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

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：Dependenceofthecurrent-voltagecharacteristicsofanon-transferredDCcascadedplasmatorchusedfornanoparticlesynthesis,ontheplasmacurrentandtheplasmaargongasflowratearereportedinthispaper.Thepotentialstructureinsidethetorchanditsdependenceontheplasmacurrentandgasflowratearealsoinvestigated.Thearcvoltageisseentoexhibitnegativecharacteristicforacurrentbelow150Aandpositivecharacteristicabovethatcurrentvalue.Thevoltagedropneartheelectrodesisfoundtodecreasewiththeincreaseinplasmacurrent.25%ofthetotalvoltageisdroppednearthecathodeataplasmacurrentof50Aandaargonplasmagasflowrateof10literperminute(LPM),anditdecreasesto12%withthecurrentincreasingto300A,andto17%withagasflowrateof25LPM.Thevariationinthetorchefficiencywiththegasflowrateandplasmacurrentisalsoreported.Theefficiencyofthetorchisfoundtobebetween36%and48%.Inaddition,theplasmagastemperatureatvariouspositionsofthereactorandfordifferentcurrentsandvoltagesaremeasuredbycalorimetricestimationwithaheatbalancetechnique.

简介：Toexploretheeffectofthegassourceflowrateontheactualdieselexhaustparticulatematter(PM),atestbenchfordieselengineexhaustpurificationwasconstructed,usingindirectnonthermalplasmatechnology.Theeffectsofdifferentgassourceflowratesonthequantityconcentration,composition,andapparentactivationenergyofPMwereinvestigated,usinganengineexhaustparticlesizerandathermo-gravimetricanalyzer.Theresultsshowthatwhenthegassourceflowratewaslarge,notonlythemaximumpeakquantityconcentrationsofparticleshadalargedrop,butalsothepeakquantityconcentrationsshiftedtosmallerparticlesizesfrom100nmto80nm.Whenthegassourceflowratewas10Lmin~(-1),thetotalquantityconcentrationgreatlydecreasedwheretheremovalrateofparticleswas79.2%,andthevariationofthedifferentmodeparticleproportionwasobvious.Non-thermalplasma(NTP)improvedtheoxidationabilityofvolatilematteraswellasthatofsolidcarbon.However,theNTPgassourceratehadlittleeffectsonoxidationactivityofvolatilematter,whileitstronglyinfluencedtheoxidationactivityofsolidcarbon.Consideringthequantityconcentrationandoxidationactivityofparticles,agassourceflowrateof10Lmin~(-1)wasmoreappropriateforthepurificationofparticles.

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