辐流式二沉池固液两相流数值模拟屈强

:2005-06-20:“”(2002AA601270);(042312067);:　(1975-),,,.E-mail:[e-mail]屈　强,马鲁铭,王红武(,　200092):k-ε(-),.RNG()k-εMixture(),.:,20%.,1.2m,,,0.1m..:;;:X703.1　　　　　　:A　　　　　　:0253-374X(2006)09-1212-05Solid-LiquidTwo-PhaseFlowSimulationinaCircularSecondaryClarifierQUQiang,MALuming,WANGHongwu(StateKeyLaboratoryofPollutionControlandResourceReuse,TongjiUniversity,Shanghai200092,China)Abstract:Conventionalmethodswhichadoptsstandardk-εmodeltosimulatetwo-phaseflowinasecondaryclarifierleadtoinaccurateresults.Inthispaper,theimprovedRNGk-εtwo-equationmodelandthesimplifiedmultiphaseMixturemodelareusedtosimulatethefluidvelocitydistributionandsludgevolumefractioninacircularclarifier.Resultsindicatethattwodeadzones,whichoccupy20%oftheclarifier'svolume,existinthesurfaceandbottom.Compressioninterfaceandobvioushorizontalsludge-waterinterfacewhichis1.2mbelowwatersurfacearefound;themajorpartofthesludgeblanketislamellazone.Thebottomofthesludgeisacompressionalzonewithhighsludgeconcentra-tionandthethicknessisnotmorethan0.1m.Dataareingoodagreementwithrealresults.Keywords:circularclarifier;two-phaseflow,numericalsimulation　　,,.Anderson[1,2]:、、,,,.Krebs[3,4][5]k-ε[6,7],.34920069()JOURNALOFTONGJIUNIVERSITY(NATURALSCIENCE)Vol.34No.9　Sep.2006[8,9].,k-ε,、、,,[10].,k-ε,RNGk-ε.,,.,RNGk-εMixture,.1　,,,,、.,[11].Mixture,,、,.,[12].Mixturet(ρk)+Δ(ρmvm)=m·(1)vm=∑nk=1αkρkvkρm(2)ρm=∑nk=1αkρk(3)(1)～(3):ρkk;ρm,vm;vkk;αkk;m·.Mixture,　　　t(ρmvm)+Δ(ρmvmvm)=-Δp+　　　　Δ[μm(Δvm+vTm)]+ρmg+F+　　　　Δ∑nk=1αkρkvdr,rvdr,k(4):n;F;g;μm,μm=∑nk=1αkμk(5)　　vdr,kk,vdr,k=vk+vm(6)　　pqvqp=vp-vq(7)　　vdr,p=vqp-∑nk=1αkρkρmvqk(8)　　pt(αpρp)+Δ(αpρpvm)=-Δ(αpρpvdr,p)(9)　　,,k-ε,.k-ε,,、,k-ε,RNGk-ε[13],,,.,kεuikxi=xiμ+μtσkkxi+Pk-ε(10)uiεxi=xiμ+μtσεεxi+　　Cε1εkPk-Cε2ε2k(11):μ;μt;Pk=μtuixjuixj+ujxi;σk=0.7179;σε=0.7179;Cε1=1.42-η(1-η/η0)1+βη3,η=Sk/ε,S=(Sij,Sij)1/2,Sij=12uixj+ujxi,η0=4.38,β=0.012～0.015;Cε2=1.68.1213　9　,:　　,RNGk-εk-ε.2　4.0m,2.0m,,,,,,[4].,1.R,Q.1　Fig.1　Geometryofcirculartank　　3.4kg·m-3,0.86,1.9cm·s-1,,,,,[15].,,,,.,Simplec,、、Quick,24417,FLUENT6.1.,,,,,,,,.3　2,.3,.2　Fig.2　Sludgeconcentrationfieldincircularclarifier3　Fig.3　Streamlinesincircularclarifier　　4,4a～f3,6,9,12,15,18m.2,,1.2m,,,,,,,0.1m,,,,[16],[17].3,1,20%,,,1214　　　()34　.,.4,,,,,;.3m,,6m9m,,,,,.4　Fig.4　Velocitydistributionincircularclarifier4　RNGk-εMixture,Simplec,Fluent6.1,.:,,,,.,,.:[1]　AndersonNE.Designofsettlingtanksforactivatedsludge[J].SewageWorksJournal,1945,17(1):50.[2]　BretscherU,KrebsP,HagerWH.Improvementofflowinfinalsettlingtanks[J].JournalofEnvironmentalEngineering,ASCE,1992,118(3):307.[3]　KrebsP,ArmbrusterM,RodiW.Laboratoryexperimentsofbuoyancy-influencedflowinclarifiers[J].JournalofHydraulic　Research,1998,36(5):831.[4]　KrebsP,StamouAI,Garcia-Heras.Influenceofinletandoutletconfigurationontheflowsecondaryclarifiers[J].WaterScienceandTechnology,1996,34(5-6):1.[5]　LynDA,StamouAI,RodiW.Densitycurrentsandshear-inducedflocculationinsedimentationtanks[J].JournalofHy-draulicEngineering,1992,118(6):849.[6]　TakacsI,PatryG,NlascoD.Adynamicmodeloftheclarification-thickeningprocess[J].WaterResearch,1991,25(10):1263.[7]　ZhouS,McCorquodaleJA.Modelingofrectangularsettlingtanks[J].JournalofHydraulicEngineering,1992,118(10):1391.[8]　,,,.[J].,2002,22(4):338.　　　ZENGGuangming,GEWeihua,QINXiaosheng.Numericalsim-ulationofcurrentandsolidsinsecondarysedimentationtanksinwastewatertreatmentplant[J].ChinaEnvironmentalScience,2002,22(4):338.[9]　,,,.[J].,2002,20(4):10.　　　ZENGGuangming,GEWeihua,QINXiaosheng.Applicationofnumericalsimulationinsecondarysedimentationtankdesign[J].EnvironmentalEngineering,2002,20(4):10.[10]　.[M].:,2002.　　　ZHOULixing.Fluiddynamicsofmultiphaseturbulencereaction[M].Beijing:DefenseIndustryPress,2002.[11]　,.-[J].,2001,52(1):1.1215　9　,:　　　　　ZHANGZheng,XIEZhuoli.Numericalsimulationoffluid-solidtwophaseflow[J].ChemicalEngineeringJournal,2001,52(1):1.[12]　FluentInc.Fluentdocumentation[R].[s.l.]:FluentInc,2003.[13]　YakhotV,SmithLM.Therenormalizationgroup———theex-pansionandderivationofturbulencemodels[J].JournalofSci-enceComputing,1992,7(1):31.[14]　DjamelLakehal,PetrKrebs.Computingshearflowandsludgeblanketinsecondaryclarifiers[J].JournalofHydraulicEngi-neerlng,1999,125(3):253.[15]　LaunderBE,SpaldingDB.Thenumericalcomputationoftur-bulentflows[J].ComputerMethodsinAppliedMechanicsandEngineering,1974(3):269.[16]　,.[M].:,1999.　　　GAOTingyao,GUGuowei.Waterpollutioncontrolengineering[M].Beijing:HigherEducationPress,1999.[17]　,.[J].,1988,4(2):16.　　　MALuming,GAOTingyao.OperatingmodeinvestigationofsecondarysedimentationtanksinShanghaimunicipalwastewaterplants[J].ChinaWaterandWastewater,1988,4(2):16.(编辑:张　弘)(1169)[3]　,.[J].,1999,17(6):180.　　　YUWeizhong,WANGGaoming.Corrosioninvestigationandre-pairofhydraulicreinforceconcretestructureinamarineenviron-ment[J].Hydro-ScienceResearch,1999,17(6):180.[4]　,.[J].,2000,25(5):27.　　　YANGHuashu,CHUFutao.Debatingabouttwoelementalproblemsofagingevaluationofhydraulicconcreteconstruction[J].JournalofKunmingUniversityofScienceandTechnology,2000,25(5):27.[5]　,.[J].,2002,18(2):1.　　　YANGLinde,GA