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：BothexperimentalandnumericalinvestigationsontheflowpastacylinderundertheinfluenceofLorentzforce(electromagneticforce)wereconductedinanelectricallylow-conductingfluid.TheLorentzforceisappliedbothlocally,whollyandperiodicallyonthesurfaceofthecylinder,andtheircontroleffectsforflowseparationwereinvestigatedBothexperimentalandnumericalresultsshowthatLorentzforcecansuppresstheflowseparationwithLorentzforceappliedonbothlocalandwholesurfaceofthecylinder.However,whentheperiodicandoppositeLorentzforceadopted,thecylinderwakecannotbestabilized.

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：Toestimatethelifetimeofpneumaticcylinderinmachinetool(orautomaticassemblyline),newreliabilitymethodologyforparametricacceleratedlifetesting(ALT)issuggested.ItconsistsofparametricALTplan,generalizedlife-stressfailuremodelwithaneweffortconcept,accelerationfactor,andsamplesizeequation.ThisnewparametricALTenablesanengineertoestimatethelifetimeofacommerciallypartsbyuncoveringthefailurethroughacceleratedtestingundersevereconditions.Asacasestudy,twocommercialproductsofthepneumaticcylinderinmachinetoolweretested.ForcompanyA,wefoundthehardeningandwearofpistonseallikethatoffieldatnormalconditions.Asincreasingthepressure,thepneumaticcylindersweretested.Basedontheacceleratedconditions—0.8MPaand1.2MPaat23℃,B1lifeat0.63MPaand23℃wasextrapolatedas2.39×10^6.Ontheotherhand,forcompanyB,wefoundtherodcapblockedbyslurrylikethoseoffieldsamples.Basedontheacceleratedconditions—0.8MPaand1.4MPaat23℃,B1lifeat0.63MPaand23℃wasextrapolatedas2.51×10^6.Comparingthemwithtestingdataatnormaluseconditions,weknewthattheestimationerrorforbothcompanieswaslessthan10%.

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：Theaccuratecalculationandmeasurementofweldingtemperaturefieldisanimportantpreconditionforweldingmetallurgicalanalysisandweldingprocesscontrolling.Inthispaper,theconformaltransformationisfirstlyusedtoanalyzetheweldingtemperaturefieldoffeatheredgedcylinder.Thecenterofthecylinderischosenastheoriginofcolumncoordinatesystem,andeverypointmaybeexpressedascomplexfieldvector.Thebranchisogonalitycounterchangesthelineparallelwiththefusionlineinhalf-infinitez-planetothecircleconcentricwiththefusionlineininfinitecylinder.TheLaplaceequationandPoisson'sequationstillkeepvalidity,sothetemperaturefieldequationcanbesolved.TheconformaltransformationandequationsolutionisprocessedbyMatlabprogramlanguage.Itshowsthattheobtainedanalyticalmodelingoftemperaturefieldforfeatheredgedcylinderbasedonconformaltransformationiseffectiveandaccurate.

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：TheliftforcesonhorizontalcylindernearbottomisexperimentallyinvestigatdeatReynolds(Re)intherangelf2500~10000andKeulegan~CARPENTERNUMBERS(kc)intheintervalof5~20,andgapratio(e/D)isfrom(a0)areanalyzdebyusingtheFourieranalysesmethod.ItisfoundthatfoundthatbothCl&a0arethefunctionslftheKcnumber.

简介：Theflowbehindathree-dimensionalrotationallyoscillatingcircularcylinderwasstudiedbyanumericalmethod.ThecomputationswereperformedataReynoldsnumberof260,whichisatalevelthattheflowwakehasdevelopedintoathree-dimensionalstatecalledMode-B.Thepurposeofthispaperistoexaminetheinfluenceofvariousrotationalamplitudes(0.1-0.7)onthewakeinstabilityoftheflow,whiletheoscillationfrequencyisfixedtothevalueofthatmeasuredinthewakeofastationarycylinder.Theresultsshowthattherotationwithsufficientlyhighamplitudebringstheflowbacktoitsnominaltwo-dimensionalstate.Moreover,itisfoundthatthevalueofthetime-averageddragandtheRMSvalueoftheliftarelargerthanthoseofastationarycircularcylinder.

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

简介：Oscillatingflowaroundacircularcylinderinthevicinityofaplanewallwasinvestigatedbysolvingthetwo-dimensionalincompressibleNavier-StokesequationswithafiniteelementGalarkinresidualmethod.TheeffectofthegapGDbetweenthecylindersurfaceandthewallontheflowbehaviorwasstudied.ForthecaseofGD≤0.25,theperiodicityintheflowisattributedtoboththeoutershearlayerinstabilityandtheoscillatingfrequency.AsGD>0.25,vortexsheddingoccursandtheperiodicityintheflowismainlyduetothecompetitionoftheoscillatingfrequencyandthevortexsheddingfrequencyfromanisolatedstationarycylinder.

简介：为平衡4击的燃料注射调整的一个模型联合geneset的六台柱体柴油机引擎被在由机轴的速度变化的频率分析操作引擎检测不平衡开发。在这个工作，机轴被认为是僵硬身体，以便它的尖速度的变化能直接被相关到全部的煤气压力的转矩。由分析仅仅更低的泛音订单，速度变化光谱能滤出机轴的动态反应生产的失真。这些泛音订单带的信息允许建立在大小和引擎的平均煤气的压力转矩之间的关联，并且检测不平衡并且识别有缺点的柱体。详细说明的试验性的读在在护胫棉花有限公司Pune的测试床上联合genset的柴油机引擎上被拿，印度。

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

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

简介：Anewcollimationsystem,theheteroaxialdoublehalf-ellipticalcylinderlens(HDHECL),isproposedbasedontheraytracingmethod,andthecollimationperformanceoftheHDHECLisdiscussedandcomparedwithconventionallenses.ThesimulationresultssuggestthattherefractiveindexoftheHDHECLcanbelargerthan2,thecollimationeffectisimprovedwiththeincreaseoftherefractiveindexinacertainrange,andthedivergenceangleinthefast-axisdirectioncanbecompressedtolessthan0.01mradtheoretically.Theseresultsareofsignificanceintheoryandpractice.

简介：由于胭脂波浪的物理机制的复杂性，rogue-wavestructure相互作用问题的理论学习仍然取得很少进步。为常规形状的结构，然而，给理论分析是可能的，如果流氓波浪的一个相对简单的模型被使用。波浪负担，由作为胭脂波浪的一个直觉的基本模型被知道的一个集中的波浪导致了，在沉没半的柱体之上被学习经分解。集中的波浪由高斯信封波浪是近似的，包含流氓波浪的大多数特征的一个理想的模型。衍射速度潜力通过水平力量的流动地，和公式的分离被导出，弯曲时刻被建议。导出的公式适当地被简化，并且对数字结果通过比较验证了。另外，参数的影响集中的沉没深度和波浪例如集中的度，放，彻底地被调查。

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