Abstract: Thermalandchemicalnonequilibriummodelingsstudywereperformedonalowpowernitrogen/hydrogenarcjet.Separateenergyequationswereformulatedfortheelectronsandtotalspecies,andsevenspeciesnitrogen/hydrogenplasmacompositionofmolecules,atoms,ionsandelectronswasassumed.Someimportantchemicalkineticprocessesofdissociationandionizationwereconsideredinthechemicalnonequilibriummodel.Theplasmapropertieswerecalculatedaccordingtothelocalspeciesnumberdensityandtemperature.Thedistributionoftemperatureandthenumberdensityofeachspeciesinthearcjetwereobtained.Theresultsshowthattheaxisofarcjetisclosetothermalequilibriumandsignificantdeviationfromthermalequilibriumisfoundinthearcattachmentregion.Itisshownthatthespeciesdistributionsofnitrogenandhydrogenaresignificantlydifferentfromthoseattheinletofthruster,whichindicatesthatthereexistthedemixingprocessesinsidethruster.Itisfoundthatthehydrogenspeciesdecreaseatfirstandthenincreasealongtheradialdirectionfromthecentertotheinnerwallofthruster,whilethenitrogencomponentsshowtheoppositetrend.Furtheranalysisshowsthatthespeciesdiffusionsinsidearcjetaredrivenbymolefractiongradientswhichareduetothedissociationandionizationofnitrogenandhydrogenspecies.

Key words: nitrogen/hydrogenarcjet, nonequilibrium, numericalsimulation, chemicalkinetics, electricpropulsion