简介：Multiphaseflowcontrolwithelectromagneticbraking(EMBr)iswidelyusedinthecontinuouscastingofsteelslabs.Thebasicaimoftheflowcontrolsystemoftheprocessistodelivermoltensteelfromtheladlethroughthetundish,uppertundishnozzle,slidegate,andsubmergedentrynozzleintothemoldregionwithminimaldefects.Thisrequirestheoptimizationofturbulencelevelsatameniscustoavoidbothanexcessivelyfastflow(whichcreateshighfluctuationsofthemeniscuslevelinadditiontoslagentrapment,surfacenonuniformities,andsurfacedefects)andinsufficientslowflow(whichleadstomeniscussolidification,inadequatefluxinfiltration,andsurfacedefects).Inthisstudy,aEulerian-LagrangianapproachisusedtoinvestigatetheeffectsofEMBrandArbubbleinjectiononthesurfaceflowvelocity.TheresultsshowthathighArinjectionratescanleadtoanincreaseinsurfacevelocity.

简介：Unsteadyfluidflowsandlevelfluctuationsinathinslabcontinuouscastingmouldhavesignificantinfluenceonproductquality.Inthisstudy,thephenomenaconcerningtransientflowfeaturesandfreesurfacemotionswereanalyzedbymeansofthelargeeddysimulation(LES)softwarewiththesmagorinskySGSmodel-VisualCast(VCast)II,wheretheSimpleralgorithmonabody-fittedmeshwasusedtoresolvegoverningequations.Aseriesofwateranalogexperimentsonthefluidflowandthesurfacewaveinthemouldsofthinslabcontinuouscastingwerealsoperformed.Theresultsoffluidregions,middleofvortexandlevelfluctuationfromdigitalsimulationswereidenticalwiththeresultsofthewateranalogexperiments.

简介：Thisstudyestablishedathree-dimensionalmathematicalmodeltodeterminethefluidflowinaslabcontinuouscastingmoldunderanelectromagneticstirringforce.Theflowstructureanddistributionwerestudiedwithrespecttodifferentcontinuouscastingparametersandstirringcurrent.Basedonthecalculationresults,themoldfluxentrapmentindexinfreesurfaceandvelocityuniformityindexwereusedtoevaluatetheflowfieldinthemold.Thetheoreticalbasisfortheoptimizationoftheflowfieldstructurewasprovided.Thestudyalsosuggestedanoptimizationmethodforelectromagneticstirringparameters.

简介：Intwin-rollstripcastingprocess,transportphenomenaoffluidinthemoltenpooldirectlyaffecttheprocessstabilityandthequalityofproducts.Inordertoelucidatethefundamentaltransportphenomenaintwin-rollcasting,acommercialsoftwarecalledProCASTwasemployedtosimulatethetransientfluidflowandlevelprofilebehaviorsduringtheearlystageoftheprocessinthisstudy.Thecoupledsetofgoverningdifferentialequationsformass,momentumandenergybalanceweresolvedwiththefiniteelementmethodandthetransientfreesurfaceproblemwastreatedwithavolumeoffluids(VOF)approach.Theeffectofdifferentdeliverysystemsconfigurationonflowpattern,levelprofileinthepoolwasstudiedandanalyzedinthispaper.Thenewwedgemetaldeliverysystemshavebeenoptimizedforthetwin-rollstripcaster.Itwasshownthatnewtypemetaldeliverysystemshadapreferableeffectontheuniformdistributionoffluidandlevelfluctuationinthepool.Thesimulationresultsalsoprovideavaluablebasisfortheoptimizationofdeliverysystemandprocessparametersduringtheinitialpouringstage.

简介：Anon-linecontrolmethodofsurfacequalityforcontinuoushot-dipgalvanizedsteelstripaftercoolingispresented,whichcombinesanalyticaldynamicstheoryofathinplatewiththefiniteelementmethod.Theinherentcharacteristicsofthenon-immersedandpartiallyimmersedstripinliquidzincwerecalculatedonthebasisoftheoreticalanalysisandnumericalsimulation,respectively.Multi-parameterfittingofthedeviationbetweenresultsusingdifferentmethodswasperformed.Tooptimizethestripexcitationfrequencyawayfromtheresonanceregion,on-linevibrationcontrolofthestripneartheairknifeunderfullproductconditionswasachievedbychangingthefieldproductionparametersbasedonthefieldtestresults.Theresultsindicatethatalthoughtheaxialvelocityhaslittleeffectontheinherentcharacteristicsofthestripcomparedwithothermanufacturingparameterssuchasthesteelspecificationsandtension,itinducesexternalexcitations,includingmovingtheaerodynamicloadandbearingvibration.Tosomedegree,thevibrationneartheairknifecanbereducedbystrengtheningthesupportstiffnessofthecontactrolls.Atotalon-linecontrolprogramofsurfacequalityforcontinuoushot-dipgalvanizedpureZnandgalvannealedsteelsheetinthecoolingsectionisproposed.