简介:Theeffectofnanoparticleaggregationonthethermalconductivityofnanocompositesornanofluidsistypicallynonnegligible.Auniversalmodel(Maxwellmodel)includingnanoparticleaggregationismodifiedinordertopredictthethermalconductivityofnanocompositesmoreaccurately.Thepredictedthermalconductivitiesofsilicaandtitaniananoparticlepowdersarecomparedfirstwiththatmeasuredbyahot-wiremethodandthenwiththoseinpreviousexperimentalworks.Theresultsshowthatthereisgoodagreementbetweenourmodelandexperiments,andthatnanoparticleaggregationinananocompositeenhancesthethermalconductivitygreatlyandshouldnotbeignored.Becauseitconsiderstheeffectofaggregation,ourmodelisexpectedtoyieldprecisepredictionsofthethermalconductivityofcomposites.
简介:摘要:利用磁感应线圈可以间接测量轨道干扰电流的大小。本文在Maxwell平台对通电钢轨周围磁场进行了仿真,得到钢轨周边磁场强度分布,并由此研究设计磁感应线圈,以达到测量轨道干扰电流的目的。
简介:摘要:空载漏磁系数σ0是永磁电机计算和分析中一个重要参数。在工程实际中,空载漏磁系数一般根据永磁材料和磁极结构凭经验选取,给科研、工程人员分析计算永磁电机带来了一定误差。本文介绍一种利用Maxwell 2D来获得永磁电机空载漏磁系数的方法,并通过与试验值对比验证其准确性,最后对漏磁场进行分析,得出空载漏磁系数优化结论。
简介:介绍拟稳态Maxwell方程在电气工程领域的可计算建模及应用。对于含导电材料的电磁设备,拟稳态Maxwell方程是描述电流密度分布和欧姆损耗的常用模型,在电机、大型变压器等电气工程设备和集成电路等微电子技术领域有广泛应用。以国际计算电磁学会公布的TEAMWorkshopProblem7和21基准族问题为例,阐述拟稳态Maxwell方程的可计算建模和自适应有限元计算。
简介:Inthispaper,aunifiedmodelfortime-dependentMaxwellequationsindispersivemediaisconsidered.Thespace-timeDGmethoddevelopedin[29]isappliedtosolvetheunderlyingproblem.UnconditionalL2-stabilityanderrorestimateoforderOτr+1+hk+1/2areobtainedwhenpolynomialsofdegreeatmostrandkareusedforthetemporaldiscretizationandspatialdiscretizationrespectively.2-Dand3-Dnumericalexamplesaregiventovalidatethetheoreticalresults.Moreover,numericalresultsshowanultra-convergenceoforder2r+1intemporalvariablet.
简介:Westudythepartialregularityofweaksolutionstothe2-dimensionalLandauLifshitzequationscoupledwithtimedependentMaxwellequationsbyGinzburg-Landautypeapproximation.Outsideanenergyconcentrationsetoflocallyfinite2-dimensionalparabolicHausdorffmeasure,weprovetheuniformlocalC∞boundsfortheapproachingsolutionsandthenextractasubsequenceconvergingtoaglobalweaksolutionoftheLandau-Lifshitz-Maxwellequationswhicharesmoothawayfromfinitelymanypoints.
简介:在KaIuza-KIein理论中5维坐标变换的一个就用就是能导出一些对于4维Einstein-Maxwell方程和有关的标量方程的一些新解。利用这个方法,由Taub-NUT解我们生成了相应的解。
简介:Analternateyetgeneralformoftheclassicaleffectivethermalconductivitymodel(Maxwellmodel)fortwo-phaseporousmaterialsispresented,servinganexplicitthermo-physicalbasis.Itisdemonstratedthatthereducedeffectivethermalconductivityoftheporousmediaduetonon-conductingporeinclusionsiscausedbythemechanismofthermalstretching,whichisacombinationofreducedeffectiveheatflowareaandelongatedheattransferdistance(thermaltortuosity).