简介：Energydepositionofintensepulsedionbeam(IPIB)ontheTitargetbasedonthe2DmodelofIPIBdensityhasbeensimulatedbytheMonteCarlo(MC)method.Takingthedepositedenergyasthethermalsource,wehaveestablishedtheablationmodelofthetargetandcalculatedthespatialandtemporalevolutionoftheablationshapeoftheTitargetirradiatedbyIPIBwithdifferentenergydensities.WehavealsoestablishedtheejectionmodelofthehydrodynamicequationsrelatedtotheablationshapeofthetargetbyusingtheablationresultsastheinitialconditionsofplasmaformedbyIPIBirradiation.Thespatiallyandtemporallyevolutedprofilesoftheplasmapressureandmassdensityarecalculated.

简介：An8-channelHCNlaserinterferometerwillbeinstalledonHL-2Ainnearterm.InordertogetthespatialprofileoftheelectrondensityBarrnumericalmethodisadoptedtorealizetheAbelinversion.InthisarticletheresultoftheAbelinversionbyMatlabGUIisgivenwhichcanbeupdatedtoprocessthemeasureddataofthe8-channellaserinterferometerandprovidethespatialdistributionoftheelectrondensity.

简介：Numericalsimulationsbasedonthefinite-difference-time-domain(FDTD)approximationtomulti-fluidequationsforpositiveions,negativeionsandelectronsareusedtostudyhighfrequencyelectromagneticwavepropagationandabsorptioninanunmagnetizedplasmalayer.Theinteractionbetweentheincidenthighfrequencywaveandtheplasmalayershowsthattheexistenceofnegativeionsandthenonlineareffectreducesthepowerabsorptioncapabilityoftheplasma.Parameterdependencesoftheeffectsarecalculatedanddiscussed.

简介：Magnetohydrodynamic(MHD)acceleratorisproposedasanextgenerationpropulsionsystem.Itcanbeusedtoincreasetheperformanceofapropulsionsystem.TheobjectiveofthisstudyistoinvestigatetheperformanceofMHDacceleratorusingnon-equilibriumairplasmaasworkinggas.Inthisstudy,thefundamentalperformanceofMHDacceleratorsuchasflowperformanceandelectricalperformanceisevaluatedatdifferentlevelsofappliedmagneticfieldusing1-Dnumericalsimulation.ThenumericalsimulationisdevelopedbasedonasetofdifferentialequationswithMHDapproximation.TosolvethissetofdifferentialequationstheMacCormackschemeisused.AspecifiedchanneldesignedanddevelopedatNASAMarshallSpaceFlightCentreisusedinthenumericalsimulation.Thecompositionofthesimulatedairplasmaconsistsofsevenspecies,namely,N2,N,O2,O,NO,NO+,ande-.Theperformanceofthenon-equilibriumMHDacceleratorisalsocomparedwiththeequilibriumMHDaccelerator.

简介：Numericalsimulationsof10kWand110kWinductivelycoupledplasma(ICP)windtunnelswerecarriedouttostudyphysicalpropertiesoftheflowinsidetheICPtorchandvacuumchamberwithairastheworkinggas.Two-dimensionalcompressibleaxisymmetricNavierStokes(N-S)equationsthattookintoaccount11speciesand49chemicalreactionsofair,weresolved.Aheatsourcemodelwasusedtodescribetheheatingphenomenoninsteadofsolvingtheelectromagneticequations.Inthevacuumchamber,afour-temperaturemodelwascoupledwithN-Sequations.Numericalresultsforthe10kWICPwindtunnelarepresentedanddiscussedindetailasarepresentativecase.Itwasfoundthattheplasmaflowinthevacuumchambertendedtobeinlocalthermochemicalequilibrium.Tostudytheinfluenceofoperationconditionsontheflowfield,simulationswerecarriedoutfordifferentchamberpressuresand/orinputpowers.ThecomputationalresultsfortheabovetwoICPwindtunnelswerecomparedwithcorrespondingexperimentaldata.Thecomputationalandexperimentalresultsagreewell,thereforetheflowfieldsofICPwindtunnelscanbeclearlyunderstood.

简介：Ahigh-currentvacuumarc(HCVA)withtheconsiderationofanodevaporismod-eledandsimulated.First,fromtheHCVAcolumnmodel,theheatfluxdensitytotheanodeisobtained,whichisputintotheanodeactivitymodel,andtheparameterdistributions(suchasthevaportemperatureandvelocity)ofanodevaporareobtainedfromthesimulationresultsoftheanodeactivitymodel.Then,byiteratingandcalculatingtheHCVAcolumnmodelandanodeactivitymodel,theinteractionbetweentheHCVAcolumnandtheanodevaporissimulatedandanalyzed.Inthesimulation,thedistributionoftheaxialmagneticfield(AMF)generatedbytheelectrodesystemiscalculatedbysoftwareANSYS.Thesimulationresultsshowthattheinfluenceofanodevaporontheparameterdistributionsinthearccolumnissignificant.Thesimulationresultsarealsocomparedwiththevacuumarcphotograph.

简介：Inthiswork,wesimulatenumericallythethermaleffectsinnitrogenatatmosphericpressurecausedbyanegativecoronaDCdischargeoflowcurrent.Amathematicalfunctionthatsimulatestheinjectionofthethermaltransferingasisproposed.Thesimulateddischargeisofanegativepointtoplanemasstype,withaninterelectrodedistanceof12mmandasymmetryabouttheaxisofdischarge.Thespatialandtemporalevolutionofneutralsisanalyzedbasedupontheequationsofcontinuity,momentumandenergyinacylindricalgeometry.Forthegeometryofthesystem,theFCT(fluxcorrectedtransport)procedurewasadopted.

简介：Tounveilthecharacteristicsandavailablepropagationmechanismofcoaxial-typemicrowaveexcitedline-shapeplasma,theeffectsofparametersincludingmicrowavepower,workingpressure,dielectricconstant,andexternalmagneticfieldontheplasmadistributionwerenumericallyinvestigatedbysolvingacoupledsystemofMaxwell’sequationsandcontinuityequations.Numericalresultsindicatethathighmicrowavepower,relativelyhighworkingpressure,lowdielectricconstant,andshapedmagneticfieldprofileswillhelpproduceahigh-densityanduniformplasmasource.Excitingbothendsbymicrowavecontributedtothehigh-densityanduniformplasmasourceaswell.Possiblemechanismswereanalyzedbyusingthepolarizationmodeloflowtemperatureplasma.Thegenerationandpropagationprocessesoftheline-shapeplasmamainlydependontheinteractionofthreeaspects,i.e.thetransmittedpart,penetrationpartandabsorptivepartoftheelectromagneticfield.Thenumericalresultswerequalitativelyconsistentwithavailableexperimentalresultsfromliterature.Moreelaboratedescriptionsofthethreeaspectsandcorrespondinginteractionsamongthemneedtobeinvestigatedfurthertoimprovethepropertiesoftheline-shapeplasma.

简介：Thecharacteristicsofhomogeneousdischargesinmixedgasesofhydrogendilutedsilaneandargonatatmosphericpressureareinvestigatednumericallybasedonaone-dimensionalfluidmodel.Thismodeltakesintoaccounttheprimaryprocessesexcitationandionization,sixteenreactionsofradicalswithradicalsinsilane/hydrogen/argondischargesandtherefore,canadequatelyrepresentthedischargeplasma.Weanalyzetheeffectsofveryhighfrequency(VHF)onthedensitiesofspecies(e,H,SiH3,SiH+3andSiH2)insuchdischargesusingthemodel.ThesimulationresultsshowthatthedensitiesofSiH3,SiH+3,H,andSiH2increasewithVHFwhentheVHFrangesfrom30MHzto150MHz.Itisfoundthatthedepositionrateofμc-Si:HfilmdependsontheconcentrationofSiH3,SiH+3,SiH2,andHintheplasma.TheeffectsofVHFonthedepositionrateandtheamountofcrystallizedfractionforμc-Si:Hfilmgrowthisalsodiscussedinthispaper.

简介：Anumericalsimulationmodelfor252kVpuffercircuitbreakerisconstructed,byusingaprovencommercialcomputationalfluiddynamics（CFD）package,PHOENICS.Themodeltakesintoaccountthemovingpartsinthecircuitbreaker,turbulenceenhancedmomentumandenergytransport,radiationtransport.ThearcingprocessinaSF6puffercircuitbreakerwithtwohollowcontactsissimulatedunderdifferentconditions,andthesimulationresultsareverifiedwithexperimentalresults.Throughsimulation,thepressure,temperatureandvelocityinthearcquenchingchambercanbeobtained.Thesimulationmodelisalsocapableofpredictingtheinfluenceofdesignparametersvariationsonbreakerperformance,andcanthushelptoreducethenumberofshort-circuittestsduringthedesignstage.

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简介：A1-Dfluidmodelforhomogeneousdielectricbarrierdischarge(DBD)inheliumispresented,aimedatunravelingthespatial-temporalcharacteristicsoftwobasicdischargeregimes:single-breakdownandmulti-breakdowndischarges.Dischargecurrents,gapvoltages,chargedensities,electrontemperatureandelectricfieldprofilesofthetworegimesmakeitclearthatthesetworegimesarequalitativelydifferent.Itisfoundthatthemulti-breakdowndischargehasamorehomogeneousfluxondielectricscomparedtothesingle-breakdowndischarge.

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简介：Inordertoinvestigatetheinjectioncurrentuniformityaroundtheinductioncellbores,twofullyelectromagnetic(EM)modelsarerespectivelyestablishedforasingle-stageinductioncellandaninductionvoltageadder(IVA)withthreecellsstackedinseries,withoutconsideringelectronemission.Bymeansofthesetwomodels,somefactorsaffectingtheinjectioncurrentuniformityaresimulatedandanalyzed,suchastheimpedancesofaddersandloads,celllocations,andfeedtimingofparalleldrivingpulses.Simulationresultsindicatethathigherimpedancesofadderandloadsareslightlybeneficialtoimproveinjectioncurrentuniformity.Astheimpedancesofadderandloadsincreasefrom5Ωto30Ω,theasymmetriccoefficientoffeedcurrentsdecreasesfrom10.3%to6.6%.Thecurrentnon-uniformitywithinthefirstcellisalittleworsethanthatinotherdownstreamcells.Simulationresultsalsoshowthatthefeedtimingwouldgreatlyaffectcurrentwaveforms,andconsequentlycausesomedistortioninpulsefrontsofcelloutputvoltages.Foragivendrivingpulsewithdurationtimeof70-80ns,thefeedtimingwithatimedeviationoflessthan20nsisacceptableforthethree-cellIVAs,justcausingtherisetimeofoutputvoltagestoincreaseabout5nsatmostandmakingthepeakvoltagedecreaseby3.5%.

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简介：Athreedimensionalsteady-statemagnetohydrodynamicmodelisdevelopedforthearcplasmainaDCsubmergedelectricarcfurnacefortheproductionoffusedMgO.Thearcisgeneratedinasmallsemi-enclosedspaceformedbythegraphiteelectrode,themoltenbathandunmeltedrawmaterials.Themodelisfirstusedtosolveasimilarprobleminasteelmakingfurnace,andthecalculatedresultsarefoundtobeingoodagreementwiththepublishedmeasurements.ThebehaviorofarcswithdifferentarclengthsisalsostudiedinthefurnaceforMgOproduction.Fromthedistributionofthearcpressureonthebathsurfaceitisshownthatthearcplasmaimpingementislargeenoughtocauseacrater-likedepressiononthesurfaceoftheMgObath.Thecirculationofthehightemperatureairundertheelectrodemayenhancethearcefficiency,especiallyforashorterarc.

简介：Interactionbetweenhigh-intensitypulsedionbeam(HIPIB)andadouble-layertargetwithtitaniumfilmontopofaluminumsubstratewassimulated.Thetwo-dimensionalnonlinearthermalconductionequations,withthedepositedenergyinthetargettakenassourceterm,werederivedandsolvedbyfinitedifferentialmethod.Asaresult,thetwo-dimensionalspatialandtemporalevolutionprofilesoftemperaturewereobtainedforatitanium/aluminumdouble-layertargetirradiatedbyapulseofHIPIB.Theeffectsofionbeamcurrentdensityonthephasestateofthetargetmaterialsnearthefilmandsubstrateinterfacewereanalyzed.BothtitaniumandaluminumweremeltedneartheinterfaceaRerashotwhentheionbeamcurrentdensityfellintherangeof100A/cm~2to200A/cm~2.