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简介：Numericalsimulationsareperformedforlaminarnaturalconvectionheattransferfromacenteredconductingbodyenclosedinasquarecavity.Ahighaccuracyunsteadynumericalmethodisused,combiningtheuniqueconditionofthepressure,theconvergentsolutionsandthestream-functionvalueoftheinsideheat-conductingbodyaregivensimultaneously.Twoexamplesaresimulatedwiththisnumericalmethodandcomparedwiththeexperimentalresults.Theresultsofthenumericalsolutionsareconsistentwiththeexperimentalresults.Itshowsthatthenumericalmethodisvalidandfeasible.

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简介：Nonlinearwaveloadscaninducelow-frequencyandhigh-frequencyresonancemotionsofamooredplatformindeepwater.Fortheanalysisofthenonlinearresponseofanoffshoreplatformundertheactionofirregularwaves,themostwidelyusedmethodinpracticeistheCumminsmethod,inwhichthesecond-orderexcitingforcesinthetimedomainarecomputedbyatwo-termVolterraseriesmodelbasedonincidentwaves,first-orderbodymotionresponse,andquadratictransferfunctions(QTFs).QTFsarebichromaticwavesactingonabodyandarecomputedinthefrequencydomaininadvance.Formovingbodies,QTFsarerelatedtothefirst-orderbodyresponse,whichistobedeterminedinthesimulationprocessofbodymotionresponsebutisunknowninthecomputationprocedureofQTFs.Insolvingthisproblem,TengandCong(2017)proposedamethodtodividetheQTFsintodifferentcomponents,whichareunrelatedtothebodyresponse.WiththeapplicationofthenewQTFcomponents,amodifiedCumminsmethodcanbedevelopedforthesimulationofthenonlinearresponseofamooredfloatingplatform.Thispaperpresentsareviewofthetheory.

简介：Thepaperbuildsamulti-rigid-bodymodelofhumanwitha4-rigid-bodyfootinthe3DCADsoftwareSolidworks,basedonhumananatomy.Bycontrollingtherotationoftheankleandmajorjointsofhumanbodywhilewalking,theKinematicsimulationwasperformedinthedynamicssimulationsoftwareADAMS.Thepaperanalyzesthesimulateresultsandpointsoutdeficienciesinthecurrentworkandthedirectionofresearcheffortsinfuture.

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简介：AnovelnumericalmodelbasedontheimageGreenfunctionandfirst-orderTaylorexpansionboundaryelementmethod(TEBEM),whichcanimprovetheaccuracyofthehydrodynamicsimulationforthenon-smoothbody,wasdevelopedtocalculatethesidewalleffectsonfirst-ordermotionresponsesandsecond-orderdriftloadsuponoffshorestructuresinthewavetank.Thismodelwasconfirmedbycomparingittotheresultsfromexperimentsonhydrodynamiccoefficients,namelythefirst-ordermotionresponseandsecond-orderdriftloaduponahemisphere,prolatespheroid,andbox-shapedbargeinthewavetank.Then,thehydrodynamicsoftheKVLCC2modelwerealsocalculatedintwowavetankswithdifferentwidths.Itwasconcludedthatthismodelcanpredictthehydrodynamicsforoffshorestructureseffectively,andthesidewallhasasignificantimpactonthefirstorderquantitiesandsecond-orderdriftloads,whichsatisfiedtheresonantrule.

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简介：Nucleon-nucleon(NN)correlationsandtheirisospindependenceinasymmetricnuclearmatterareofgreatnterestsincetheyarecloselyrelatedtothestructureofneutron-richnuclei[1],particleproductioninheavy-ionollisions[2],andneutron-starphysics[3].Themany-bodycorrelationsamongnucleonscanbedirectlyreflectedintheneutronandprotonspectralfunctions[4],andthelattermayplayanimportantroleinunderstandingthenatureftheNNcorrelations,especiallytheshort-rangeandtensorcorrelationsinasymmetricnuclearmatter.

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简介：Theobjectiveofthisinvestigationistoexaminethecorrectnessandefficiencyofthechoiceofboundaryconditionswhenusingassumedmodeapproachtosimulateflexiblemulti-bodysystems.ThedisplacementfieldduetodeformationisapproximatedbytheRayleigh-Ritzassumedmodesinfloatingframeofreference(FFR)formulation.Thedeformationsobtainedbytheabsolutenodalcoordinate(ANC)formulationwhicharetransformedbytwosetsofreferencecoordinatesareintroducedasacriteriontoverifytheaccuracyofthesimulationresultsbyusingtheFFRformulation.Therelationshipbetweenthedeformationsobtainedfromdifferentboundaryconditionsisrevealed.Numericalsimulationexamplesdemonstratethattheassumedmodeswithcantilevered-free,simply-supportedandfreefreeboundaryconditionswithoutinclusionofrigidbodymodesaresuitableforsimulationofflexiblemulti-bodysystemwithlargeoverallmotion,andthesamephysicaldeformationcanbeobtainedusingthosemodefunctions,differonlybyacoordinatetransformation.Itisalsoshownthatwhenusingmodeshapeswithstaticallyindeterminateboundaryconditions,significanterrormayoccur.Furthermore,theslidercrankmechanismwithrigidcrankisaccurateenoughforinvestigatingboundaryconditionproblemofflexiblemulti-bodysystem,whichcostsignificantlesssimulatingtime.

简介：Thedynamicbucklingofanelastic-plasticcolumnsubjectedtoaxialimpactbyarigidbodyhasbeendiscussedinthispaper.Thewholetravelingprocessofelastic-plasticwavesunderimpactactionisanalyzedwiththecharacteristicsmethod.Theregularityofstresschangesinbothcolumnendsandthefirstseparatingtimeofarigidbodyandcolumnareobtained.Byusingtheenergyprincipleandtakingintoaccountthepropagationandreflectionofstresswavesthelateraldisturbanceequationisderivedandthepowerseriessolutionisgiven.Inaddition,thecriticalbucklingconditioncanbeobtainedfromthestabilityanalysisofthesolution.Bynumericalcomputationandanalysis,therelationshipamongcriticalvelocityandimpactmass,hardeningmodulus,andbucklingtimeisgiven.

简介：BasedontheFloquettheoryonordinarydifferentialequationswithperiodicallyvariablecoefficientsandthebifurcationapproachtononlinearequations,anumericalapproachtodeterminingthestabilityregionofcontrolparametersisestablishedforadynamiccontrolsystemcomposedofamovingbodylevitatedmagneticallyoverflexibleguideways.Thesystemisnonlinearlycoupledamongtheelasticdeformationofguideways,disturbancethelevitationpositionofthebodyandelectromagneticcontrolforces.Thenumericalsimulationisgivenforthesysteminthecaseinwhichthecontrolparametersaretakenwithinandoutofthestabilityregionrespectively.Resultsshowthatthisapproachisreliable.

简介：Laminarheattransferproblemisanalyzedforadiskrotatingwiththeangularspeedωinaco-rotatingfluid(withtheangularspeedΩ).Thefluidisswirledinaccordancewithaforced-vortexlaw,itrotatesasasolidbodyatβ=Ω/ω=const.Radialvariationofthedisk’ssurfacetemperaturefollowsapowerlaw.Anexactnumericalsolutionoftheproblemisobtainedbasingontheself-similarprofilesofthelocaltemperatureoffluid,itsstaticpressureandvelocitycomponents.NumericalcomputationsweredoneatthePrandtlnumbersPr=1(?)0.71.Itisshownthatwithincreasingβbothradialandtangentialcomponentsofshearstressesdecrease,andtozerovalueatβ=1.Nusseltnumberispracticallyconstantatβ=0(?)0.3(andevenhasapointofamaximuminthisregion);Nudecreasenoticeablyforlargerβvalues.

简介：可以为灵活身体的大变丑引起液体格子失真，它将使数字计算乏味，甚至到结束，结合液体的灵活身体的数字模拟总是是一个坚韧的问题。在这份报纸，灵活身体在二种抑制条件下面，长度直径的比率是1:30。气流的雷纳兹数字是513，属于低雷纳兹数字的区域。与气流联合灵活身体的控制方程被造，适应格子控制方法被采用进行灵活身体的运动的三维的数字模拟。数字结果证明在低雷纳兹数字气流模仿灵活身体运动的特征是可能的适当控制方程什么时候被建模，合适的解决方程的方法被采用。当流动域里的抑制灵活身体将沿着灵活身体的轴做周期的旋转运动时，非强迫的灵活身体将沿着气流散开方向向前翻，并且弯曲变丑比非强迫的灵活身体的更明显。初步的三维的数字模拟能在高级雷纳兹数字气流为关于纱运动的特征的进一步的研究提供参考书。

简介：Open-loopflowcontrolmethodwasusedtoaffectthedevelopmentofaturbulentwakebehindaD-shapedbluffbody.Loudspeakerswereembeddedinsidethebluffbodytoproducetwozero-net-massfluxjetsthrough2mm-widespan-wiseslotslocatedalongtheupperandloweredgesontherearwall.Thedragforcesfordifferentactuationamplitudes(C_μtheratiobetweenthemomentumoftheactuatingjetsandthemomentdeficitcausedbythebluffbody)andfrequencies(Sr_A)wereexamined.Theeffectsofthephasedifferenceinthetwojets(0andπ)werealsostudied.ItwasfoundthatwhenC_μwas0.1%,adragreductionupto5%wasachievedwhenthevelocitiesofthetwojetsvariedinphaseatafrequencyofSt_A=0.16.Whenthevelocitiesofthetwojetsvariedrroutofphase,significantdragincreasewasobserved.

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简介：Thispaperstudiesthewall-boundedflowaroundacylindricalatahighReynoldsnumbersbodyinadeterminedcomputationaldomain,withsimulationsofthe3-D,turbulentconcentricannulusflowinastraightpipe.Numericalresultsshowthatareversingzone,appearingasatonguezonewithnestedvelocitieshigherthanthesurroundingarea,existsbehindthecylindricalbody.Theannulusspaceisaregionofhighvelocityandlowpressure.Thezerovelocity,ofcombinedtheX-velocityandtheY-velocity,existsinthecrosssectionsandnovortexsheddingisformedbehindtheattachingcylinders.Amongallinvestigatedeffectingfactors,thediametersoftheattachingandthemaincylindersaffectthewakefeaturebehindthecylindricalbodywhilethemaincylinderlengthdoesnotaffectthedistributiontendencyoftheflowfield.Thediametersofthemaincylinderandthepipeaffectthepressurevaluesandthedistributiontendenciesonthemaincylindersurface.Obviously,theincreaseofthepipediameterreducesthedragcoefficientofthecylindricalbodyandtheincreaseofthediameterofthemaincylinderincreasesthedragcoefficientgreatly.Thenumericalinvestigationoftheconcentricannulusflowprovidesfoundationsforfurtherimprovementsoftheintricateflowstudies.