Pub Date : 2019-11-11DOI: 10.4236/jemaa.2019.1111013
K. Maabong, Kgakgamatso Marvel Mphale, Douglas Letsholathebe, S. Chimidza, Phenyo Thebenyane
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.
为维持社会经济发展提供可靠电力的义务对大多数南部非洲国家至关重要。该地区对该资源的需求预计将在未来几十年内升级。然而，许多国家都观察到火灾造成的电力中断会产生有害影响。破坏发生的机制目前是配电领域的一个研究课题。已经观察到，流光引发的传导通道提供了一种高压电力闪络的手段。本研究的主要目的是确定植被火灾击穿电场强度的经验表达式。分解场是从不同燃烧温度下的植物燃料（Peltophorum africanum）火焰中测量的。这些数据对于验证模拟方案至关重要，而模拟方案对于评估极端野火天气条件下的电网系统可靠性是必要的。在这项研究中，非洲Peltophorum燃料在一个装有K型热电偶的圆柱形钢燃烧器中点燃，以测量火焰温度。燃料由干燥细树枝（≤0.8 mm O）和肢木（≥10 mm O）垃圾组成。由蒸馏器支架支撑的两个铜钉扎电极安装在燃烧器上，并通电至高电压。这产生了一个足以在火焰中引发介电击穿的强电场。测量的电场强度与火焰温度的关系被绘制出来，并与非线性关系拟合，得出经验关系。
{"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":null,"pages":null},"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}
Pub Date : 2019-10-11DOI: 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
In this work, we propose a method to determinate the optimum thickness of a monofacial silicon solar cell under irradiation. The expressions of back surface recombination velocity depending the damage coefficient (kl) and irradiation energy (op) are established. From their plots, base optimum thickness is deduced from the intercept points of the curves. The short-circuit currents Jsc0 and Jsc1 corresponding to the recombination velocity Sb0 and Sb1 are determinated and a correlation between the irradiation energy, the damage coefficient and optimum thickness of the base is established.
{"title":"Base Thickness Optimization of a (n+-p-p+) Silicon Solar Cell in Static Mode under Irradiation of Charged Particles","authors":"Mamadou Lamine Ba, N. Thiam, M. Thiame, Youssou Traoré, Masse Samba Diop, M. Ba, Cheikh Sarr, M. Wade, G. Sissoko","doi":"10.4236/jemaa.2019.1110012","DOIUrl":"https://doi.org/10.4236/jemaa.2019.1110012","url":null,"abstract":"In this work, we propose a method to determinate the optimum thickness of a monofacial silicon solar cell under irradiation. The expressions of back surface recombination velocity depending the damage coefficient (kl) and irradiation energy (op) are established. From their plots, base optimum thickness is deduced from the intercept points of the curves. The short-circuit currents Jsc0 and Jsc1 corresponding to the recombination velocity Sb0 and Sb1 are determinated and a correlation between the irradiation energy, the damage coefficient and optimum thickness of the base is established.","PeriodicalId":58231,"journal":{"name":"电磁分析与应用期刊(英文)","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2019-10-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"46361918","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}
Pub Date : 2019-09-29DOI: 10.4236/jemaa.2019.119011
R. Ott
The resolvent helps solve a PDE defined on all of wave-number space, . Almost all electromagnetic scattering problems have been solved on the spatial side and use the spatial Green’s function approach. This work is motivated by solving an EM problem on the Fourier side in order to relate the resolvent and the Green’s function. Methods used include Matrix Theory, Fourier Transforms, and Green’s function. A closed form of the resolvent is derived for the electromagnetic Helmholtz reduced vector wave equation, with Dirichlet boundary conditions. The resolvent is then used to derive expressions for the solution of the EM wave equation and provide Sobolev estimates for the solution.
{"title":"Reduced Vector Helmholtz Wave Equation Analysis on the Wave-Number Side","authors":"R. Ott","doi":"10.4236/jemaa.2019.119011","DOIUrl":"https://doi.org/10.4236/jemaa.2019.119011","url":null,"abstract":"The resolvent helps solve a PDE defined on all of wave-number space, . Almost all electromagnetic scattering problems have been solved on the spatial side and use the spatial Green’s function approach. This work is motivated by solving an EM problem on the Fourier side in order to relate the resolvent and the Green’s function. Methods used include Matrix Theory, Fourier Transforms, and Green’s function. A closed form of the resolvent is derived for the electromagnetic Helmholtz reduced vector wave equation, with Dirichlet boundary conditions. The resolvent is then used to derive expressions for the solution of the EM wave equation and provide Sobolev estimates for the solution.","PeriodicalId":58231,"journal":{"name":"电磁分析与应用期刊(英文)","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2019-09-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"41308110","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}
Pub Date : 2019-09-17DOI: 10.4236/jemaa.2019.119010
Ahmed S. I. Amar, O. Dardeer, Abdelhaleem A. Zekry
This paper presents a dual band Band Pass Filter (BPF) operating at both the downlink and uplink frequency bands for Ku-band satellite applications. The commonly used frequency band in mobile communications satellites is the Ku-band. These mobile satellite systems help connect remote regions, vehicles, ships, people and aircraft to other parts of the world and/or other mobile or stationary communications units, in addition to serving as navigation systems. The structure of the proposed filter is based on parallel coupled microstrip lines and four sections are used. Tuning the two operational bands can be achieved using two open-circuited stubs at the first and last sections of the parallel coupled microstrip lines. The proposed filter is adjusted to operate at 12.54 GHz and 14.14 GHz for downlink and uplink bands, respectively. The proposed dual band BPF is fabricated, measured, and good agreement is obtained between simulated and measured results.
{"title":"Dual Band BPF Based on Parallel Coupled Lines Loaded by Open Stubs for Ku-Band Satellite Applications","authors":"Ahmed S. I. Amar, O. Dardeer, Abdelhaleem A. Zekry","doi":"10.4236/jemaa.2019.119010","DOIUrl":"https://doi.org/10.4236/jemaa.2019.119010","url":null,"abstract":"This paper presents a dual band Band Pass Filter (BPF) operating at both the downlink and uplink frequency bands for Ku-band satellite applications. The commonly used frequency band in mobile communications satellites is the Ku-band. These mobile satellite systems help connect remote regions, vehicles, ships, people and aircraft to other parts of the world and/or other mobile or stationary communications units, in addition to serving as navigation systems. The structure of the proposed filter is based on parallel coupled microstrip lines and four sections are used. Tuning the two operational bands can be achieved using two open-circuited stubs at the first and last sections of the parallel coupled microstrip lines. The proposed filter is adjusted to operate at 12.54 GHz and 14.14 GHz for downlink and uplink bands, respectively. The proposed dual band BPF is fabricated, measured, and good agreement is obtained between simulated and measured results.","PeriodicalId":58231,"journal":{"name":"电磁分析与应用期刊(英文)","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2019-09-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"43245043","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}
Pub Date : 2019-09-17DOI: 10.4236/jemaa.2019.119009
Nguyen Duc Truong, Tran Van Nghia, Bui Duc Chinh, Ho Quang Quy
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.
{"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":null,"pages":null},"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}
Pub Date : 2019-08-29DOI: 10.4236/jemaa.2019.118008
N. N. Grinchik, G. Zayats, O. Boiprav, K. V. Dobrego, Volha A. Prykhodzka
A consistent physical and mathematical model of the propagation of electromagnetic waves in an inhomogeneous medium with strong discontinuities of the electromagnetic field at the interface of two media, which is a rough surface, was developed. Mathematical modeling of rough surfaces and their profiles was carried out using fractal geometry, which allows us to display the topology of the object as close as possible to reality. For real heterogeneous rough structures, we have developed a through-counting method that takes into account the continuity of the total current at the interfaces of adjacent media, the effect of induced surface charge and surface current. This approach lets one avoid the necessity to set surface impedances depending on the structure of the field being determined and on the material properties.
{"title":"Regularities of Nanofocusing of the Electromagnetic Field of a Fractal Rough Surface","authors":"N. N. Grinchik, G. Zayats, O. Boiprav, K. V. Dobrego, Volha A. Prykhodzka","doi":"10.4236/jemaa.2019.118008","DOIUrl":"https://doi.org/10.4236/jemaa.2019.118008","url":null,"abstract":"A consistent physical and mathematical model of the propagation of electromagnetic waves in an inhomogeneous medium with strong discontinuities of the electromagnetic field at the interface of two media, which is a rough surface, was developed. Mathematical modeling of rough surfaces and their profiles was carried out using fractal geometry, which allows us to display the topology of the object as close as possible to reality. For real heterogeneous rough structures, we have developed a through-counting method that takes into account the continuity of the total current at the interfaces of adjacent media, the effect of induced surface charge and surface current. This approach lets one avoid the necessity to set surface impedances depending on the structure of the field being determined and on the material properties.","PeriodicalId":58231,"journal":{"name":"电磁分析与应用期刊(英文)","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2019-08-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"42530048","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}
Pub Date : 2019-07-31DOI: 10.4236/JEMAA.2019.117007
R. Nataraj, S. Bhavya
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.
{"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":null,"pages":null},"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}
Pub Date : 2019-06-30DOI: 10.4236/JEMAA.2019.116006
Antônio Flavio Licarião Nogueira, R. Weinert, Leonardo José Amador Salas Maldonado
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.
{"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":null,"pages":null},"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}
Pub Date : 2019-05-31DOI: 10.4236/JEMAA.2019.115005
N. Sharma, C. Paul, S. Joshi, G. Kane, A. Chaturvedi
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.
{"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":null,"pages":null},"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}
Pub Date : 2019-03-29DOI: 10.4236/JEMAA.2019.113003
José-Luis Jiménez-Ramírez, Ignacio Campos-Flores, J. Roa-Neri
With the insight provided by a balance equation of electromagnetic momentum, we compare the force on a dielectric slab inside a capacitor with the force on a magnetizable rod inside a solenoid. We conclude that these forces are not exactly analogous, as usually thought. We present a device that is a proper analogy of the case of a dielectric slab inside a capacitor. Our analysis shows the significance of the electrostatic and magnetostatic pressures to the understanding of these effects and shows the conceptual differences between both cases.
{"title":"Electrostatic and Magnetostatic Forces That Arise from Electrostatic and Magnetostatic Pressures","authors":"José-Luis Jiménez-Ramírez, Ignacio Campos-Flores, J. Roa-Neri","doi":"10.4236/JEMAA.2019.113003","DOIUrl":"https://doi.org/10.4236/JEMAA.2019.113003","url":null,"abstract":"With the insight provided by a balance equation of electromagnetic momentum, we compare the force on a dielectric slab inside a capacitor with the force on a magnetizable rod inside a solenoid. We conclude that these forces are not exactly analogous, as usually thought. We present a device that is a proper analogy of the case of a dielectric slab inside a capacitor. Our analysis shows the significance of the electrostatic and magnetostatic pressures to the understanding of these effects and shows the conceptual differences between both cases.","PeriodicalId":58231,"journal":{"name":"电磁分析与应用期刊(英文)","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2019-03-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"47514473","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}
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