Flowmaster教程04Steady State.ppt

Section4 SteadyState SteadyStateCapabilities SinglepipelinesystemsMultiplebranchingsystemsLoopedandbranchingsystems ComponentsAvailable SinglePhase AirConditioningAirsideSystemsPipes PassagesBendsValvesTransitionsPumpsControllersCOMControllersElectro MechanicalSourcesDiscreteLosses HeatExchangersLubricationSystemsJunctionsOrificesReservoirsAccumulatorsDiaphragmsWeirsMiscellaneousSupercomponentsSolids ComponentsAvailable FluidPower AirConditioningAirsideSystemsPipes PassagesReservoirs SourcesLossesAccumulatorsElectro MechanicalDCV sControlValvesCheckValvesPumpsLubricationSystems MotorsCylindersControllersCOMControllersLoadsValveDynamicsMiscellaneousSupercomponentsHeatExchangerSolids 4frictionoptionsColebrook WhiteHazen WilliamsFixedfrictionEnhancedFriction CSonly Pipes r InternalDuct FlexibleHose RotatingPassage Prismatic r Hexagonal r Rectangular Cylindrical Fluidpower Singlephase Pipes r InternalDuct FlexibleHose RotatingPassage Prismatic r Hexagonal r Rectangular Cylindrical Fluidpower Singlephase Pipes Bends 8bendsavailableinsinglephase3circularcross section5rectangularcross section2bendsavailableinfluidpowersmoothandmitrecircularcross sectionLowlosscomponents Valves4maingroups PoppetCheckValve ReliefValves r DirectionalControlValves CheckValves ControlValves FluidPower SinglePhase Valves PoppetCheckValve ReliefValves r DirectionalControlValves CheckValves ControlValves FluidPower SinglePhase Valves ControlValves SinglePhase12controlvalvesSamemathematicalmodelDifferentlossdatak valvelosscoefficientCRe correctionforlaminarflowFluidPower4controlvalvesvariablethrottlepressurereducingpressurereliefsimplereliefvalve CheckValves Singlephase4checkvalvesavailableSwing checkvalveClapper checkvalvePlug checkvalvePoppetCheckValveFluidpower4checkvalvesavailableSimplecheckvalveSpringoperatedcheckvalvePilotcheckvalvePoppetCheckValve DCV s fluidpoweronly 6available2port3port4port2position3position 3 Needtodefinechannelareavsspoolpositionpressuredropvsflowrate ReliefValves Poppetreliefvalve singlephase simulatesventingofliquidfromasystemPressurereliefvalve fluidpower remainscloseduntilcrackpressurereached Junctions Transitions 2transitionsavailableabruptgradualmodelslossassociatedwithchangesinpipediameterlossinsignificantinlongpipelines Orifices 5orificesavailabledescribedbygeometrySharp edged conical LongRadiussedSquareSharp edged standardorificeplate Pumps Pumps Single Phase Fluid Power Rotodynamic Positive Displacement Motor Reservoirs Reservoirs SinglePhase FluidPower General r ConstantHead r VariableHead r FiniteArea StorageVessel r 2 ArmedTank 3 ArmedTank ThermalExTank Accumulators Sources Usedtosetnetworkboundaryconditions6availableflowsourcepressuresourceblankendpressurevsflowsourcecontrolledflowsourcecontrolledpressure 4maingroupstabulardatacurveinputPIDCOMEnabledControllersPlus2specializedcontrollersmotortorquecontrollerpressureunloadercontroller Controllers 5maingroupsMiscellaneousControllersGeneralControllersPIDControllersValveControllersPumpControllers COMEnabledControllers Cylinders FluidPoweronly 3availableusedtotransformfluidflowintomechanicalmotioncanimposedisplacementvelocityforce Loads 3availableloadvstime tabularinput loadvstime curveinput loadvsoperationalvariable AutomotiveAirConditioning Enablessimulationofcompletethermalmanagementsystems AvailableinSinglePhaseandFluidPowerdatabases SystemPerformancecanbeanalysedwithminimaldatainputrequirements Allowsco simulationwithvehicleperformancepredictionsoftware Usesstandardgraphicaluserinterfacefacilities ACFamilyToolbar Thisapplicationintroducesanewsolver refrigerantfluids andanewfamilytoolbarthatconsistsofonlyACcomponents TheACfamily ACComponentFamily Pressure EnthalpyDiagram VapourZone LiquidZone Compression Theairconditioningcyclestartswiththecompressor ItsfunctionistocompresstherefrigerantgasIndoingthis thetemperatureandthepressureoftherefrigerantareincreasedThecompressoractslikeapump ithasanintakesideandadischargesideTheintakedrawsintherefrigerantgasfromtheevaporator compressesitandpassesitviathedischargesidetothecondenser TheCompressorThefollowingcompressorscanbemodelledinFLOWMASTER2 Piston fixedandvariabledisplacement Scroll Condensation Thecondenserisresponsibleforcoolingthehotcompressedgas Condensersaresimilartoradiators botharedesignedtoexchangeheatThecondenserissituatedatthefrontofthevehicletomaximizeheatdissipation Thehotrefrigerantentersthecondenserandpassesthroughanarrayoffinnedpipes Asitdoesso itiscooledAstherefrigerantcools itcondensesandexitsthebottomofthecondenserashighpressure sub cooledrefrigerant TheCondenser Asthehighpressure sub cooledliquidexitsthecondenser itpassesthroughanexpansiondevice AsshownthiscanbeanFOT VOVoraTXVAsthepressurizedliquidpassesthroughthedevice thepressureisreduced hencethetemperaturealsodropsTheoutputfromtheexpansiondeviceistwo phaserefrigerant Expansion ExpansionDevicesFOTTXVVOV TheevaporatorislocatedinsidetheHVACsystem whereitcoolsanddehumidifiestheairflowtothecabinItsprimaryfunctionistoremoveheatfrominsidethevehicleTherefrigerantenterstheevaporatorasalowpressureliquidandthewarmairpassingthroughtheevaporatorfinscausestherefrigeranttoboilAsitdoesso itabsorbslargeamountsofheatwhichsuperheatstherefrigeranttovapour TheEvaporator Evaporation TheThreeMainSystems Therearethreemainautomotiveairconditioningsystemsinusetoday eachdifferingbythetypeofexpansiondeviceused Accumulator FixedOrificeTube FOT System Receiver drier ThermalExpansionValve TXV System Accumulator VariableOrificeValve VOV System MechanicalComponents FLOWMASTER2playsavitalroleinthedesignofmanyhydrauliccircuitsthatinteractcloselywithmechanicalcomponents FLOWMASTER2modelsthemechanicalelementsandelectricalinputs e g aservo usingsimple directmodelsofmass spring damper friction earth forceandendstops EMcomponentsfamilytoolbar ThenewElectro Mechanicalfamily MechanicalComponents MechanicalEarth Aboundarycomponentusedtodefinethemechanicalpositionofanode MechanicalForce Enablestheforcetobedefinedasaconstant orasafunctionofdisplacementvtime MechanicalMass Fixedmassorcontrolled for3Dmechanismswhereeffectiveinertiavarieswithposition alsosetscoefficientofrestitution MechanicalComponents Friction Enablesstatic Stiction andsliding Coulomb frictionforcestomodelled Friction coulomb stiction Spacer Hasadefinedlength Itcanbeusedtotransmitforcesbetweennodes MechanicalEndStops Thecomponentmodelsapairofendstops Oneendisnormallyfixed whiletheotherisallowedtomove Itisusedtolimitthetravelofothermechanicalcomponentsinasystem MechanicalComponents Port Thiscomponentusestheorificeequationtorelatethepressureandflow Ithastwofluidconnectionsandonemechanicalconnection MechanicalSpring Enablesthestiffnesstobedefinedasaconstant orasafunctionofspringlength MechanicalDamper Enablestheviscouscoefficienttobedefinedasaconstant orasafunctionofdamperlength MechanicalComponents MechanicalPiston Usedtomodelthenetpressureforceacrossthespool theactionissimilartothe2 rodcylindercomponent MechanicalPiston 1FluidArm Thecomponentisidenticaltothe Piston component exceptthat LeakageacrossthepistonisNOTmodelledAtmosphericpressureonthedrysideofthepistonismodelled MechanicalComponents AnnularPassage modelspressuredropacrosstheannularpassage MechanicalLever Class2 IdenticaltotheClass1lever exceptthatClass2leversareusedtomodelacantileveredlinkagewherebothmechanicalconnectionslieonthesamesideofthepivotpoint MechanicalLever Class1 Canbeusedtolinkmechanicalcomponentsaboutacentralpivotpoint MechanicalComponents GenericMechanicalTemplates 1 2and3Armmechanicaltemplatesareavailable Solenoidisa force defining componentwhichtransformselectromagneticeffectintomechanicalforce AirsideSystems Enablessimulationofairsystemusingbasiccomponents AvailableinSinglePhaseandFluidPowerdatabases SystemPerformancecanbeanalysedwithminimaldatainputrequirements Usesstandardgraphicaluserinterfacefacilities AirsideSystemFamilyToolbar ThenewAirsideSystemfamily AirsideComponentFamily LubricationSystem AnewfamilyofbearingcomponenthasbeenincludedtoenableanalysisoflubricationsystemsAvailableinSinglephaseandFluidpowerdatabasesModelscanbeusedinsteadystateandtransientanalysiswithheattransferUsesstandardgraphicaluserinterfacefacilities LubricationSystemFamilyToolbar ThenewLubricationSystemfamily LubricationSystemComponentFamily MasterControllers Thenewmastercontrollerwillallowusertostorevariable curves surfaces scriptscentrallyThemastercontrollerisbasedonexistingCOMcontrolleranduserwillbeabletomodifythedata formtotheirownrequirements addtheappropriatesymbolThedifferencesbetweenthemastercontrollerandCOMcontrollerfunctionalityarethatallinformationenteredintothedata formwillbeaccessibletoallscriptsintheselectednetwork MasterControllers Selectthe COMController family Thenew MasterController templateavailableundertheCOMcontrollerfamily Thetemplatecanbecopiedandusercanmakethechangestoitasperrequirements MasterControllers Usercanspecifythedirectorylocationandfilenameoftheexternalfile Userscanspecifytheexternalfilelocationcontainingthetestdatatobeusedbycontroller TheBrowsefacilityisavailabletolocatetheexternalfile DownloadableComponents Downloadablecomponents DC areFLOWMASTERapprovedECM savailablefordownload DownloadableComponents Selectprojectwindowandclick InstallDownloadablecomponent underFilemenu Selectthelocationofdownloadablecomponentfile FMdc toinstallthecomponent AdvancedPipeDrawingSymbols Thenewsymboleditorfunctionalityallowsuserstheproductionofenhancedsymbolsforpipes ThisnewfunctionalitywillallowuserstocreateFLOWMASTERdiagramstomatchthatofotherpipingdocuments CustomToolTips CustomToolTipswillallowuserstoassigntheirowntextstringstofluid controllerconnectionTooltips Editthesymbolandrightclickthefluid controllerconnectionandselect ChangeFluid ControllerToolTip andenterthenewtextstringthethedialogbox Section5 SteadyStateExamples SinglePhaseSteadyStateExample1 TypicalResults Ex1 SinglePhaseSteadyStateExample2 TypicalResults Ex2 FluidPowerSteadyStateExample3 TypicalResults Ex3 FluidPowerSteadyStateExample4 TypicalResults Ex4 Section6 Transient FLOWMASTERTransientCapabilities Pumpstart upandtripControlvalvedynamicsCheckvalvedynamicsReliefvalvedynamicsBehaviorofsurgeprotectionequipmentInfluenceofcontrolactionsonpressuresurge Causesofseverepressuresurge RapidchangesinvalvepositionsStartingorstoppingofpumpsandturbinesControlvalvehuntingThermalchangesinthesystemVibrationofsystemcomponentssuchasreciprocatingmachinery Suppressionoffluidtransients StrongerpipesRe routingModifyingexistingcomponentsInstallingsurgesuppressiondevices WavePropagation EstimationofthemaximumtransientpressurechangeJoukowskyEquation TimingofEvents Rapid eventUseelasticpipemodel Slow eventUseelasticmodelforfasteventsAboverigidmodelmaybeappropriate Veryslow eventConsiderusingtherigidpipemodel SpeedofPropagationofPressureWaves Wavespeedequation Pipe 4pipemodelsRigidCompliantElasticVariablewavespeedImpactontimestep RigidPipeModel MassoscillationbehaviorShortlengthsofpipeinlongsystems Slow events ElasticPipeModel UsesMethodofCharacteristicsrequiresdistance timegridforallelasticpipes S criteriaSmustbewithinofanintegergreaterthan3 ElasticPipeModel Ifthe S criteriadoesn tfitforeachpipemakesmalladjustmentstopipelengthsmodeltheendsectionofapipeasRIGIDMakeadjustmentstothewavespeed Valves ControlvalvescanvaryvalveopeningwithtimeCheckvalvesNeedadditionaldatae g characteristicoperatingtimePossibleimpactonstabilityofsolutionGasAdmissionandReleaseValveModelsgasflowbetweenanexternalreservoirandcavitywithinsystem Pumps RotodynamicpumpscanbecontrolledbylogicstatesLogicstate 1 pumprunningatconstantspeedLogicstate0 motoroff pumptripped Logicstate1 controlledtorqueorspeed Controllers TabularandcurveAllowa position vstimerelationshipPIDcontrollersCanapplyactionthatisoneormoreof inverselyproportionaltomeasuredsignaltimeintegralofmeasuredsignalderivativeofmeasuredsignal 5maingroupsMiscellaneousControllersGeneralControllersPIDControllersValveControllersPumpControllers COMEnabledControllers S CriterionExercise S CriterionExercise Downstreampipelength 675mfrictionoption1 roughness 0 025mmdiameter 0 15melasticoption wavespeed 1250m sBallvalve FP DCV diameter 0 15mValvetabularcontrolleruntil1s valveopenafter2s valveclosedDownstreampressuresourcepressure 10bar Upstreampressuresourcepressure 11barUpstreampipelength 1000