简介：Thenatureofthethree-dimensionaltransitionarisingintheflowpastacylinderisinvestigatedbyapplyingtheLifschitz-HameiritheoryalongspecialLagrangiantrajectoriesexistinginitswake.ResultsshowthatthevonKarmanstreetisunstablewithregardtoshort-wavelengthperturbations.Theasymptoticanalysispredictsthepossibleexistenceofbothsynchronous(asmodesAandB)andasynchronous(asmodeC)instabilities,eachassociatedtospecificLagrangianorbits.Theproposedstudyprovidesusefulqualitativeinformationontheoriginofthedifferentmodesbutnoquantitativeagreementbetweenthegrowthratespredictedbytheasymptoticanalysisandbyaglobalstabilityanalysisisobserved.Thereasonsforsuchmismatcharebrieflydiscussedandpossibleimprovementstothepresentanalysisaresuggested.

简介：柱体hydrogel在几何学简单并且容易综合，广泛地因此被用来调查hydrogel的胀大/缩小的不稳定性，许多不稳定性模式在文学被积累。不过，这种唯一的配置的不稳定性模式形成的机制充分远离是被理解。我们使用了并且延长，并且执行了抑制柱体hydrogel的胀大导致稳定性的线性不安分析聚合物胶化的最近发达的非线性的理论进圆柱的坐标。我们导出压力和联系平衡方程的增长明确的表达。我们为不稳定性的发作获得了批评条件并且在hydrogel的稳定性图上在细节探查了各种各样的参数的效果。稳定性图的变化的物理意思也被解释。

简介：Thephysicalmechanismforgenerationofstreamwisevortices(orribvortices)inthecylinderwakeisnumericallyinvestigatedwithafinite-differencescheme.Rayleigh’stheoryofcentrifugalinstabilityforinviscidaxisymmetricflowisextendedtoanalyzethe2-Dprimaryflows.Accordingly,ananalyticaldimensionlessgroupRay=-(r/vθ)■vθ/■r-1isderived,wherevθrepresentsthevelocityofafluidelementrelativetotheoncomingflow,risthelocalcurvatureradiusoftheelementpathline.CentrifugalinstabilityoccurswhenRay>0.StabilityanalysesarecarriedoutwiththisdiscriminantforprimaryflowsatdifferenttimelevelsinahalfsheddingperiodofthevonKarman(orvK)vortices.UnstableareasareidentifiedandthelocationsofribvorticesarecoincidentwellwiththeunstableareaswithinthefirstwavelengthofvKvorticesbehindthecylinder.Thenumericalresultsalsoshowthatribvorticesexperienceamplificationinthisregion.Itisapparentthatcentrifugalinstabilityplaysanimportantroleinthegenerationofribvorticesinthecylinderwake.

简介：Wepresentthesimulationofthedynamicsoffluid-cylinderinteractionsinanarrowthree-dimensionalchannelfilledwithaNewtonianfluid,usingaLagrangemultiplierbasedfictitiousdomainmethodologycombinedwithafiniteelementmethodandanoperatorsplittingtechnique.Asexpected,asettlingtruncatedcylinderturnsitsbroadsideperpendiculartothemainstreamdirectionandthecenterofmassmovestothecentralaxisofthechannel.Inthecaseoftwotruncatedcylinders,theyfirstmovearoundeachotherforawhileandthenstaytogetherina"T"shape.Afterthe"T"shapehasbeenformedforalongenoughtime,wefoundnovortexsheddingbehindthecylinders.Whensimulatingthefluidizationof60truncatedcylinders,wecapturedthefeaturesofinteractionsamongfluidizedcylindersasobservedinexperiments.

简介：FlowfieldsaroundarotatingcircularcylinderinauniformstreamarecomputedusingalowdimensionalGalerkinmethod.ResultsshowthattheformationofaFopplevortexpairbehindastationarycircularcylinderiscausedbythestructuralinstabilityinthevicinityofthesaddlelocatedattherearofthecylinder.Forrotatingcylinderabifurcationdiagramwiththeconsiderationoftwoparameters,ReynoldsnumberReandrotationparameterα,isbuiltbyakinematicanalysisofthesteadyflowfields.

简介：Theinertiasofthefluidandtheinnercylinderincoaxialcylinderrheometer(CACR)havegreatinfluenceontheunsteadyflowofnon-Newtonianfluid.EvenfortheNewtonianfluidthereexistthesocalled'stressovershoot'phenomenon.Inthepresentarticlethisphenomenonwasstudiedindetailandamethodcorrectingthemeasuredresultsforanunsteadyflowintherheometerwasproposed.Itisfoundthattheinertiaeffectofthefluidcanbeignoredwhenthegapbetweencylindersissmall.

简介：Corioliseffectisconsideredintheanalysisofarotatingpiezoelectrichollowcylinder.AninhomogeneousBesselequationgoverningtheradialmechanicaldisplacementisderived,whichcanbeapproximatedasanEulertypedifferentialequationwhenthecylinderisverythin.NumericalexamplesshowthattheCorioliseffectcanbesignificantundercertainconditions.

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简介：在动人的水平圆柱的热来源附近阶段变化材料融化的接触，在它的自己的重量下面下降了，在这篇文章被调查。在经常的表面热流动下面的一个融化的模型被建立。厚度和压力分布里面的分析结果融化层，稳定的融化速度被使用融化理论的接触获得。融化的法律被讨论，并且由温度差别与接触融化的相比开车。伪稳定的融化速度被热来源密度的热来源，和变化的热流动决定，这被发现在融化上有更少的效果速度。

简介：Inordertoinvestigatethescaleefectofturbulentflowaroundacircularcylinder,twosimilaritynumbers(criteria)basedonturbulentkineticanddissipationratesassociatedwiththefluctuationcharacteristicsofturbulencewakearededucedbyanalyzingtheReynoldsaveragedNavier–Stokesequations(RANS).TheRNGk–εmodelsandfinitevolumemethodareusedtosolvethegoverningequationsandthesecond-orderimplicittimeandupwindspacediscretizationalgorithmsareusedtodiscretethegoverningequations.Anumericalcomputationofflowparametersaroundatwo-dimensionalcircularcylinderwithReynoldsnumbersrangingfrom102to107isaccomplishedandtheresultindicatesthatthefluctuationofturbulenceflowalongthecenterlineinthewakeofcircularcylindercanneverbechangedwithincreasingReynoldsnumberswhenRe3×106.Thisconclusionisusefulforcontrollingthescaleofnumericalcalculationsandforapplyingmodeltestdatatoengineeringpractice.

简介：Theequationofstressintensityfactors(SIF)ofinternallypressurizedthick-walledcylinderwasusedasthereferencecase.SIFequationofrotatingthick-walledcylindercontainingaradialcrackalongtheinternalborewaspresentedinweightfunctionmethod.Theweightfumctionformulaswereworkedoutandcanbeusedforallkindsofdepthofcracks,rotatingspeed,material,sizeofthick-walledcylindertocalculatethestressintensityfactors.Theresultsindicatedthevalidityandeffectivenessoftheseformulas.Meanwhile,therulesofthestressintensityfactorsinrotatingthick-walledcylinderwiththechangeofcrackdepthsandtheratioofouterradiustoinnerradiuswerestudied.Thestudiesarevaluabletoengineeringapplication.

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简介：为semilinear的起始边界的值问题的答案的空间腐烂在易于侧面的边界上的零个条件的可变剖面图的半无限的柱体的寓言的方程被调查。秒顺序显示出空间腐烂O的微分不平等(exp(z2/(4(t+t0))))为L2p，答案的代表性的措施被获得。导致生长或腐烂的一阶的微分不平等也被导出。在生长的情况中，为在空间的发作的上面的界限被获得，当在腐烂的情况中为全部的精力的上面的界限以数据被获得时。

简介：经过有几何骚乱的方形节的柱体的流动被数字模拟调查。额外的条款，由于印射转变模仿的介绍，进转变Navier的骚乱的效果司烧方程，是正确地发源，并且在以前的文学的不正确的被指出并且分析。而且，在涡度之间的关系特别在柱体表面上，并且骚乱理论上被导出并且解释。计算与另一个目的在0.006，0.025和0.167的起浪的100和180和三个振幅的二个雷纳兹数字被执行在身体上在wake和力量在旋涡动力学上探索不同雷纳兹数字和骚乱的效果。数字结果证明了在0.025的温和起浪，流的Kármán旋涡为Re=完全被压制100，当强迫的旋涡脱臼被显得在时近在180的雷纳兹数字醒来。drag减小在Re=直到21.6%100和25.7%在Re=180为0.167的高起浪与非起浪的柱体相比。电梯和与不同雷纳兹数字和波浪险峻改变的Strouhal数字也被获得。

简介：AtheoreticalanalysisontheelectricdoublelayerformednearthesurfaceofaninfinitecylinderwithanellipticalcrosssectionandaprescribedelectricpotentialinanionicconductorwasperformedusingthelinearizedGouy–Chapmantheory.Asemi-analyticalsolutionintermsoftheMathieufunctionswasobtained.Thedistributionsoftheelectricpotential,cations,anions,andelectricfieldwerecalculated.Theeffectsofvariousphysicalandgeometricparameterswereexamined.Thefieldsvaryrapidlyneartheellipticalboundaryandarenearlyuniformatfarfield.Electricfieldconcentrationswerefoundattheendsofthesemi-majorandsemi-minoraxesoftheellipse.Theseconcentrationsaresensitivetothephysicalandgeometricparameters.

简介：DetaileddistributionsofheatfluxintheregionofshockwaveandturbulentboundarylayerinteractioninducedbyacylinderweremeasuredintheshocktunnelOilflowpatternsandSchlierenphoto-graphsweretaken.Empiricalrelationsweregivenfordeterminingseparationshockangle,peaksofheatfluxandtheirlocationsonbothcylinderleadingedgeandflatplatesurface,andothercharacteristicparametersoftheinteractionregion.

简介：Thegeometricaltheoryofdiffraction(GTD),combinedwithFouriertransformation,hasbeenappliedtotheback-scatteringonafinite-lengthrigidcircularcylinderduetoanarrowsoundbeam.Thetheoreti-calresultsareconfirmedbythemodelexperiment.

简介：Calculationofthescatteredfieldoftheeccentricscatterersisanoldproblemwithnumerousapplications.Thisstudyconsiderstheinteractionofaplanecompressionalsoundwavewithaliquid-encapsulatedthermoviscousfluidcylindersubmergedinanunboundedviscousthermallyconductingmedium.Thetranslationaladditiontheoremforcylindricalwavefunctions,theappropriatewavefieldexpansionsandthepertinentboundaryconditionsareemployedtodevelopaclosed-formsolutionintheformofinfiniteseries.Theanalyticalresultsareillustratedwithanumericalexampleinwhichthecompoundcylinderisinsonifiedbyaplanesoundwaveatselectedanglesofincidenceinawiderangeofdimensionlessfrequencies.Thebackscatteredfar-fieldacousticpressureamplitudeandthespatialdistributionofthetotalacousticpressureinthevicinityofthecylinderareevaluatedanddiscussedforrepresentativevaluesoftheparameterscharacterizingthesystem.Theeffectsofincidentwavefrequency,angleofincidence,fluidthermoviscosity,coreeccentricityandsizearethoroughlyexamined.Limitingcaseinvolvinganidealcom-pressibleliquid-coatedcylinderisconsideredandfairagreementwithawell-knownsolutionisestablished.

简介：话题在不同表面地里的球形的壳监禁下面的形成柱体的diblock共聚物(DBCP)自己组装用真实空间的前後一致的地理论计算(SCFT)被探索。用这条途径，我们在不同监禁尺寸和表面地观察了形成柱体的DBCP的各种各样的微观结构。从寻找详细说明microdomain形态学，一个明显的结论是在监禁之间的相互作用出现，聚合物穿上大效果自己组装。大多数微观结构大批或在平面、圆柱的监禁下面唯一、不报导。

简介：Thispapergivesthedirectivityfunctionofasectoralmul-ti-elementcylinderarray,analyzeitsphasefactor,explainindetailthesideloberejectionbyselectingthenumberofelements,bafflingandamplitudeweighting.Theyareparticularlyusefulfordirectionaltrackingofacousticalsignalandtargetlocating.