搜索
ForofficeuseonlyT1________________T2________________T3________________T4________________TeamControlNumber48649ProblemChosenAForofficeuseonlyF1________________F2________________F3________________F4________________2016MCM/ICMSummarySheetSummaryBasedontheexistingFiniteElementMethod(FEM)technique,weconsidertwomodelstoanalyzethetemperaturedistributioninthebathtub,includingwithoutandwithapersoninit.Then,webuildtwoinflowmodels,namely,thecontinuousinflowmodelandthediscontinuousinflowmodel.Atlast,weemployFuzzyComprehensiveEvaluation(FCE)toevaluatethesetwoinflowmodelsinordertofindanoptimalsolution.First,regardingthemodelwithoutapersoninthebathtub,wecalculatetheheatdissipationinthewater-to-airheatconvectionandbuildahot-watertubemodelforcalculatingtheheataddition.What’smore,tofindthetemperaturedistributioninthebathtub,wesimulatesuchmodelonANSYS,whichisalarge-scalecommonfiniteelementsoftware.Second,weconsiderthemodelwithapersoninthebathtubfromtwoaspects,namely,thepersoninthestillandthemovingstates.Specifictothemovingstateofperson,wefindthatthereexisttwowaysofdissipatingheat,includingthewater-to-airheatconvectionandthewater-to-bathtubheatconduction.Furthermore,weexploitMATLABtofindthetemperaturecurveinnaturalcoolingprocess..Third,basedontheanalysisofabovetwoconditions,weproposetosimulateonthecontinuousanddiscontinuousinflowmodelsofthehotwater.Besides,tofindanoptimalstrategy,weevaluatethesetwomodelsusingfuzzycomprehensiveevaluation(FCE),wherethevariablesincludetheamountofneededwater,thecomfortabledegreeofuser,theoperationcomplexityandtheoperativedifficultyindex.Fourth,toanalyzethesensitivityoftwomodelswithandwithoutperson,weextensivelychangethevelocityandthetemperatureofthehotinflow,theairtemperature,thesurfacearea,volumeandmaterialofthebathtub,andthevolumeofthepersonbody.Atlast,wefurtherstudythemodelforcleansingwithabubblebathadditive.Inthiscase,wevarytheconditionofthebubbletoobservethismodel’sperformance.Team#48649Page1of44Team#48649January28，2014AbstractNaturallyanon-spa-stylebathtubwithoutasecondaryheatingsystemandcirculatingjetwillgetnoticeablycoolerafterbeingfilledwithhotwater.Thewaterloseheatbothtotheairandtothebathtub.Onewanttokeepwarmbyaddingaconstanttrickleofhotwaterfromthefaucet.Tohandlefluid’soverflowing,thebathtubisdesignedinsuchawaythatwhenthetubreacheditscapacity,excesswaterescapesthroughanoverflowdrain.WebuildBathtubwithoutPersonmodel(BWOP)tosimulatethewatertemperaturedistributionwithoutpeopleinside,andBathtubwithPerson(BWP)modeltoresearchthenaturalcoolingprocessandtoproposereasonablestrategyforusertomaintainthetemperature.ThesimulationofBWOPmainlydependsonthefiniteelementmethod(FEM)usingANSYS,whilethesimulationofBWPmainlydependsonthesolvingofthethermodynamicequationusingMATLAB.Keywords:HeatConvection,HeatConduction,FiniteElementMethod,ANSYSTeam#48649Page2of44Contents1Introduction...........................................................................................................................41.1RestatementoftheProblem........................................................................................................42AssumptionsandJustifications.............................................................................................43Notations...............................................................................................................................54Modelforbathtubwithoutapersoninit(BWOPmodel)....................................................64.1Thecalculationoftheheat-transfercoefficient..........................................................................84.1.1Theheat-transfercoefficientbetweenthewatersurfaceandtheair....................................84.1.2Theheat-transfercoefficientbetweenthewaterandthewatertube....................................94.1.3Theheat-transfercoefficientbetweenthehotwaterandthecubewall.............................104.2Theheatdissipationbetweenthewatersurfaceandtheair......................................................114.3Theheatadditionbetweenthewaterandthehotwatertube....................................................114.3.1Theheatexchangebetweentheinsideandtheoutsideofthetube....................................114.3.2Theheatexchangebetweenthewaterandthewatertube.................................................124.4SimulationofBWOPmodelbasedonANSYS........................................................................145Modelforbathtubwithapersoninit(BWPmodel)..........................................................175.1Simulationofthetemperaturedistributionifthepersonisstill................................................185.2HeatdissipationinBWPmodel................................................................................................195.2.1Water-Airheatconvection.................................................................................................195.2.2Water-Bathtubheatconduction.........................................................................................205.2.3Thetotalheatdissipationinthe