.4236/JEMAA.2019.116006

Antônio Flavio Licarião Nogueira, R. Weinert, Leonardo José Amador Salas Maldonado

{"title":"Simulated Experiments for Teaching CAD Techniques Using Analytic and Finite Element Solutions of Electromagnetic Two-Dimensional Problems with Longitudinal Symmetry","authors":"Antônio Flavio Licarião Nogueira, R. Weinert, Leonardo José Amador Salas Maldonado","doi":"10.4236/JEMAA.2019.116006","DOIUrl":"https://doi.org/10.4236/JEMAA.2019.116006","url":null,"abstract":"The paper describes an approach to teaching low-frequency electromagnetic CAD techniques to undergraduate students pursuing a degree course in electrical engineering. The simulated experiments make use of a two-dimensional open-access software based on the finite-element method. At the laboratory meetings, the problems are initially solved analytically. Upon this, students learn how to create the numeric model and how to define the sequence of field problems that lead to the required solution. Simulation tasks based on a force-producing electromagnet are used to introduce numeric techniques to determine magnetic field distribution, evaluation of energy storage and generation of magnetic forces. The nature of the magnetic force generated in the air gaps of the C-core electromagnet is explained in detail. Magnetic forces are calculated by the classical and weighted versions of the method of Maxwell stress tensor. The paper provides all the basic elements required for further exploration of devices with longitudinal symmetry.","PeriodicalId":58231,"journal":{"name":"电磁分析与应用期刊(英文)","volume":" ","pages":""},"PeriodicalIF":0.0,"publicationDate":"2019-06-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"45153627","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Multiphysics Analysis for Thermal Management of a 3 MeV, 325 MHz Radio Frequency Quadrupole Accelerator for Indian Spallation Neutron Source 印度散裂中子源3mev, 325mhz射频四极加速器热管理的多物理场分析

电磁分析与应用期刊(英文) Pub Date : 2019-05-31 DOI: 10.4236/JEMAA.2019.115005

N. Sharma, C. Paul, S. Joshi, G. Kane, A. Chaturvedi

{"title":"Multiphysics Analysis for Thermal Management of a 3 MeV, 325 MHz Radio Frequency Quadrupole Accelerator for Indian Spallation Neutron Source","authors":"N. Sharma, C. Paul, S. Joshi, G. Kane, A. Chaturvedi","doi":"10.4236/JEMAA.2019.115005","DOIUrl":"https://doi.org/10.4236/JEMAA.2019.115005","url":null,"abstract":"We present multiphysics design studies for thermal management of a 325 MHz 3 MeV Radio Frequency Quadrupole (RFQ) structure for the front end of 1 GeV proton linac for proposed Indian Spallation Neutron Source (ISNS). Physics design of RFQ for ISNS application has been carried out for 10% (maximum) duty factor. During high power operation of RFQ, RF-induced heating would result in temperature rise, thermal deformations and frequency shift of RFQ from designed values. Therefore thermal management is one of the important design considerations for RFQ development. During design studies, electromagnetic analysis of RFQ cavity is performed to compute RF induced heat fluxes on RFQ surfaces using SUPERFISH and ANSYS software. Simulated results for both codes were compared and found in well agreement. A water cooling scheme has been designed to absorb RF induced heat from RFQ structure. Cooling parameters are optimized by employing univariate search method optimization technique. An RF-Thermal-Structural-RF coupled multi-physics analysis methodology is developed to evaluate thermal induced frequency detuning of ISNS RFQ structure. Parametric studies are carried out to investigate the effect of cooling water temperatures on RFQ frequency. Based on analysis results, cooling water temperatures are varied to restore RFQ frequency to designed values. Thus, water cooling will not only remove heat from structure, but it will also be used for online control of resonating frequency during steady state operation of RFQ structure. Results of numerical studies carried out for thermal management of ISNS RFQ are presented in this paper.","PeriodicalId":58231,"journal":{"name":"电磁分析与应用期刊(英文)","volume":" ","pages":""},"PeriodicalIF":0.0,"publicationDate":"2019-05-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"48933432","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Electrostatic and Magnetostatic Forces That Arise from Electrostatic and Magnetostatic Pressures 由静电和静磁压力产生的静电力和静磁力

电磁分析与应用期刊(英文) Pub Date : 2019-03-29 DOI: 10.4236/JEMAA.2019.113003

José-Luis Jiménez-Ramírez, Ignacio Campos-Flores, J. Roa-Neri

引用次数: 0