Öchsner, g. murch, a. shokuhfar j. delgado abstract book · a. Öchsner, g. murch, a. shokuhfar...

DSL2009/RomeITALYABSTRACTBOOK 1

.Editedby:

A.chsner,G.Murch,A.ShokuhfarandJ.Delgado

AABBSSTTRRAACCTT BBOOOOKK

DDSSLL 22000099 RROOMMEE -- IITTAALLYY 2426JUNE,2009

www.dsl2009rome.com

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PREFACE

It isourgreatpleasure towelcomeyou to the5TH INTERNATIONALCONFERENCEONDIFFUSION INSOLIDS AND LIQUIDS: MASS TRANSFER, HEAT TRANSFER, MICROSTRUCTURE AND PROPERTIES,NANODIFFUSIONANDNANOSTRUCTUREDMATERIALS,DSL2009,intheancientRomeItaly,from2426June,2009.DSL2009aimedatattractingabalancedportionofdelegates fromacademia, industryand researchinstitutions and laboratories involved with research and development work. In doing so, theconference provides a binding platform for academics and industrialists to network together,exchange ideas, provide new information and give new insights into overcoming the currentchallenges facing the academics and the industrialists relating to Mass Transfer, Heat Transfer,MicrostructureandProperties,NanodiffusionandNanostructuredMaterials.

Iwould like to thank theOrganisingCommitteemembersandmembersof theLocalCommitte fortheirhelp in contributing to the successfulorganisationof thismeeting and special thanks toProf.OronzioMancaforhissupporttohelpparticipantstogetVISAsfromtheItalianEmbassies.

Iwouldliketothankthecolleagues,organisersoftheSPECIALSESSIONS,Thankyou!

AspecialthankstoProfessorGraemeMurch,ProfessorAliShokuhfarandProfessorJooDelgado,cochairsofDSL2009,fortheexcellentwork,significantinputsandsupporttothisconference.

Concernshavebeenexpressedaboutthe influenza(H1N1FLU),traveltoRomeetc...However, inthemiddleofallquestionswithoutanswersdelegatesdidthewaytillhereandIwould likepersonallytothankalldelegatesforthedecision inattendingDSL2009hopeyouwillfindthemeetingveryusefulforyourwork,businessandausefulforumforobtainingnewknowledge.

Havefunlearningandmeetingnewpeople!

Behelthyandkeepyourselfhelthy!

Seeyouagainin2010,inParis!

ProfessorAndreaschsnerDSLCONFERENCESChairman


ORGANISINGCOMMITTEE

SCIENTIFICCOMMITTEE

Prof.Dr.Ing.A.chsner(chair)UniversityofMalaysia,MalaysiaProf.Dr.G.Murch(cochair)TheUniversityofNewcastle,AustraliaProf.Dr.A.Shokuhfar(cochair)K.N.ToosiUniversityofTechnology,IranProf.Dr.J.Delgado(cochair)UniversityofPorto,Portugal

LOCALCOMMITTEEProf.Dr.OronzioManca(HeadofLocalCommittee)SecondaUniversita'degliStudidiNapoli,ItalyDr.GiovanniMazzolaiUniversityofPerugia,ItalyDr.Ing.AssuntaAndreozziUniversita'degliStudidiNapoliFedericoII,ItalyProf.Dr.AntonioBarlettaUniversita'diBologna,ItalyProf.Dr.NicolaBiancoUniversita'degliStudidiNapoliFedericoII,ItalyDr.BernardoBuonomoSecondaUniversita'degliStudidiNapoli,ItalyDr.Ing.GianPieroCelataENEA,ItalyDr.MicheleCelliUniversita'diBologna,ItalyProf.Dr.NicolaMassarottiUniversita'degliStudidiNapoliParthenope,ItalyProf.Dr.SergioNardiniSecondaUniversita'degliStudidiNapoli,ItalyProf.Ing.VincenzoNasoUniversita'degliStudidiNapoliFedericoII,ItalyDr.Ing.EugeniaRossidiSchioUniversita'diBologna,ItalyProf.RosarioCantelliUniversitDegliStudidiRoma"LaSapienza",Italy

Prof.I.BelovaTheUniversityofNewcastle,Australia

Prof.R.BennacerUniversitdeCergyPontoise,FranceProf.B.BoksteinMoscowInstituteofSteelandAlloys,RussiaProf.I.E.CamposSilvaIPNSEPIESIME,MexicoProf.M.DanielewskiAGHUniversityofScienceandTechnology,PolandProf.A.N.DmitrievInstituteofMetallurgyoftheUralBranchofRussianAcademyofSciences,RussiaProf.A.FishmanUralDepartmentofRussianAcademyofSciences,RussiaProf.A.A.KodentsovEindhovenUniversityTechnology,TheNetherlandsProf.ChanGyuLeeChangwonNationalUniversity,KoreaProf.W.O.F.LengauerViennaUniversityofTechnology,AustriaProf.G.MishurisRzeszowUniversityofTechnology,PolandProf.H.NakajimaOsakaUniversity,Japan

Prof.Y.SohnUniversityofCentralFlorida,USAProf.B.B.StraumalInstituteofSolidStatePhysics,RussiaProf.M.UematsuKeioUniversity,JapanDr.G.RomaC.E.Saclay,FranceProf.OdilaFlorencioUFSCAR,BrazilDr.H.FujikawaAirWaterIncorporated.,JapanProf.CarlosRobertoGrandiniUNESP/Bauru,BrazilL.S.ShvindlermanUniversityofAachen,GermanyProf.DezsoL.BekeUniversityofDebrecen,HungaryProf.PaulHeitjansLeibnizUniversityHannoverGermanyDr.BernardAUFRAYCINaMCNRSFranceProf.M.ZinigradArielUniversityCenterofSamaria,IsraelProf.V.TeixeiraUniversityofMinho,Portugal

Prof.P.PizaniUniversidadeFederaldeSoCarlosUFSC,BrazilProf.R.V.RamnathMassachusettsInstituteofTechnologyMIT,USAProf.J.P.RinoUniversidadeFederaldeSoCarlos,BrazilProf.M.A.J.SomersTechnicalUniversityofDenmark,DenmarkDr.PhilippeMaugisArcelorResearchSA,FranceProf.F.CoutelierisUniversityofIoannina,GreeceProf.R.F.MoreiraMartnezUniversidadedeSantiagodeCompostela,SpainProf.T.V.MorosukMaritimeUniversityofSzczecin,PolandProf.M.E.R.ShanahanUniversityofBordeaux,FranceProf.I.A.WierszyllowskietalForming

Prof.I.MalicoUniversidadedevoraPortugalDrGailR.DuursmaUniversityofEdinburghKingsBuildings,UKDr.EusebioSolrzanoUniversityofValladolid,SpainProf.M.ELGanaouiUniversityofLimoges/CNRS,FranceDr.CorneliaBreitkopfTechnischeUniversittBergakademieFreibergGermany

Dr.DevendraGuptaIBMThomasJ.WatsonResearchCenter,USAProf.HuseyinCimenogluIstanbulTechnicalUniversity,TurkeyProf.ToshitadaShimozakiKyushuInstituteofTechnology,JapanProf.RafalKozubskiJagellonianUniversity,PolandProf.HelmutMehrerUniversittMnster,GermanyProf.R.ShahbazianYassarMichiganTechnologicalUniversity,USAProf.G.J.CreusUniversidadeFederalRioGrandeSulUFRGS,BrazilDr.W.EibZikaLeime,GermanyDr.RodolfoArielPrezComisinNacionaldeEnergaAtmica(CNEA),ArgentinaDr.J.CermakInstituteofPhysicsofMaterialsoftheAcademyofSciencesoftheCzechRepublicProf.YvanHoubaertGhentUniversity,BelgiumProf.M.J.S.DeLemosITA,BrazilProf.V.PopovInstituteofMetalPhysics,RussianAcademyofSciences,RussiaProf.S.SeetharamanRoyalInstituteofTechnology,SwedenProf.K.SefianeTheUniversityofEdinburgh,UK


6th 6THINTERNATIONALCONFERENCEONDIFFUSIONINSOLIDSANDLIQUIDS:MASSTRANSFER,HEATTRANSFER,MICROSTRUCTUREANDPROPERTIES,

NANODIFFUSIONANDNANOSTRUCTUREDMATERIALSwww.dsl2010-paris.com


ADVANCEDCOURSEIN:

FOCUS1:Structural,FunctionalandSuperhard NanoStructuredMaterials:

scientificFundamentalsandIndustrialapplicationsLECTURER:ProfessorDr.Dr.h.c.StanVeprek

TechnicalUniversityMunich,Germany

NOTE:thiscourseislimitedtoasmallnumberofparticipants,reserveyourplacesoon!

FOCUS2:AdvancedMaterialsCharacterizationTechniques:surfaceandstructuralanalysis

LECTURER:ProfessorDr.SamZhangNanyang TechnologicalUniversity,Singapore

NANOSTRUCTURED MATERIALSMANUFACTURING, CHARACTERISATION AND APPLICATIONS

WHO SHOULD ATTEND?Peoples from academia and industry working in the area ofnanostructured materials are encouraged to attend thiscourse to deepen and widen their knowledge. In addition, thecourse is designed for those who would like to start to work inthe challenging area of nanotechnology...................................

REGISTRATIONFEE:980EUR*(*)Registrationincludes: 3fulldayscoursewithtwowell knownLectures, PrintedCourseMaterials, CourseCertificate, 2refreshmentsdaily, LunchatTheRitzCarltonHotel(daily/3days)

CONTACT:IRONIX CONTINUINGEDUCATIONEmail:[email protected]: 0075537727(IRONIXMalaysia)Contactperson:Ms.MeireGomeswww.ironixconferences.com

2123September,2009THERITZCARLTONHOTELKualaLumpurMALAYSIA


....

TTAABBLLEEOOFFCCOONNTTEENNTTSS::

PLENARYLECTURES8

Experiments,theoryandmodellingofheattransportandfluidflow 12

Masstransportandrelatedphenomenainmetalsandalloys 46

diffusioninamorphousmaterials 70

Masstransportandrelatedphenomenainnonmetallicmaterials 73

Theoryandmodellingofmasstransportandrelatedphenomena 100

IndustrialApplicationsofMassTransportandRelatedPhenomena 134

ReactiveDiffusion 177

MassTransportandRelatedPhenomenainNaturalProductsandPharmaceuticals 156

SPECIASESSION:HeatandMassTransferinPorousMedia 179

SPECIALSESSION:Grainboundariesandinterfaces:structure,thermodynamicsanddiffusionproperties 219

SPECIALSESSION:HeatTransferinCellularandCompositeMaterials 230

SPECIALSESSION:DiffusioninIntermetallics 239

CharacterizationandPropertiesofHardCoatings 258

SPECIALSESSION:MicrostructuralControlThroughDiffusionProcesses 278

SPECIALSESSION:FrontiersofNanostructuredMaterials 298

SPECIALSESSIONON:MicrostructuralAnalysisandPropertiesofMaterials 361


PlenaryLectures


DSL2009HonoraryChairmanVIPDSL008Prof.B.BoksteinMoscowInstituteofSteelandAlloys,RUSSIA

OpeningLecture:DiffusionatShortCircuits.

StateoftheArtB.S.Bokstein

Evidenceforsolidstatediffusion(thesecondhalfof19thcentury).Thefirstmeasurementsofsolidstatediffusion(W.RobertsAustin(1896)1922).Thefirsttracerexperimentstodeterminethesolidstatediffusion(G.vonHevesy,19131923).Thefirstevidenceofaccelerateddiffusioninpolycrystallinematerials(19241935).Autoradiographicstudiesofgrainboundarydiffusion(50thof20thcentury).Thefirstquantitativeexperimentalandtheoreticalstudiesoftheshortcircuitingdiffusion(beginningfrom1949,D.TurnbullandR.HoffmanGeneralElectricResearchLab.):radiotracerserialsectioningmethod,Fishersmodel(1951)forgrainboundarydiffusion,exactsolutionsanddevelopmentsofFishersmodel(19541963).Theprogressintheexperimentalmethodsfordeterminationofgrainboundarydiffusiondataandresultsofmeasurementsfordifferentmetallicsystems(uptodate).ThemeasurementsofgrainboundarydiffusionparametersinBandCregimes.Themeasurementsofdiffusivitiesalongmigratinggrainboundaries,dislocationpipes,lowanglegrainboundaries,phaseboundaries,triplejunctionsofgrains.Diffusioninthinfilms.Effectofgradientenergyandstress.Grainboundarydiffusionandgrainboundarysegregation.Nonlinearsegregationeffects.Structuraleffectsofgrainboundarydiffusion.Diffusioninbicrystals.Diffusioninnanocrystals.Grainboundarywettingandgrooving.ComputersimulationofgrainboundarydiffusionMechanismsofgrainboundarydiffusionConclusion:whereandwhyarewegoing?


VIPDSL075Prof.M.A.DayanandaPurdueUniversity,WestLafayette,Indiana47907,USA

SelectedAnalysesandObservationsinMulticomponentDiffusion

Selected isothermal diffusion studies in ternary and quaternary systems are reviewed in order topresentanalyticalandexperimentalapproachesadoptedforthedeterminationof interdiffusionfluxesof components, interdiffusion coefficients, diffusional interactions among components, and internalconsistencyintheexperimentaldata.Several interesting phenomena and observations including uphill diffusion, zeroflux planes and fluxreversals, flux reversals at interfaces,nonplanar interfaces, demixing of phases, uncommon diffusionpaths, and diffusion structure evolution are illustrated with selected single phase and multiphasediffusioncouplesinCubasedandFebasedternarysystems.Themainchallengesinvolvedintheexperimentaldeterminationofinterdiffusiondatafrom


VIPDSL065Prof.G.P.CelataENEA,EnergyDepartment,InstituteofThermalFluid,Dynamics,Rome,Italy

SingleandTwoPhaseFlowHeatTransferinMicropipes

Partly because of the technological challenge, partly because of stark necessity, there has been anincreasingmovementtowardsaminiaturizationofappliances inthe lastdecade. Inalltechnical fieldssolutions are sought that encumber as little as possiblewithout compromising on performance: inmedicaldiagnostics,environmentalsampleanalysis,militarydefence,consumerelectronics,biomedicalappliances,chemicalreactorsandheatmanagementaconstantresearchforquickerresponsetimesandportabledeviceshasdriventhefieldofmicrotechnologytoimpressivelevels.Inmanyapplicationsithasbeenfoundthatmanysmallactivecomponentsaremoreproductivethanfewlargeones,whichisalsoinkeepingwiththegrowingtrendtowardsmodulardesign.Properunderstandingofmicroscaletransportphenomenaisthereforefundamentalforthedesignerofmicrofluidicdevices.For this reason,many studieshavebeen conducted toanalyse thebehaviourofconvectiveflowthroughmicrochannels,bothinsinglephaseandintwophaseflow.Afirstglanceoftheliterature, especially for singlephase flow, leads to the conclusion that up to nowwe have had anagglomerationofdisparateconclusions.Inmanycasestheexperimentaldatainmicrochannelsdisagreewith theconventional theoryandempiricalcorrelations,but theyalsoappear tobe inconsistentwithoneanother.Thepresentlectureisanattempttocriticallyanalysetheavailableresultsforliquidsinglephase and flow boiling heat transfer, trying to provide some sort of base note in themelisma ofpublisheddata.


Experiments,TheoryandModellingofHeatTransportandFluidFlow


DSL224Dr.ImenGaiedInstitutPrparatoireAuxEtudesdIngnieurdeNabeulIPEINMerazka8000Nabeul,Tunisia

InvestigationofopticalandthermoelectricalpropertiesofSnSb2S4thinlayerusingthePhotothermalDeflectionTechnique

ImenGaied1,AbdelazizGassoumi2,MounirKanzari2andNoureddineYacoubi11InstitutPrparatoireAuxEtudesdIngnieurdeNabeulIPEINMerazka8000NabeulTunisie

2ENITBP37,lebelvdre1002TunisTunisia

SulfosaltSnSb2S4filmshavebeendeposedonglasssubstratesbythermalevaporationandsubsequentlythermallyannealedinvacuumattemperaturesfrom100to200C.Belowatransitiontemperatureof140C.,thefilmsarehighlyresistivewithadominantamorphouscomponent,howeverabove this temperature, the samplesexhibitp+type semiconductorbehaviorwithadominantcrystallinecomponent.Inthisworkwehavestudiedthethermalandopticalpropertiesofthesefilmsusingthephotothermaldeflectiontechnique.Thethermalpropertiesaredeterminedbycomparingtheexperimentalamplitudeand phase curves variations versus square rootmodulation frequency of the photo thermal signal to the correspondingtheoreticalones.Thebesttheoreticalfittingcurvesareobtainedforwelldefinedvaluesofthermalconductivityandthermaldiffusivity.Theopticalabsorptionspectrum isobtainedbycomparingtheexperimentalnormalizedamplitudeofthephotothermal signal curves variations versus wavelength to the corresponding theoretical curves variations versus opticalabsorption coefficient.We have determined the energy gap by using the Tock law. From a measure of the samplesresistance,one candeduce theelectrical resistivity so theelectricalconductivitywhichmaybecorrelated to the thermalconductivity.VIPDSL042Prof.J.P.RinoDepartamentodeFsica,UniversidadeFederaldeSoCarlosViaWashingtonLuizkm235,13569080,SoCarlos,SPBrazil

EquilibriumandnonequilibriumMolecularDynamicscalculationsofheatconductioninInSb

GiovanodeOliveiraCardozoandJosPedroRinoDepartamentodeFsica,UniversidadeFederaldeSoCarlosViaWashingtonLuizkm235,13569080,SoCarlos,SPBrazil

Thermal conductivityofmaterials atnanometrical scales is aprime subjectofmaterial sciences and engineering,mainlybecauseof the largeapplicationofnanoscaledmaterials inmicroeletronics,where it isalwaysnecessary tocombinehighperformanceandlowcosts.Inmoleculardynamics thereare twomainways tocalculate thermalconductivitycoefficients.The first is theequilibriumone,where the Fourier transformation of the heat current autocorrelation function, at zero frequencies limit, gives thethermal coefficient value (GreenKubo formula). The second method is the direct one, or non equilibrium, where atemperaturegradientisimposedtothesystem,generatingaheatcurrentwhichisrelatedtothegradientandtothethermalconductivity coefficient via Fourier law.Here it is shown the results for equilibrium and non equilibrium calculations of thermal conductivity coefficient in bulksystemsofInSbusinganeffectivetwoandthreebodyinteratomicpotentialwhichhasbeenverytransferable.Forequilibriumcalculationsacubicsystemwith5unitcellsside,andconsequently1000particles,andperiodicboundaryconditions inalldirections,wasused.Theaverageheatcurrentautocorrelation functionwascalculated fora0.03ns timeinterval,whichwas longenough to stabilize the system,over1000 independent runs.Thisprocedurewas repeated for5temperatures,300K,400K,500K,900Kand1000K,andtheresultswerecomparedtoexperimentaldata.


Fornonequilibriumcalculationssystemswith5x5xNunitcells,andperiodicboundaryconditions,withfourdifferentvaluesofN,wereused:50(resultingin10000particles),200(with40000particles),400(with80000particles)and640(with128000particles).Thetemperaturegradientwas imposedbyaddingandsubtractinganamountofenergyrespectively inahotandacold reservoir,placed in regionsof thesystemseparatedbyadistanceL. In thestationary regime the temperaturegradient between reservoirs is linear and its slope and themean value of are related to the thermal conductivitycoefficientbytheFourierLaw. Inthe limitof infinite lengthsystem,byextrapolation,thisthermalcoefficienttendstothecorrectvalue for thematerialunder investigation.The temperatures inhotandcold reservoirswere fixed respectivelyat250K and 350K for all systems. Simulations weremade for at least 106 time steps, to reach stationary regime. Oncestationaryregimewasreached,anotherrunof106timesteps,or1,5ns,wasproceededtoobtainthecoefficientvalue.In these calculations in both cases, equilibrium and non equilibrium, the obtained results were comparable to theexperimentaldata. For equilibrium calculations at300K the coefficient valuewas about10Wm1K1,which is in goodaccordancewith non equilibrium calculation,whose obtained valuewas about 16Wm1 K1. Both cases are in goodagreementwithexperimentaldataof15Wm1K1reportedbyMagomedovandBilalov.11Y.B.MagomedovandA.R.Bilalov,Semiconductors35,499501(2001).DSL528Prof.IvanaSalopekubriUniversityofZagreb,FacultyofTextileTechnology,PrilazbarunaFilipovica28a,10000Zagreb,Croatia

TheSimulationofHeatandVapourTransferTroughFibrousMaterialsI.Salopekubri,Z.Skenderi

UniversityofZagreb,FacultyofTextileTechnology,PrilazbarunaFilipovica28a,10000Zagreb,Croatia

The heat andwater vapour transmitting properties of fibrousmaterials are important factors that affect the clothing'scomfortaswellasthequalityofspecial functionalclothingthat isworn inextremeenvironmentalconditions. Inordertomaintainthetotalbalancewithinthebody,theroleoffibrousmaterialsistocontributetothemaintenanceofthefollowingequation:MW=R+C+E+L+K+S,where:M=totalrateofenergyproductiondeterminedfromtherateofoxygenconsumption;W=rateatwhichexternalworkisbeingperformed;R=radiation;C=convection;E=evaporation;L=warmingandwettingofairwhichisinhaledandthenexhaled;K=conductionandS=rateofstorageofheatinthebody.Thepaperintroducesadvancedsystemforthesimulationofphysiologicalprocessesthatappearnexttothehumanskin.Itsuseenables themeasurementofheatand vapour transfer trough fibrous structures,aswellasdeterminationof vapourpermeability and permeability index. The experiments reported here refer to themeasurement of a number of fibrousmaterialsused for thenexttoskinwear. For themeasurementhavebeenproducedmaterials thatdiffer either in theirstructureorrawmaterialinordertoobservetheinfluencesofdifferentparameterstothetransferproperties.Thetransfertroughfibrousmaterialsismainlyaffectedbyitsstructurethatcomprisesofarepeatunitswithcellulargeometrycontainingairpores,yarnsthatformbasicstructureandintersectionpointsoftwoormoreyarns.Therefore,thestructureofmaterialsisalsoinvestigatedanddescribedbymeansoffabricmoduli.Dynamicsofheatandvapourtransferisobservedthroughtheexperimentallyobtaineddataandthe influenceofanumberofstructuralparameters isdiscussed.Thestatisticalmethodsareusedtoqualifytheeffectsofinvestigatedvariablesontheheatandvapourresistance.DSL042Prof.PavolKotialFacultyofMetallurgyandMaterialsEngineering,DepartmentofMaterialsEngineering,17.listopadu15/2172,70833OstravaPoruba,CzechRepublic


ThermoMechanicalMaterialAnalysisPavolKotial1,IvanRuiak2,ZdenkJonta1,MiroslavTvrd1

1FacultyofMetallurgyandMaterialsEngineering,DepartmentofMaterialsEngineering,17.listopadu15/2172,70833OstravaPoruba,CzechRepublic

2InstituteofMaterialandTechnologicalResearch,FacultyofIndustrialTechnologies,UniversityofAlexanderDubekinTrenn,I.Krasku491/30,02001Pchov,SlovakRepublic

[email protected],[email protected],[email protected],[email protected]

The experimental system for complex thermomechanicalmaterial analysis (CTMA) is presented in this paper. Systemprovidesmeasurementusual for tensile testaswellasheatgeneration in theprocessofdeformation.Wemeasured thecoolingcurveofthesampleafter itsdeformation.Onthebasisofexponentialmodelofcoolingbodywith respecttoBiotnumber(Bi)valueitispossibletocalculateheatcapacitycp[J/kgK],thermaldiffusivity[m2/s]andthermalconductivity[W/m.K]..Themethodhadbeen testedon the varietyofmaterialsand the resultswere compared to those in chartsorobtainedby reference independentexperiments.Weobtained verygoodagreementofallobtainedexperimental resultswiththoseofcomparativeones.DSL260Dr.RitaAguilarOsorioInstitutoPolitcnicoNacionalSeccindeEstudiosdePosgradoeInvestigacinUnidadProfesionalAdolfoLpezMateos.Edificio5,3er.PisoCol.Lindavista,C.P.07738,Mexico,D.F.

NumericalSimulationofHeatLossbetweenaPartitionPlateandtheWalloftheHeadofaPlasticHeatExchanger

R.AguilarOsorio1andK.Cliffle21InstitutoPolitcnicoNacionalSeccindeEstudiosdePosgradoeInvestigacin

UnidadProfesionalAdolfoLpezMateos.Edificio5,3er.PisoCol.Lindavista,C.P.07738,Mexico,D.F.Emailaddress:[email protected]

2DepartmentofMechanicalandChemicalProcessesEngineering,SheffieldUniversity.MappinStreet,SheffieldS13JD,UK

Forthisresearchwasconsideredthattheheatexchangerwasaffectedbyleakageintheheadacrossthepartitionplateandthewall between the tube passes. Leakagewas aproblem in theplastic shell and tubeheat exchanger,because itwasdifficulttosealthepartitionplatetotheheadoftheexchanger.Thematerialusedformanufacturingtheheatexchangerwaspolyvinylidene fluoride,PVDF. Inorder topredict theamountof flow leaking throughtheclearancesofthetubepassesanumerical simulation was carried out using a computational Fluids Dynamics CFD Fluent Software. The results of thissimulationwereusedtoinvestigateiftheflowleakageaffectedtheheattransferperformanceoftheexchangersufficientlytorequireimprovementofthedesign.Toobtainthepercentageoftheheatlossacrossthetubepassesdifferentclearancesizesbetweenthepartitionplateandthewalloftheheadoftheexchangerwereanalyzed,for4tubepasses.Forthesmallerclearance sizeof0.2mm theheat transfer coefficientwas reducedup to15%.These results suggest that the flowmassbypassingtheheadbetweentubepassesaffecttheresultsoftheheattransfercoefficientandconfirmtheobservedfromtheexperimentalresults,thatitsperformancewasaffectedbyleakagebetweentubepasses.Thisresearchservedasanextensionofthepreliminaryplasticheatexchangerdesign.Theleakageproblemwasovercome,inacurrentdesign, fixing thepartitionplateon thewallof theheadandsealingverycarefully thecomponentsof theheatexchanger.DSL044Dr.HayderA.AbdulBariFacultyofChemicalandNaturalResourcesEngineering,UniversityMalaysiaPahang,Malaysia


GlycolicAcidEthoxylate4TertButylphenylEtherasDragReducingAgentinAqueousMediaFlow

HayderA.AbdulBari1,EmmaSuali1andZulkafliHassan11FacultyofChemicalandNaturalResourcesEngineering,UniversityMalaysiaPahang,Malaysia.

2FacultyofPharmacy,InternationalIslamicUniversityMalaysia

Glycolicacidethoxylate4tertbutylphenyletherwasusedas investigatedanionicsurfactants inthisexperimentalwork.Abuiltuprigwithratioofpipelengthtodiameter(L/D)isequalto59wasusedtoachievethepurposeofthisworkwhichtoinvestigatesthedragreductioninturbulentflowwithdifferentflowratesandconcentrationofadditive.Inapresentstudy,theconcentrations (ppm)ofadditivewereanalyzedstartingfrom200,300,400,500and600,respectively.Theflowrates(Re)ofsolutionwerefrom11235,22470,33705,44940,56175,67410and78645,respectively.Itwasfoundthatglycolicacidethoxylate4tertbutylphenylethercapabletoreducedraglessthan10%.Thehighestdragreductionwasachievedis8%in600ppmofsolutionforturbulentflowwithRewithinrange44940to56175.Theresultsofexperimentalworkshowsthattheseanionicsurfactantsperformasapoordragreducingagentduetoitsdragreductionvaluesincreasesonly1to3%eventhough the concentrationof solutionwas added about 100ppm. This is occurredprobablybecauseof the formationofmicelleinsolutionisnotinafullythreadlikeforms.Keywords:Dragreduction;criticalmicellesconcentration;turbulentflow;AnionicsurfactantsDSL276Dr.R.LeticiaCorralBustamanteInstitutoTecnolgicodeCiudadCuauhtmoc,Cuauhtmoc,Chihuahua,Av.TecnolgicoS/N,Z.P.31500,Mxico

HeatTransferinBlackHolesR.L.CorralBustamante*,D.Senz,N.I.Arana

InstitutoTecnolgicodeCiudadCuauhtmoc,Cuauhtmoc,Chihuahua,Av.TecnolgicoS/N,Z.P.31500,Mxico.*Correspondingauthor:Email:[email protected]

Phone&Fax:+526255811707Ext.114.

Duringmodelingofgiganticmasses incontinuumspacetime,someofthesolutionstotherelativisticequationsofEinsteingiverisetosingularitieswhichallowpredictheattransferthatitisoriginatedinblackholesofhugeintensityofgravitationalfield[1].Ablackholeisathermodynamicsystemwhosevolumeofcontrolisboundedbytheeventhorizon;theoccurrenceofheattransferinitsinterioranditsboundarycanbeexpressedbythedegreeofdisorderorentropy,whichisindicativethatblackhole showsemissions. Thereforeablackhole isnot soblack,due to the radiationproduced. Theelectromagneticemissionofparticlesoftheblackholetothesurroundingscanleadtoitsextinctionorcollapse.In this paper ametric is postulated starting from a entropy balance of a black hole as a thermodynamic systemwhichcontainstheenergytransportacrosstheborder,duetomasstransfer,heattransferandwork,andthegenerationofentropy[2,3].The relativisticequationobtained is treatedasaquantumequation (quantumgravity). Of thecalculationsmade intermsofgeneralrelativityandthermodynamicsprinciplesforhugemasses,ispresentedevidenceofaBigBangprobable:Aprincipleoftheuniversethroughthesingularityfound,anditisclarifiedanexpandinguniverseduetodegreeofdisorder.[1]A.Ashtekar,V.Taveras,M.Varadarajan,Phys.Rev.Lett.,100,211302(2008).[2]J.L.Tane,J.ofTheoretics,2,3(2000).[3]J.L.Tane,J.ofTheoretics,3,4(2001).DSL150Dr.YogeshJayantBhaleraoMaharashtraAcademyofEngineering,Alandi(D),Pune,(MS),India


ThermalModelingofWetGrindingProcessbyusingDesignofExperimentsY.J.Bhalerao1,S.R.Kajale2

1MaharashtraAcademyofEngineering,Alandi(D),Pune,(MS),India.2SGGSInstituteofEngineeringandTechnology,Nanded,(MS),India.

Grindingingeneralisaverycomplexmaterialremovaloperationinvolvingcuttingaswellasploughingandrubbingbetweentheabrasivegrainsand theworkmaterial.Thehigh temperaturesaremajor sourceof thermaldamageon themachinedsurface. In thepreviouswork a simplemovingheat sourcemodelhasbeendeveloped to estimatemaximumworkpiecesurfaceandaverageworkpiecesurfacetemperatureduringsurfacegrindingprocessindrycondition.ThemodelisvalidatedbyusingDesignofExperiments(DoE)techniques.Inthispaperthepreviousmodelisfurtherdevelopedtofindmaximumandaverageworkpiecesurfacetemperatureduringsurfacegrindingprocessinwetcondition.Experimentationisdoneonferrousaswellasnonferrousmaterials.Althoughwidelyusedinindustry,grindingremainsperhapstheleastunderstoodofallmachiningprocesses.Howitisappliedis often depends upon the experience of the operator, rather than scientific knowledge.Despite the extensive researchdeterminingdesirableoperatingparametersofgrindingprocessesinanindustrialsettingoftenreliesonoperatorsskillsandtrial and error approach. This is due to the difficulty of transferring the laboratory based research results and availablemodelsto industrialpracticewheregrindingsetupsandparametersaredifferentandalsothere is lackofthesymmetricaltoolto integratevariousheterogeneousmodelsand information.Thisresearchpaperattemptstohighlightandtrytogivesolutionforthesame.[1]Malkin,S.andGuo,C.GrindingTechnology:TheoryandapplicationsofmachiningwithabrasivesSecondEdition,IndustrialPress,NewYork,2008.[2]Malkin,S.andGuo,C.ThermalAnalysisofgrindingAnnalsofCIRPManufacturingTechnology,KeynotePaper,Volume56/2(2007),pp.760782.DSL519Dr.SunilKr.JainUniversityCollegeofEngineering,RajasthanTechnicalUniversity,Kota324022,India

CorrectionFactorfortheEstimationofEffectiveThermalConductivityofHighPorosityTwoPhaseSystems

1SunilKr.Jain,2RamvirSingh1UniversityCollegeofEngineering,RajasthanTechnicalUniversity,Kota324022,India2HeatTransferLab,DepartmentofPhysics,UniversityofRajasthan,Jaipur302004,India

The transport of heat across a porous system with either open or closed cells is dominatedbyconduction.Becauseofhighporosity,thesesystemshave largeapplications in lightweightstructures,vibrationcontrol,energymanagement etc. Polyurethane and ceramic foams play an important role in thermal insulation applications likepackingof food,chemicalcatalyticreactorandsolarenergyapplications.Ontheotherhandmetallic foams likealuminumandtitaniumfoamsfinduseinerectinglightstructureswherestrengthandtoughnessisimportant.Thesemetalfoamshavebetterutilization in cooling towers,heat shielding inaircraft exhaust,highpower electronicdevicesetc. For a varietyofapplicationsofthesematerials,studyoftheirthermophysicalpropertiesisessential.The effective thermal conductivityof such systems ismainlydependentonporosity, thermal conductivityof constituentphases and morphology of cells. Single theoretical expression cannot provide the estimation for effective thermalconductivityforallkindofsuchsystemsandgeometries,whichexistinrealphysicalsystems.AtheoreticalexpressionforETCofhighporositytwophasesystemspresentedhereisbasedonequivalentthermalresistorsformedoutofphasesintheformofparallelslabsandresistormodelapproachhasbeenused.Weproposeanduseamodeltocalculateeffectivethermalconductivitybytaking intoaccounttherandomizationofseriesandparallelarrangementsofheat flux lines.To incorporate the interactionbetweenphases,acorrection factorhasbeenintroducedwhichhasbeendevelopedbysimulationofdataavailable inthe literature.This factor iscorrelated intermsofweightageof thermal conductivitieswith fractional volumesof the constituents.Theexpression for correction factorhas


beentakenout intermsofthermalconductivitiesofsolidandfluidphaseforpropercorrelationwiththe involvedphases.Latereffectivethermalconductivityiscalculatedbyincorporatingthecorrectionfactorforvarioussamplesofmetallicfoamsandtwophasehighlyporoussystem.Theresultssoobtainedareinresemblancewiththeavailablevaluesofeffectivethermalconductivityforthesehighporositysystems.Keywords:Correctionfactor,Effectivethermalconductivity,Porosity,Seriesandparallelresistors.DSL085Dr.K.J.SinghDepartmentofPhysics,S.G.N.KhalsaP.G.College,SriGanganagar335001INDIA

ComputationalAspectsofEffectiveHeatStorageCoefficientofMultiphaseSystems

K.J.Singh1andRamvirSingh21DepartmentofPhysics,S.G.N.KhalsaCollege,SriGanganagar(Raj.)335001.

2HeatTransferLaboratory,DepartmentofPhysics,UniversityofRajasthan,Jaipur302004,India.

Atheoreticalmodel,topredicteffectiveheatstoragecoefficient(HSC)fromthevaluesofHSCsoftheconstituentphases and their volume fractions for real twophase systems ispresented, assuming aneffective continuousmedium (ECM), it isextendedtothreephasemoistporousmaterials.Particlesareassumedtobeellipsoidal inshapeandarranged inthreedimensionalcubicarray.Thearrangementhasbeendivided intounitcells,eachofwhichcontainsanellipsoid.TheHSCsof theunitcellhasbeendeterminedbyapplying resistormodel.Totakeaccountofthenonlinear flowofheat flux lines inrealsystems, incorporatinganempiricalcorrection factor inplaceofphysicalporositymodifiesanexpressionforHSC.AneffortismadetocorrelateitintermsoftheratioofHSCsoftheconstituentsandthephysicalporosity.Totestthevalidityofthederivedexpression,theHSCofsomebuildingmaterials saturatedwith different liquids has been determined. A good agreement has been foundbetweentheexperimentalandthepredictedvaluesreportedintheliterature.Keywords:Effectiveheatstoragecoefficient;effectivecontinuousmedium;porousmedia;correctionfactorDSL210Mr.YogeshSonavaneOttovonGuerickeUniversity,TheInstituteofFluidDynamicsandThermodynamicsUniversityplatz2,Postbox4120,Magdeburg,39106Germany

NumericalModelingoftheRotaryKilnsintheIndustrialProcesses

byUsingANSYS(FiniteElementMethod)E.Specht1,Y.S.Sonavane2

1OttovonGuerickeUniversity,TheInstituteofFluidDynamicsandThermodynamicsUniversityplatz2,Postbox4120,Magdeburg,39106Germany

2OttovonGuerickeUniversity,TheInstituteofFluidDynamicsandThermodynamicsUniversityplatz2,Postbox4120,


Magdeburg,39106Germany

Heattransfermechanism iscomplicated incaseofrotarykilnas it includesconduction,convectionandradiationatasametime.Theheattransfermodelhas tobesolvednumericallybecauseofthetwodimensionalproblemswhichconsiderthethermal heat conduction in radial and circumferentialdirection. In order to predict and improve the evolution and thedistributionoftemperaturesintherotaryfurnace,anumericalanalysisisundertakenusingANSYS11finiteelementpackage.Thestandardelementtypeplane55fortwodimensionalthermalsolidsisused.Anumericalsimulationincludestemperaturedistributionontheinternalsurfaceofthewallinordertoimprovetheunderstandingoftheheattransferprocessacrossit.Analysis ofthetemperaturedistributionacrossthecircumferentialandradialdirection,temperaturefluctuationcausesonthe boundary conditionswere studied thoroughly. All results clearly indicates the temperature distribution for differentangular velocity andwithdifferentheat transfer coefficientsunderdifferent fillingdegree.Penetrationdepthhavebeeneasilyobservedinontheradialsideofthewall.Penetrationdepthisaround12mmwhereallcurvemeettogether.Onlythisthicknesstakespartinheattransferprocess.Temperatureatthesolidsideisdecreasecontinuouslyandatthegassideitfirstincrease because of regenerative heat phenomenon. Experimental results are qualitativelymatcheswith theNumericalresults.Temperaturefluctuationsincreasewithincreaseinrotationalspeedhasbeenobserved.DSL252Prof.MnicaOliveiraDepartamentodeEngenhariaMecnica,UniversidadedeAveiro,CampusUniversitriodeSantiago,3810193Aveiro,Portugal

ThermodynamicandTransportPropertiesofCNTWaterBasedNanofluids

J.Ponmozhi1,F.A.M.M.Gonalves2,A.G.M.Ferreira2,I.M.A.Fonseca2,S.Kanagaraj3andM.S.A.Oliveira11DepartamentodeEngenhariaMecnica,UniversidadedeAveiro,CampusUniversitriodeSantiago,3810193Aveiro,

Portugal2DepartamentodeEngenhariaQumica,UniversidadedeCoimbra,PloII,RuaSlvioLima,3030790Coimbra,Portugal

3MechanicalEngineeringDepartment,IITKanpur,Assam,India

Carbonnanotubes(CNTs)perhapsthemostenticingclassofnanomaterialsareaddedinsmallvolumefractionstoenhancethermalpropertiesoffluidswhenprocess intensificationanddeviceminiaturizationarerequired.Thisworkreportsontheresults obtained when measuring viscosity, surface tension, density and thermal conductivity of homogenous carbonnanofluids. The influence of CNTs volume concentration on the nanofluid thermo physical properties is studied andmeasurementsareundertakenatdifferenttemperatures,rangingfrom10Cto60C.ThenanofluidswerepreparedbyaddingdifferentvolumeconcentrationsoftreatedCNTstowater.ThelatterweresonicatedforonehourandthecolloidalstabilitywasmonitoredwithaUVspectrophotometer,theabsorbanceofthenanofluidwasobservedat253nm, theaverageconcentrationofCNTwasmaintainedat9.35mg/levenafter200hours,over97%whencomparedwiththe initialconcentration.Asthevolumeconcentrationincreases,theviscosityrises,forthesameshearrateandtemperature[1].The viscositywasmeasured using a controlled stress rheometer .Themeasurementswere performed in the shear raterangingfrom0to1200sec1.ThethermalconductivitywasmeasuredwithaKD2ProthermalpropertytesterfromDecagondevices and the results show that thermal conductivity riseswith CNTs concentration.A further steeper rise in thermalconductivity, forhigh volumepercentagesandhigher temperatures, canbeobserved,being the results inaccordance tothosereportedby[2,3].Therefore,itcanbeobservedathermalconductivityriseupto45%forCNTsconcentrationof5%vol,whencomparedwithitsvalueforthebasefluidwater,between10Cand30C,anda70%increasefor40and50Cupto1%vol.Beingresultsobtained,incloseagreementwiththoseobtainedbyDingetal[3].[1]G.H.Ko,K.Heo,K.Lee,D.S.Kim,C.Kim,Y.sohn,M.Choi,IntJHeatandMassTransfer,50,.4749(1990).[2]S.U.S.Choi,Z.G.Zhang,W.Yu,F.E.Lockwood,E.A.Grulke,ApplPhyLetts,79,2252(2001).[3]Y.Ding,H.Alias,D.Wen,R.A.Williams,IntJHeatandMassTransfer,49,240(2006).


DSL302Prof.JoseAlbertoReisParisePontifciaUniversidadeCatlicadoRiodeJaneiro,RiodeJaneiro,RJ,22453900,Brazil

ANumericalStudyontheApplicationofNanofluidsinEvaporatorsJ.C.V.Loaiza,Y.R.Benito,F.C.Pruzaesky,J.A.R.Parise

PontifciaUniversidadeCatlicadoRiodeJaneiro,RiodeJaneiro,RJ,22453900,Brazil

Thepresentpaperispartofabroaderprojectaimingatthecharacterizationofheatpumpsemployingnanofluids.Theadditionofnanoparticlestoliquidsformsthenanofluids,whichhaveshowntoenhancesignificantlytheheattransfer characteristics of the solution. In thiswork, amathematicalmodel is presented describing a straightdoublepipehorizontalevaporator,with refrigerant flowing through the annular section and theheattransferfluidflowingthroughtheinnertube.Amultizonemodelisemployed.Theevaporatorisdividedintotwozones:boilingtwophaseandsuperheatedvapor.Fourdifferentnanofluidsarestudied:H2O/Cu,H2O/CuO,H2O/Al2O3andH2O/TiO2.Models forthedeterminationofthethermodynamicandtransportproperties,aswellasoftheheattransferandpressuredroopmechanisms,wereemployed[1,2,3]todescribethenanofluids.Energybalancesandheattransferequationswereappliedtoeachzoneoftheheatexchangerresultinginasystemofnonlinearequations.Resultshaveshownthattheuseofnanofluidsinevaporatorsassecondaryfluids,reducedtherequiredrefrigerantvolume,thusreducingitsenvironmentalimpact.[1]S.P.JangandS.Choi,RoleofBrownianMotionintheEnhancedThermalConductivityofNanofluids,AppliedPhysicsLetters,84,pp43164319,(2004).[2]V.Velagapudi,R.K.Konijeti,C.S.K.Aduru,EmpiricalCorrelationstoPredictThermophysicalandHeatTransferCharacteristicsofNanofluids,ThermalScience,12,2,pp2737,(2008).[3]W.S.Heris,N.M.Esfahany,Gh.S.Etemad,ExperimentalInvestigationofConvectiveHeatTransferofAl2O3/waterNanofluidinCircularTube,InternationalJournalofHeatandFluidFlow,28,pp203210,(2007).DSL347Dr.Kalaiselvam.SDepartmentofMechanicalEngineering,AnnaUniversityChennai,India600025

ApplicationofAnodized/SprayPyrolysedNanoporousStructureinConvectiveHeatTransferAppliances

Kalaiselvam.S*,Gugan.M.S,Kuraloviyan.E,Meganathan.R,NiruthiyaPriyan.A,Swaminathan.M.RDepartmentofMechanicalEngineering,AnnaUniversityChennai,India600025

This paper investigates the augmentation of convective heat transfer by administering nanoporous layers formed byelectrochemicalanodizationandspraypyrolysis.Thecontrolparametersofthefabricationprocessarestudiedtoprepareananoporouslayerwithmaximumporosityforheattransferapplications.Thenanoporouslayersformedareperusedwiththehelpof scanningelectronmicroscopeandatomic forcemicroscope.Nanoporous structures formedon themetal surfaceenhancethecapillaryactionwhich leadstoconsiderable incrementinconvectiveheattransfer.Thenanostructuresformedonthesurfaceaidinachievingtheturbulenceexpeditiously.Nanoporouslayersincrementtheheattransferofpolishedbaremetalswithwaviness 0.2 m to amaximum of 133.3%.Outcome of experiments illustrate an impressive heat transferaugmentation of 58.3 % in etched metals of surface roughness 3 m. Nanopores of size 75 to 95 nm formed byelectrochemicalanodization,andporesofsize4050nmformedbyspraypyrolysisamelioratetheheattransferby130%.This imposesagreater impact indesignofcompactheatexchangers inchemicalandpowerplants.Anoveltechnologyforeffectiveutilizationofthermalenergyhasbeencontrivedandithasitspotentialapplicationsinbothactiveandpassiveheattransferaugmentationmethods.Influenceofporesizeandflowvelocityonconvectiveheattransferisalsoinvestigatedwiththehelpofcompiledexperimentationresults.


Keywords:Nanoporoussurface,ElectrochemicalAnodization,SprayPyrolysis,Convectiveheattransfer*Correspondingauthor.Tel.:+914422203262.Emailaddresses:[email protected](Kalaiselvam.S),[email protected](Gugan.M.S),[email protected](Kuraloviyan.E),[email protected](Meganathan.R),[email protected](NiruthiyaPriyan.A),[email protected](Swaminathan.M.R)DSL420Prof.AmedeoAmoresanoMechanicalandEnergeticDepartment,NaplesUniversityFedericoIIViaClaudio2180125Italy

IdentificationoftheThermalDiffusivityofAutomotiveCompoundsTyresUsingaLASERSourceandIRCamera

A.Cristophe1,A.Amoresano2,D.Giordano2,M.Russo21NationalResearchCouncil,NaplesViaClaudio2180125IT

2MechanicalandEnergeticDepartment,NaplesUniversityFedericoIIViaClaudio2180125IT

Theoperatingtemperatureofthetireshasalargeinfluenceontheirperformanceintermsofhandlingandwear.Withregardtohandling,thisbasicallydependsonthetireroadinteractionor,precisely,ontheforcesthatthetireisabletoreceivefromtheroadandtopasstothevehicle.Theseinteractionsdependonthetemperature,accordingtoalawthatisfirstincreasingandthendecreasingwiththetemperature.Soexists,atleastintheory,anoptimaltemperature,orratherarangeofoptimaltemperaturesthatmaximizethevaluesoftheforcesexchangedbytheway,fixedanyothercondition.Thepaperdescribesanewmethodologytomeasurethethermaldiffusivityoftheautomotivetirescompound.Thismethodologyusesa laserasthermalsourcetoheatthesurfaceoftheinsulatedspecimenstakenfromthetire.Theknowledgeofthethermalpowerofthe laserbeam,whichheatsasurfaceof thesample,and the lawsof temporal temperaturemeasuredduring the testbythermocoupleandIRcamera,allowsidentifyingthediffusivityofthecompound.DSL438Mr.S.V.S.S.N.V.G.K.MurthyDepartmentofMathematics&Statistics,IndianInstituteofTechnologyKanpur,Kanpur208016,India

DarcyNaturalConvectioninaNonNewtonianFluidSaturatedSquareporousEnclosurewithaWavyverticalWall

S.V.S.S.N.V.G.KrishnaMurthy,B.V.RatishKumar21,2DepartmentofMathematics&Statistics,

IndianInstituteofTechnologyKanpur,Kanpur208016,India.

In this paper the Darcy natural convection process induced by an isothermal verticalwavywall in a porous enclosuresaturatedwith powerlaw typeNonNewtonian fluid is considered. The coupled nonlinear partial differential equationsmodelingsuchafreeconvectionprocessarethensolvedbyFiniteelementmethod.Numericalresultsillustratingtheeffectsof the governing parameters such as Rayleigh number (Ra), powerlaw index (n), number ofwaves per unit length (N),amplitudeofthewavycurvemodelingthewall(a),phaseofthewavycurve(),ontheconvectionprocessarepresented.Theflowandtemperaturefieldsareanalyzedthroughstreamlines,isothermsandLocal/Cumulativeheatfluxplots.[1]B.V.RathishKumar,P.V.S.N.Murthy,P.Singh,IJNMFI,28(4),633,(1998)[2]M.A.Hossain,D.A.SRees,ActaMechanica.136,133(1999).


[2]G.B.Kim,J.M.Hyun,NumericalheatTransfer,PartA:Applications,45,569(2004).[3]B.V.R.Kumar,Shalini,MohitNigam,VivekSangwan,andS.S.N.G.K.Murthy(toappear)inJournalofMechanicsinMedicineandBiology,(2009).[4]ChingYangCheng,InternationalCommunicationsinHeatandMassTransfer(2009).DSL511Dr.MaximilianSergueiMesquitaDepartamentodeEngenhariaeCienciasExatasDeceUniversidadeFederaldoEspiritoSantoUFES,SaoMateus,ES,29933415,Brazil

MixedConvectioninaVentedEnclosureFilledwithSquareRodsandwithanIsothermalVerticalSurface

M.S.Mesquita1andM.J.S.deLemos21DepartamentodeEngenhariaeCienciasExatasDece

UniversidadeFederaldoEspiritoSantoUFES,SaoMateus,ES,29933415,Brazil2DepartamentodeEnergiaIEME

InstitutoTecnologicodeAeronautica,SaoJosedosCampos,SP,12228900,Brazil

Thisworkpresentsanumericalstudy formixedconvection flow inanenclosurewithan isothermalwallfilledwithsquarerods.Forcedconvection flowconditionsare imposedbyprovidingan inletat thebottomofthe isothermalsurface,andaventatthetop,facingtheinlet.Buoyancyisgeneratedbecauseofthedifferenceintemperaturesbetweenthewallandthethroughstream.Comparisonsareobtainedbynumericallysolvingaconjugateheattransferproblemthatconsidersboththesolidandthefluidspace.Governingequationsaresolvedusingthefinitevolumemethodandthealgebraicequationset isrelaxedwiththeSIPprocedure.TheaverageNusseltnumberatthehotwall,obtainedfromthecavitywithsquareobstaclesandforseveralDarcynumbers,arecomparedwiththosecalculatedwithcleanmedium.DSL340Mr.WonjaeChoiGraduateSchool,Dept.ofRefrigeration&AirconditioningEngineering,PukyongNationalUniversity,Busan,607739,Korea

PerformanceCharacteristicsofCapacityControlonIndustrialWaterCoolerUsingPMV

W.J.Choi1,H.W.Kim1,S.M.Baek1,H.J.Kang2,H.S.Lee3,J.I.Yoon31GraduateSchool,Dept.ofRefrigeration&AirconditioningEngineering,

PukyongNationalUniversity,Busan,608739,Korea2DuksanCotran,Daegu,702030,Korea

3CollegeofEngineering,SchoolofMechanicalEngineering,PukyongNationalUniversity,Busan,608739,Korea

Recently,technicaltrendformachinetoolsisfocusedonenhancingofspeedandaccuracy.Forhighspeedandhighaccuracy,athermaldeformationmustminimizeinmachinetools.Tominimizethethermalinfluence,accuracymachinetoolsneedtobeadoptedacoolingsystemwithhighprecision.Inthisstudy,wesuggestahighaccuracywatercoolingsystemusingPMV(PulseModulationValve)control.Inthissystem,weuseacompressorwhichisabletobedriveninconditionofunloadingtoimprovetheefficiencyofPMVcontrol.Andavaporrefrigerantfromthesuctionsideofthecompressorisinjectedbackintothecompressorsuctionsideagainusingasolenoidvalve.ThePMVcontrolcanbeusedbythismethod.Also,bycomparingwiththeexistingONOFFcontrolmethodonidenticaloperatingconditions,weevaluatedtheefficiencyandreliabilityofthenewmethod. Thismethod showed the shorter reaction time than that of the existingmethod. Also, the efficiency and


performanceimprovedbylowercompressorworkusingthevaporinjectionwithoutcompressorstop.Thisresultwillbeusedforabasisdataofcomparativeexperimentwithinvertercontrolandmanufactureofhighaccuracywatercoolingsystem.Acknowledgments:ThisresearchwassupportedbyDuksanCotranandSmallandMediumBusinessAdministration(SMBA)oftheKoreangovernment.[1]M.Yaqub,S.M.Zubair,J.R.Khan,J.Energy,25,543(2000)[2]C.P.Tso,Y.W.Wong,P.G.Jolly,S.M.Ng,J.InternationalJournalofRefrigeration.,24,543(2004).[3]C.M.Kim,Y.J.Hwang,Y.H.RyuandK.S.Cho,Conf.SAREK(2001).DSL354Mrs.NaaBeronskInstituteofMaterialsandMachineMechanics,SlovakAcademyofSciences,Raianska75,83102Bratislava3,SlovakRepublic

ThermalConductivityandThermalExpansionofCopperMatrixCompositesReinforced

withhighmodulusCfibresN.Beronsk,P.tefnik,K.Idinsk,

InstituteofMaterialsandMachineMechanics,SlovakAcademyofSciences,Raianska75,83102Bratislava3,SlovakRepublic

Thornel K1100 high modulus carbon fibres combine large thermal conductivity (~ 900 1000Wm1K1)withvery lowcoefficientofthermalexpansion(1.5x106K1).Copperbasedcompositesreinforcedwiththesefibresmayyieldquiteuniquecombinationofphysicalpropertieswiththermalconductivityhigherthanthatofpurecopperandcoefficientofthermalexpansionaslowas~1x106K1.HoweverduetonowettingintheCuCbinarysystemseriousproblemswith thecompositepreparationneed tobeovercomewhenapureCumatrix isused.Moreover,unidirectionalfibre alignment results in a large anisotropy of composite properties. Finally due to lack of chemical affinity there is noreaction interfacialbondingandthestructuralstabilityofthecomposite is inquestion.Gaspressure infiltrationtechniquehasbeenused topreparecopperbasedcompositematerialunidirectionally reinforcedwith~54vol.%ofThornelK1100carbonfibres.Asreceivedcompositeexhibitedhomogeneousdistributionoffibreswithsomeporesandvoids inthe interfibre locations. Thermal diffusivitywasmeasured in longitudinal and transversal direction by the flashmethod and themeasured datawere fitted to amodelwhich takes into account the finite flash duration. The thermal conductivitywascalculated from the diffusivity measurements using calculated values of density and specific heat. Thermal expansionmeasurementswereperformedin5subsequentcyclesattheheating/coolingrateof0.05C/suptothetemperatureof600C in longitudinaland transversaldirections.The structural stabilityof the compositewas confirmed.Actually, in spiteofweakbonding,therewerenosignsofanycompositedisintegration.Thethermaldiffusivitywasnotaffectedbytheappliedthermalcycling.DSL357Mr.HosseinDavarzaniInstitutdeMcaniquedesFluidesdeToulouse(IMFT)AlleduPr.CamilleSoula,31400Toulouse,FRANCE

TortuosityEffectonThermalDiffusionCoefficientinPorousMediaH.Davarzani,M.Marcoux,M.Quintard

InstitutdeMcaniquedesFluidesdeToulouse(IMFT)AlleduPr.CamilleSoula,31400Toulouse,FRANCE


ThermaldiffusionorSoreteffect,whichisthemassfluxcausedbyatemperaturegradientappliedtofluidmixture,hasbeentaken into account in many porous media applications, particularly in petroleum engineering and geophysics. In theliterature,theeffectivemacroscalediffusioncoefficientsarenowwellestablished[1],whileuncertaintyremainsconcerningtherelationshipbetweentheeffectivethermodiffusioncoefficientandmicroscaleparameters(suchasporescalegeometry)[2].OurpreviousstudyontheoreticalmodelofeffectivethermaldiffusioncoefficientforapurediffusionregimeconfirmedthatthetortuosityfactoractsinthesamewayonbothFickdiffusioncoefficientandonthermodiffusioncoefficient[3].In this study, new experimental results obtainedwith a two bulb apparatus are presented. The diffusion and thermaldiffusion of a HeliumNitrogen system through cylindrical samples filed with glass spheres of different diameter aremeasuredattheatmosphericpressure.ConcentrationsaredeterminedbyanalysingthegasmixturecompositioninthebulbswithaKatharometerdevice.Theresultsare ingoodagreementwiththeoreticalresultsandemphasizetheporosityofthemediuminfluenceonbothdiffusionandthermaldiffusionprocess.[1]M.Quintard,L.Bletzaker,D.Chenu,andS.Whitaker,Chem.Eng.Sc.,61,2643(2006).[2]P.Costeseque,T.Pollak,J.K.Platten,andM.Marcoux,EuropeanPhys.J.E,Softmatter,15(3),249(2004). [3]H.Davarzani,J.Chastanet,M.MarcouxandM.Quintard,LactureNoteoftheIMT8,Vol.3,p.181,(ForschungszentrumjlichGmbH,Bonn,Germany,2008).DSL195Prof.KhairulAlamDepartmentofMechanicalEngineering,OhioUniversity,Athens,OH45701USA

DevelopmentofThermalModelsUsingAccurate3DGeometryofCarbonFoamKhairulAlamandMihneaAnghelescu

DepartmentofMechanicalEngineering,OhioUniversity,Athens,OH45701USA

One of the potential applications of carbon foam is its use in thermalmanagement, including convection heat transferthroughitspores.However,becauseofthemanufacturingprocess,themicrostructureofcarbonfoamisquitecomplex,andthestudyoftherelationshipbetweenitsmicrostructureandbulkpropertiesisadifficultproblem.Severalauthorshaveusedidealizedgeometries toderive the thermalpropertiesbasedon themicrostructure.However, theanalyticalmodelsoftenproduceresultsthatarehigherbyafactoroftwoormorecomparedtoexperimentalresults.Theobjectiveofthisstudyistouse an accurate three dimensional solidmodel of carbon foammicrostructure to calculate bulk thermal properties. Aspecializedtoolforthecharacterizationof3dimensionalstructuresusingautomatedserialsectioningandlightmicroscopyisused to produces a solidmodel for analysis by the finite elementmethod (FEM). The analysis of this true geometrydemonstratesthattheidealizedmodelstendtooverestimatethethermalconductivityofthecarbonfoam.DSL279Mr.AdrianCirciumaruFacultyofMechanics,DunreadeJosUniversity,Galai,800008,Romnia

ThermalconductivityoffabricreinforcedfilledepoxymatrixcompositesG.Andrei,I.G.Brsan,A.Crciumaru,N.Diaconu

FacultyofMechanics,DunreadeJosUniversity,Galai,800008,Romnia

TailoringtheelectromagneticpropertiesofPMC isoneof themost importantaims incomposites researches.Oneofthemost common solutions is to fill the compositesmatrixwith variouspowders [1]. In this case thedimensions of fillersparticlesareimportantwhiletheydeterminethedimensionsofinterfacechangingnotonlytheelectromagneticpropertiesbut also themechanical and thermal properties.When a PMC is designed the properties of reinforcement, fillers andpolymerhavetobetakenintoaccount[2].Thecurrentresearchisfocusedinshowingtheinfluenceoffilledpolymericlayersoverthepropertiesoffabricreinforcedcomposite.Bothcarbonfiberfabricandkevlarandcarbonfiberfabricwereusedas


reinforcements.Thesymmetryoffilledpolymeric layerswaschanged inordertopointoutthe influenceoffillersoverthecompositespropertiesandtoinvestigatethepossibilityofmodifyingtheelectromagneticpropertiesformthesurfacetothemidplan of the sample. The multicomponent composites could represent the cheapest solution when controllablepropertiesarerequired.Inordertoestablishtherightamountoffilleritisnecessarynotonlytoanalyzetheelectromagneticandmechanicalpropertiesbutalsothethermalproperties[3,4].ThermalconductivityofpseudolaminatecompositeswasinvestigatedusingtheDSCtechnology.Also,thermalconductivityofsinglereinforcement layer immersed infilledepoxywasevaluatedforvariousconcentrationsoffillers inordertostartadatabasewithinformationregardingtherelationshipbetweenthethermalconductivityofalayerandthermalconductivityoflayeredmaterial.[1]S.M.Abbas,M.Chandra,A.Verma,R.Chatterjee,T.C.Goel,Composites:PartA,37,2148(2006).[2]J.Shen,W.Huang,L.Wu,Y.Hu,M.Ye,Composites:PartA,38,1331(2007).[3]Y.Xu,G.Ray,B.AbdelMagid,Composites:PartA,37,114(2006).[4]M.Mulle,R.Zitoune,F.Collombet,P.Olivier,Y.H.Grunevald,Composites:PartA,38,1414(2007).DSL332Dr.M.JavadMaghrebiMechanicalEngineeringFaculty,ShahroodUniversityofTechnogy,Shahrood,Iran

AHighOrderTimeAdvancementSchemeforPredictionofSolidificationProcesses

A.AbbasNejad*1,M.J.Maghrebi1andH.BasiratTabrizi21MechanicalEngineeringFaculty,ShahroodUniversityofTechnogy,Shahrood,Iran2MechanicalEngineeringFaculty,AmirkabirUniversityofTechnogy,Tehran,Iran

Transient heat transfer problems involving melting and solidification have an important role in many engineeringapplications. Ingeneral terms, thereare twonumericalapproachesused in solving solidificationproblems: fixedgridanddeforminggrid.Enthalpymethodshavebeenapopularmeansofnumericallysolvingphasechangeproblems.Amajorreasonforthis isthatanenthalpyformulationremovestheneedtosatisfyconditionsonthemovingboundary,whichmeansthatfixedgrid solutioncanbeused.Thenumerical solutionofenthalpymethod is investigatedby severalauthors.VollerandCross [1]usedcontrolvolumetechnique forthismethod.Voller [2]applied implicitenthalpymethod formetalsandalloysolidification.CrowleyandOckendon[3]andWilsonetal.[4]simulatedalloysolidificationusingenthalpymethod.RecentlyKrabbenhoftetal.[5]solvedphasechangeproblemsusinganimplicitmixedenthalpytemperaturemethod.Thefirstorderforwardschemeandcentralspacefinitedifferencewasusedfortimeadvancementandspatialderivativemodeling.InthispaperweappliedathirdordercompactRungeKuttamethodfortimeadvancementwithsecondordercentralspacefinitedifferenceforspacederivativestoincreasetheaccuracyofnumericalsolution.Theresultsarecomparedwithanalyticalandsemianalyticalsolutionintheliteratureforbothpureandalloymaterials.[1]Voller,V.R.andCross,M."Accuratesolutionsofmovingboundaryproblemsusingtheenthalpymethod",int.J.HeatMassTransfer,Vol.24,pp.545556,1981.[2]VollerV.R.,"Animplicitenthalpysolutionforphasechangeproblems:withapplicationtoabinaryalloysolidification",Appl.Math.Modelling,Vol.11,pp.110116,1987.[3]Crowley,A.B.andOckendon,J.R.,"Onthenumericalsolutionofanalloysolidificationproblem",Int.J.HeatMassTransfer,Vol.22,pp.941947,1979.[4]Wilson,D.G.,Solomon,A.D.andAlexiades,V.,"Amodelofbinaryalloysolidification",Int.J.Numer.Meth.Engin.,Vol.20,pp.10671084.,1984.[5]KrabbenhoftK.,DamkildeL.andNazemM.,"Animplicitmixedenthalpytemperaturemethodforphasechangeproblems",HeatMassTransfer,Vol.43,pp.233241,2007.


DSL115Mr.MohammadRezaMobinipouyaDepartmentofChemistry,FirouzabadIslamicAzadUniversity,Firouzabad,Iran

TurbulentfreeconvectionutilizingsevenbinarygasmixturesMohammadRezaMobinipouya1,andMohammadMehdiPapari2,

AntonioCampo3,MohsenAzari41DepartmentofChemistry,FirouzabadIslamicAzadUniversity,Firouzabad,Iran

email:[email protected],ShirazUniversityofTechnology,71555313,Shiraz,Iran

email:[email protected],Fax:9871173545233DepartmentofMechanicalEngineering,UniversityofVermont,Burlington,Vermont,USA

4DepartmentofChemistry,FirouzabadIslamicAzadUniversity,Firouzabad,IranKeywords:turbulentboundarylayers,freeconvection,binarygasmixture

For turbulent free convection utilizing binary gasmixtures instead of air, the impact that the four participating thermophysicalproperties mix, mix,Cp,mix,and mixexertson thealliedconvectivecoefficienthmix, /Bconjoined to severalbody configurationsmay be summarized as follows. Among the seven heliumbased binary gasmixtures at a low filmtemperatureof300KlinkedtoEq.(1),HeCF4gasmixtureturnsouttobethebetterbinarygasmixture.Itisfirmlybelievedthat the theoretical resultsof this technical present papermaybeuseful for the efficaciousdesignof cooling processesinvolvingturbulentfreeconvection.Whencontrastedagainstairorhelium,thedegreesoffreedomthattheHebasedbinarygasmixturesbring forwardmay lead to substantial reductions in the sizeand/orweightof the engineeringdevices.Thepresentpaper investigatesapromisingavenueforthe intensificationofturbulentfreeconvection invariousconfigurationsusingadequatebinarygasmixtures inwhich(He) istheprimarygascomponentandcarbondioxide(CO2),methane(CH4),nitrogen (N2), oxygen (O2), xenon (Xe), tetrafluoromethane (CF4) and sulfurhexafluoride (SF6), are the secondary gascomponents.Usingmicro scales of turbulence, Arpaci and Larsen[3] demonstrated that the convective coefficient h forturbulentfreeconvectioningasesowingPrandtlnumberPr~1respondstotheproportionality

51

2

243

=

Pm C

Bh


References[1]G.D.Raithby,K.G.T.Hollands,Chapter6,in:W.M.Rohsenow,etal.,(Eds.),HandbookofHeatTransferFundamentals,McGrawHill,NewYork,1985.[2]T.Misumi,K.Kitamura,JSMEInt.J.36(1993)143.[3]V.Arpaci,P.S.Larsen,ConvectionHeatTransfer,PrenticeHall,EnglewoodCliff,NJ,1984[4]A.E.Bergles,Chapter10,in:W.M.Rohsenow,etal.,(Eds.),HandbookofHeatTransfer,McGrawHill,NewYork,1973DSL288Mr.ZamoumMohammedFacultdesSciences,Dpartementdephysique,UniversitdeBoumerds,35000,Tunisia

EnergyDissipationwithoutFrictionofGasBubbleM.Zamoum1andM.Kessal2

1FacultdesSciences,Dpartementdephysique,UniversitdeBoumerds,35000.2FacultdesHydrocarburesetdelaChimie,UniversitdeBoumerds,35000.

Email:m_zamoum2000@yahoo.frAgasbubbleinaliquidmediumismodeledbytheRayleighPlessetequation[1],coupledwithenergyconservationandheattransferbyconvectionrelation[2]

( )=

+

PP

g

dxdR

23

dxRdR 0

2

2

2

, 0dt

dUqdtdVP =++ and ( )= TTHAq

ThenumericalresolutionofthissystemisperformedbyafourthorderRungeKuttamethod.Theobtainedresultsshowtheconvectionheattransfercoefficienteffectonthebubbleradius(Figure1andFigure2)NomenclatureRbubbleradius.Vvolumeofbubble.Aareaofbubble.TtemperatureTambienttemperature.Hconvectiveheattransfercoefficientqheattransferrate.UinternalthermalenergyPpressionofbubblePambientpressiong0newtonsconstantdensity.Bibliographies[1]LaCavitation,McaniquesetPhysiqueetAspectsIndustriels.PressesUniversitairedeGrenoble[2]Introductiontounsteadythermofluidmechanics,FrederikJ.Moody;AWILLYINTERSCIENCE1990


0 2 4 6 8 10 12 14 16 18 20-0.8

-0.6

-0.4

-0.2

0

0.2

0.4

0.6

0.8

1

t

R

H=100

Figure1.Gasbubbleoscillationforcase(H=100W/m2K)

0 2 4 6 8 10 12 14 16 18 20-0.5

0

0.5

1

t

R

H=0

Figure2.Gasbubbleoscillationforadiabaticcase(H=0)DSL439Dr.AnilKumarShrotriyaDepartmentofPhysicsSethMotilal(P.G.)CollegeJHUNJHUNU333001Rajasthan,India

EstimationofHeatStorageCoefficientofMultiphaseSystemsUsingaNewDevelopedResistorModel

A.K.ShrotriyaDepartmentofPhysics,SethMotilal(P.G.)College,JHUNJHUNU333001

Rajasthan,India

Thethermalpropertiesof interestarethethermalconductivity,thethermaldiffusivityandspecificheatc.Sincethesethreequantitiesare interrelated, (=/c,where isdensity).Knowledgeofanytwodeterminesthethird.Besidesthethreethermophysicalcoefficientsneededtodescribethethermalstatusofasubstance,theheatstoragecoefficient(HSC)


isanadditionalusefulparametertodescribeitsthermalbehaviour.Althoughitsvalueisrelatedtothethreeconstants=cinmanycasesitbehavesasanindependentcharacteristicofthesample.ThevariousfactorswhichgenerallyaffecttheHSCofmaterialsare:

chemicalcomposition physicaltexture temperature pressure heatflow

InadditiontoprovidingreliableHSCdata, it isdesirabletofindacorrelation,empiricalorotherwisebetweentheHSCandothereasilymeasuredparameterssuchasporosity,formationfactor,etc.Inthispaper,theHSCofdifferenttypeofsoilmaterialslikedrydunesand,marblestonepowder,surkhisand,drycement,loamysoil,limestonepowderandashhavebeenstudiedexperimentallyaswellastheoreticallyfortwophasesystems.Thedetermination of HSC of three phase systems has also been done using liquidairsolid phase systems by addingwatercontent and tertiary amyl alcohol as a liquid in twophase systems. In thismodel porosity and particle size plays animportantrole.TheplaneheatsourcemethodwasusedforthemeasurementofHSCofthesematerials.Theexperimentaldataandestimatedvaluesaresocloseandverifythesuccessofmodelforthesetypesofmultiphasesystems.Themainconsiderationsthatmotivatedtoundertakethisstudyare

Thesematerialsarenaturallyabundantandarecommonlyusedinbuildingconstruction. Theknowledgeofthermophysicalpropertiesofsandandashhasimportanceinagriculture. TheHSCparameterhasnotbeenmuchinvestigatedsofar. IftheHSCofthesematerialsatlowinterstitialairpressureiscomparabletotheHSCofsilicaandglasswool,thesecheapermaterialsmaypossiblyreplacethecostlyandhazardousinsulationinhugeinstallation.

Fieldsolarpondsaresurroundedwithsoilandconcrete.Theheatstorageefficiencyofpowergenerationofthesepondsdependsupontheheatlossesfromthepondthroughthesematerials.

Itisalsoimportantfromenergystoragepointofview,tohavetheknowledgeofHSCofthesematerialswithmoisturecontentandtemperature.

DSL014Prof.OlegPurskyKyivTarasShevchenkoUniversity,KyivUA03022,Pr.Glushkova6,Ukraine

ThermalExpansionEffectonHeatTransferinOrientationallyDisorderedPhasesofMolecularCrystals

O.I.Pursky1,V.A.Konstantinov21T.ShevchenkoKyivNationalUniversity,DepartmentofMolecularPhysics,

6,GlushkovAve.,Kyiv03680,Ukraine2B.VerkinInstituteforLowTemperaturePhysicsandEngineeringoftheNationalAcademyofScienceofUkraine,47Lenin

Ave.,Kharkov61103,Ukraine

Inpresentstudy,anattempthasbeenmadetofindathermalexpansioneffectonheattransferprocessesinorientationallydisordered(OD)phasesofmolecularcrystals.Discrepancies intemperaturedependencesof isobaricand isochoricthermalconductivity are connectedwith the thermal expansion of samples under investigation in isobaric case. To estimate theinfluenceofthermalexpansionontheheattransferinODphasesofmolecularcrystals,inthepresentinvestigationwehaveundertakentoseparatethephononphononandphononrotationcontributionstothetotalthermalresistanceofsolidSF6,CCl4(Ib) and C6H6, in both the isobaric and isochoric cases. For calculations,we used themodified version of reducedcoordinatesmethod[1].Itisimportanttonotethat,inthiscase,thereisnoneedtoresorttosomeapproximationmodelorother.On thebasisofour studies it seems justified toconclude that inODphasesofmolecularcrystals the thermalexpansioneffecttendsto increase inphononphononcomponentandgeneraldecrease inphononrotationalcomponentsofthetotalthermalresistance.


[1]O.I.Pursky,N.N.Zholonko,andV.A.Konstantinov,LowTemp.Phys.29,771(2003).DSL046Mr.AfshinFarahbakhshIslamicAzadUniversity,QuchanBranch,Iran

ConnectionofSingleWallCarbonNanotubetoAuLayerasaMatrixforBiosensors

A.Farahbakhsh1,a,H.A.Zamani2,b,S.K.Rahimi1,A.Niazmand1,c1DepartmentofChemicalEngineering,Quchanbranch,IslamicAzadUniversity,Quchan,Iran2DepartmentofAppliedChemistry,Quchanbranch,IslamicAzadUniversity,Quchan,[email protected],[email protected],[email protected]

Keywords:singlewalledcarbonnanotubes,glucose,glucoseoxidize,biosensorInthiswork,theconnectionofthesinglewallcarbonnanotube(SWCN)toAulayerbychemicalvapordeposition(CVD)wasinvestigated.ThebestarrangementofSWCNonAulayerwasobtainedtheshoulderstructure.Inthisarrangement,theironnanoparticlewasusedasabaseforthegrowingofAu/SWCN.ThepropertiesofthecreatedAu/SWCNwerecharacterizedbythescanningelectronmicroscopy (SEM)technique.TheconstructedAu/SWCNhas24nmdiameterand1015m length.Thissystemcanbeuseasasuitablematrixforthefabricationofavarietyofbiosensors.DSL201Mr.M.PirmohammadiResearchManagementofR&DDeputy,MapnaGroup,Tehran,Iran

EffectofVariableThermalConductivityonMagnetoConvectioninsideaPartitionedEnclosure

M.Pirmohammadi1,M.Ghassemi21ResearchManagementofR&DDeputy,MapnaGroup,Tehran,Iran

2MechanicalEngineeringDepartment,KNToosiUniversityofTechnology,Tehran,Iran

It iswellknownthatnaturalconvectionheattransfercanbedampedwiththehelpofamagneticfield.Employmentofanexternalmagnetic field has increasing applications inmaterialmanufacturing industry as a controlmechanism since theLorentz force suppresses the convection currents by reducing the velocities. Study and thorough understanding of themomentumandheattransferinsuchaprocessisimportantforthebettercontrolandqualityofthemanufacturedproducts[13].Magnetoconvectioninadifferentiallyheatedenclosurewithtworectangularadiabaticribs,symmetricallylocatedonhorizontalwalls(adiabaticwalls),iscarriedout.Thermalconductivityoffluidistemperaturedependent.ThegoverningnonlinearequationsaresolvedinatwodimensionaldomainusingacontrolvolumemethodandtheSIMPLERalgorithmforthevelocitypressurecouplingisemployed.Theresultswillbearepresentedinformofstreamlines,isothermsaswellasNusseltnumberforvariousRayleighnumber(Ra)andHartmannnumber(Ha).TheheattransferacrossthecavityfromhotwalltocoldwallbecomespoorforadecreaseinkandalsoSuppressionofconductionnearhotwallismorethanthatofconvection.FurthermoretheasHaincreasestheconvectionheattransfersuppressesandNusseltnumberdecrease.[1]I.E.Sarrisa;G.K.ZikosA.P.Grecosa;N.S.Vlachos,Numericalheattransfer,PartB,50,158180(2006)[2]M.Ghassemi,M.Pirmohammadi,GH.A.Sheikhzadeh,24thAnnualReviewof


ProgressinAppliedComputationalElectromagnetics,(2008).[3]M.Pirmohammadi,M.Ghassemi,andGH.A.Sheikhzadeh,IEEETransactionsonmagnetics,45(No.1),407411(2009).ProgressinAppliedComputationalElectromagnetics,(2008).[3]M.Pirmohammadi,M.Ghassemi,andGH.A.Sheikhzadeh,IEEETransactionsonmagnetics,45(No.1),407411(2009).DSL201Mr.M.Pirmohammadi

NumericalSimulationofNaturalConvectioninaMoldM.Pirmohammadi1,G.A.Sheikhzadeh2,M.Hamedi3

1ResearchManagementofR&DDeputy,MapnaGroup,Tehran,Iran2MechanicalEngineeringDepartment,UniversityofKashan,Kashan,Iran3MechanicalEngineeringDepartment,UniversityofTehran,Tehran,Iran

Natural convection heat transfer in differentially heated, partitioned cavities are encountered in various industrialapplications,suchassolidificationincastingandcrystalgrowth,heatingandventilatingoflivingspaces,fireinbuildings,andsolarthermalcollectorsystems.Inmanyapplications,forsomereasons,attachingrib(s)orbaffle(s)totheverticalwallortothehorizontalwall(s)partitionsthecavity.Recentlystudiesofheattransferandfluidflowcharacteristicsofpartitionedcavityhavecomeunderscrutinybothnumericallyandexperimentally[13].Numerical studyofnatural convectionheat transfer inside adifferentiallyheated square cavitywith adiabatichorizontalwalls and vertical isothermalwalls is investigated. Two insulated ribs are symmetrically located on horizontalwalls. Thegoverningnonlinearequationsare solved ina twodimensionaldomainusinga control volumemethodand theSIMPLERalgorithmforthevelocitypressurecouplingisemployed.Theresultswillbearepresentedinformofstreamlines,isothermsaswellasNusseltnumber forRayleighnumber ranging from104up to105. Special emphasis is given in the systematicanalysistodetailtheeffectsofthe lengthoftheribsontheflowstructureand isothermpattern.It isfoundthatthemeanNusseltnumberisaffectedbythelengthoftheribsandRayleighnumber.[1]A.N.Khalifa,Energyconversionandmanagement,42,491504(2001)[2]M.Ghassemi,M.Pirmohammadi,GH.A.Sheikhzadeh,WSEASTRANSACTIONSONFLUIDMECHANICS,2,6168(2007)[3]M.Pirmohammadi,M.Ghassemi,GH.A.Sheikhzadeh,ASME2008SummerHeatTransfer,August1014(2008),Jacksonville.FL.USADSL217Dr.I.I.HadzhidimovTechnicalUniversity,Varna,Bulgaria

HeatTurbomachinesaroundDiskSpacesMassandHeatTransferModeling

R.D.Yosifov1,N.A.Lazarovski1,D.G.Rusev1,I.I.Hadzhidimov1,D.P.Chakyrova11TechnicalUniversity,Varna,Bulgaria

Heatturbomachinesthermoaerodynamicprocessesanalysis is important fortheirdesignandexploitationconnectedwithreliableandfailurelessoperation inawidepowerrange.Thekinematicandthermodynamicparametersdistributionoftheworkfluidaroundheavyloadedturbinedisksandlabyrinthsealscausesconsiderableinfluenceupontheheatexchangeandenergyconvertionprocesses.Thisinfluenceappearsinseveralbasicdirections.Thesubjectofthepresentpaperismassandheattransferprocessanalysis,connectedwithworkfluidmotionintypicalcomplexclearancesbetweenrotorandstatorofdifferentsteamturbinestypes.Masstransferbyflowkinematicparameters,consumptionperformancesandresistances intheaxialandradialclearancesisdetermined.Theseparametersarearouddisks,diaphragms,internalandexternallabyrinth


seals,drums,equilibriumpiston(dummis),etc.fordifferentturbineconstructionelements.Bymeansofpumping,ejecting,reactive complex effectswith variable boundary conditions themass balance has been realized. This balance results onequilibriumpressuresofstreamlinedturbinepart.Thesepressuresareindividualforeveryexploitationregimeinaccordancewith the necessary power connected with mass consumption, steam distribution, seals wearing out degree, etc. Thepressures differences before and after the turbine disks and other unequilibrium rotor surfaces permit determining theinconstantaxialbearing loadings.Thebearingworksunderhighhydraulicpressures in lubricate layercontrolledbyturbineprotection and regulation system. Thermal turbine rotor load and expanding depending on temperature and velocitydistributionofabovementionedclearancesarecalculated.Thisresultsontheconvectiveheattransferfromtheworkfluidtotherotorelementsandconductive transfer throughtherotor (diskssealsbearingmodulus).Thenonuniformtemperaturefield isasignificantfactoractingbythermalexpansionsonaxial loadedrotorsystem.Prognosisofthermaltensionturbinerotors statement isaworldwideappliedpractice.Basedonour regionalconditionsbymeansofaxial forcesand thermalexpansionsdistributiondeterminationitispossibletoestimatetheturboaggregatesperformancereliabilityduringdesignorreconstructionaswellastheexploitationtimewithinthetotalpowerrange.DSL235Mr.ValerioTomarchioAlmaMaterStudiorum,UniversitdiBologna,DipartimentodiIngegneriaEnergetica,NucleareedelControlloAmbientale(DIENCA),LaboratoriodiMontecuccolino,ViadeiColli16.40136Bologna.Italy

MHDMixedConvectioninaVerticalCircularDuctwithaPeriodicWallTemperatureV.Tomarchio1,A.Barletta1

1AlmaMaterStudiorumUniversitdiBologna,DipartimentodiIngegneriaEnergetica,NucleareedelControlloAmbientale(DIENCA),LaboratoriodiMontecuccolino,ViadeiColli16.40136Bologna,

ITALY

Inthe lastyears,agrowinginteresthasbeenaddressedtothestudyofmagnethydrodynamiceffectsonmixedandnaturalconvective flows. Such interest in the topic is due to the large number of possible technological applications, like inmetallurgy,wherethequalityofthematerials,produced inaregimeofcontrolledcrystalgrowth,canbeinfluencedbytheeffectsofanexternalimposedmagneticfield.Recently,beingincreasedtheeffortstowardstherealizationofnuclearfusionmachines;MHDeffects in liquidmetal flowsarestudiedtodesignproperlycriticalcomponents (blankets)ofexperimentalreactors.Thispaperdescribestheeffectsofauniformhorizontalmagneticfieldonthemixedconvectiveflowofaconductivefluidinaverticalcircularduct.Thestudyherebypresentedassumesasteadyperiodicregimeinducedbythewalltemperatureoftheduct,which isuniformandvaryingsinusoidallywithtime.The localbalanceequationsofmomentumandenergy,togetherwiththeconservationofelectriccharge,willbesolvednumerically.Thetemperature,velocityandelectricpotentialfieldswillbedecomposedinasteadyandanoscillatingcomponentevaluatedseparately.Theductwallswillbeassumedasperfectlyinsulating.Thispapercontinues theexperiencepreviouslygathered in theanalysisofmixedconvection insteadyperiodicregimewithandwithoutMHDeffects[1,2].[1]A.Barletta,E.Zanchini,Timeperiodiclaminarmixedconvectioninaninclinedchannel,Int.J.HeatandMassTransfer,46,pp.551563,2003.[2]V.Tomarchio,A.Barletta:EffettiMHDsullaconvezionemistaentrouncanalerettangolareinregimeperiodicostabilizzato,AttidelXXVICongressoNazionaleUIT,335340(Palermo,2008).DSL240Dr.GhanbaraliSheikhzadeh


MechanicalEngineeringDepartment,UniversityofKashan,Kashan,Iran

EffectofaShieldonMixedConvectioninaRectangularEnclosurewithMovingColdSideWallsandaHeatSourceontheBottomWall

GH.A.Sheikhzadeh1,S.H.Moosavi1,N.Sadooghi11DepartmentofMechanicalEngineering,UniversityofKashan,Kashan,Iran

Theelectroniccomponentsaretreatedasheatsourcesembedded inflatsurfaces[1].Anumberofnumericalstudieshavebeen carried out to investigate the mixed convective cooling of heat dissipating electronic components, located in arectangularenclosureandcooledbyanexternalflowofair[24].In thiswork, themixed conventionofair insidea rectangular cavity is studiednumerically.The cavityhas cold sidewallsmovingataconstantspeed.Aconstantfluxheatsourceisattachedtothebottomwallofthecavity.Athinthermalshieldislocatedataspecificdistanceabovetheheatsource.Thetopandtheremainingpartsofthebottomwallsareadiabatic.Thegoverning equations are solved using appropriate numericalmethods. To solve for the velocity and pressure field theSIMPLERalgorithmhasbeenemployed.TheresultingsetofalgebraicequationshasbeensolvedusingalinebylineiterationandTDMAscheme.Theresultsarepresentedintheformofstreamlineandisothermcontours.TheRichardsonnumberhasbeenchosenasacriteriontomonitortheeffectsofsidewallsvelocitiesontheflowfieldandheattransferinsidethecavity.Aparametricstudyhasbeenconductedand theeffectsofheatsource length, its locationand the shielddistance from thesourceontheheattransferhavebeeninvestigated.Theresultsshowthattheheatdissipationincreasesastheheatsourceand the shield aremovedup toa certaindistance towardseither sidewall.However,moving thembeyond this limitingdistanceresults inthereductionofheatdissipation. It isshownthatthepresenceofshieldresults inthereductionoftheheat transfer coefficient.However, for thenormalizeddistanceof the shield from theheat sourcegreater than0.45, theshieldseffectonthereductionoftheheattransfercoefficientislessthan10%.Keywords:NumericalStudy,RectangularCavity,HeatSource,MixedConvection,Shield[1]F.P.Incropera,J.HeatTransfer,110,1097,(1988).[2]E.Panpanicolaou,Y.Jaluria,Numer.HeatTransfer,PartA23,463,(1993).[3]E.Panpanicolaou,Y.Jaluria,J.HeatTransfer,116,960,(1994).[4]G.Guo,M.A.R.Sharif,InternationalJournalofThermalSciences,43,465,(2004).DSL267Prof.GilmarGuimaresFederalUniversityofUberlndia,FEMECUFU,Uberlndia,MG,Brazil

AnalysisoftheEffectofCuttingParametersontheCuttingEdgeTemperaturesUsingInverseHeatConductionTechnique

M.R.Santos1,S.M.MLimaeSilva2,Guimares,G.1,S.R.Carvalho11FederalUniversityofUberlndia,FEMECUFU,Uberlndia,MG,Brazil

2FederalUniversityofItajub,IEMUNIFEI,Itajub,MG,BrazilDuring themachining process, a considerable amount of themachining energy is transformed into heat due to plasticdeformationof theworkpiecesurface, the frictionof thechipon the tool faceand the frictionbetween the tooland theworkpiece.High temperaturesaregenerated in the regionof the tool cuttingedge,and these temperatureshaveaveryimportantinfluenceontherateofwearofthecuttingtoolandonthefrictionbetweenthechipandthetoolandmainlyonthe tool life.TheexperimentsofTosunandOzler [1]shown that the tool life increasessignificantlywhen themanganesesteelspecimensareheatedduringmachining.Theyconcludedthat4000Cistheoptimumheatingtemperatureconsideringthemicrostructureoftheworkpiecestudied.Thatworkdemonstratesthegreatimportanceofthetemperaturedistributionattheinterfaceinvariousmachiningconditions.Thispapermakesanexperimentalandnumericalinvestigationofdifferentfactorswhichinfluencethetemperaturedistributionatthehighspeedsteel(AISIM32C)toolrakefaceduringmachiningofa(ABNT12L14) steelworkpiece.The temperaturedistributionwaspredictedusing finite volumeelementswithan inverse


problem procedure. The inverse technique uses numerical and experimental results for both heat flux and temperatureestimation.Temperaturesweremeasuredbythermocouplesatpositionsdistantfromtheregionof interest.Heatfluxesatthetoolworkpieceinterfaceareestimatedusingtheseremotelymeasuredtemperatures.Experimentswereperformedtostudytheeffectofcuttingparametersonthecuttingedgetemperature.[1]N.TosunandL.Ozler,JournalofMaterialsProcessingTechnology,124,99(2002)DSL280Mr.ArashJafariUniversitiTeknologiMalaysia,81310UTMSkudai,Johor,Malaysia

OptimizationofaCircularMicrochannelHeatSinkUsingEntropyGenerationMinimizationMethod

A.Jafari1,AssociatedProf.Dr.N.MohdGhazali21UniversitiTeknologiMalaysia,81310UTMSkudai,Johor,Malaysia

New advances in micro and nano scales are being realized and the contributions of micro and nano heatdissipation devices are of high importance in this novel technology development. Past studies showed thatmicrochannel design depends on its thermal resistance and pressure drop. However, entropy generationminimization (EGM) as a new optimization theory stated that the rate of entropy generation should be alsooptimized.ApplicationofEGMinmicrochannelheatsinkdesignisreviewedanddiscussed.UsingEGM,majorityofthepublishedinvestigationsareconductedbasedonrectangularcrosssectionmicrochannel.Latestprinciplesforderivingtheentropygenerationcorrelationsarediscussedtopresenthowthisapproachcanbeachieved.ThepresentstudyinvolvesanoptimizationprocedureusingEGMmethodandderivestheentropygenerationrateinncircularmicrochannelheatsinkbaseduponthermalresistanceandpressuredropsimultaneously.Theequationsare solved usingMATLAB and the obtained results are compared to the past studies. The effect of channeldiameter and number of channels on the entropy generation rate, Reynolds number, thermal resistance andpressuredropisinvestigated.Analyticalcorrelationsareutilizedforheattransferandfrictioncoefficients.[1]A.Bejan,JournalofAppliedPhysics.Vol.79,pp11911218(1996).[2]C.Y.Yang,andT.Y.Lin,ExperimentalThermalandFluidScience,Vol.32,pp432439(2007).[3]J.Li,andG.P.Peterson,IEEETransactions,Vol.29,Issue1,pp145154(2006).[4]P.S.Lee,andS.V.Garimella,InternationalJournalofHeatandMassTransfer,Vol.49,pp30603067(2006).[5]W.A.Khan,M.M.Yovanovich,andJ.R.Culham,SemiconductorThermalMeasurementandManagementSymposium,pp7886(2006).[6]A.Bejan,ConvectionHeatTransfer,thirdedition,pp.1119,(Wiley,NewYork,2004)DSL300Prof.AssuntaAndreozziDETEC,UniversitdegliStudiFedericoII,PiazzaleTecchio80,80125Napoli,Italy

AnalyticalSolutionforQuasiSteadyStateTwoDimensionalTemperatureDistributioninaFiniteDepthSolidwithaMovingHeatSource

A.Andreozzi1,B.Buonomo2,O.Manca21DETEC,UniversitdegliStudiFedericoII,PiazzaleTecchio80,80125Napoli,Italy2DIAM,SecondaUniversitdegliStudidiNapoli,ViaRoma29,81031Aversa,Italy


Movingheat sourcesare frequentlyused inmanymanufacturingprocesses, includingwelding,cutting,heat treatmentofmetalandofelectroniccomponents.This isdue to theirability toconcentratehighpowersover small localizedareas. Inparticular,manystudieshavebeencarriedouttopredicttemperaturefieldsinsuchprocesses.Even ifnumericalmethodsarepowerfultoolstosolvethethermalmodelsdescribingtheprocessingsolid,especiallywhendealingwithcomplexgeometries,nonlinearboundaryconditionsandtemperaturedependentthermalproperties,analyticalapproaches are still very useful. This is due to the need to provide (a) good insight into the significance of parametersaffectingtheprocessand (b)analyticalsolutions forvalidationofnumericalcodes. Inordertopredictthebehaviorofthematerialafterthemanufacturingprocessandtosimplifythephysicalmodel, it is importanttoevaluatethemostaffectingparametersinvolvedintheparticularprocessinsuchawayastooptimizethematerialprocessing.ThePecletnumber,whichcompares the thermal diffusion term in the direction of the motion to the convective component, is the mainnondimensionalparametergoverningtheheattransfermechanisminthesystem.Inthispaperananalyticalsolutionofatwodimensionalquasisteadystatethermalconductivemodel inasolidwithfinitedepthand infinite lengthunderamovingheatsource isevaluated.Thespot is indefinitealongthedirectionnormaltothemotion and the distribution along themoving direction is a linear combination of a gaussian and donut function. Theevaluationof thesolution isobtainedbymeansoftheGreen functionmethod.Results foreachPecletnumberaregiven.Temperatureprofilesalongthemovingdirectionandthedepthandtemperaturefieldsarepresented.DSL343Mr.WILLYBASTINDepartmentofMechanicalEngineering,NationalInstituteofTechnology,Calicut

ConvectiveHeatTransferStudiesofaCylindricalHeaterusingDigitalInterferometry

WillyBastin1*andV.Sajith11DepartmentofMechanicalEngineering,NationalInstituteofTechnology,Calicut

*email:[email protected]

The free convection studies from cylindrical surfaces such as thin wires, tubes to the surrounding medium has gottremendousapplicationinengineeringfieldascorrespondingheattransfercoefficientsareessentiallyrequiredforthedesignofheattransferequipments.Steadystateaswellasthetransientheattransferstudiesessentiallyrequiresthetemperaturedistributioninthemediumsurroundingtheheatdissipatingsurface.Thetraditionalmethodoftemperaturemeasurementisusingthethermocoupleprobe,andforobtainingthetemperaturedistributioninthemediumeitheranumberofprobesoramovingprobe technique is required. Bothof thesemethodsdisturb the flow fieldandbringerrors in themeasurement.Henceameasurementtechniquewhichdoesnotaffecttheflowfieldisalwayspreferableinsuchsituations.Opticalmethodscan be effectively used, due to their nonintrusive nature, good sensitivity andmeasurement accuracy.Measurementmethodssuchas interferometryareextremelyusefultools forvisualizingtherealtimetemperaturedistributionsoverthewholefieldthroughinstantaneousphotographsaswellasinfollowingtransientphenomenathroughcontinuousrecordingofvisualization patterns. The present investigation is aimed at developing an interferometricmethod for convective heattransfermeasurementinairsurroundingacylindricalheatersurface.Thetestspecimenusedhereisacylindricalheaterof2cm diameter and 3 cm length. Heater coil is kept inside a steel tube and is supplied with stabilized AC through anautotransformerforcontrollingtheheatoutput.AMachZehnder interferometricarrangementhasbeenused inthiswork,to obtain the temperature distributions in air surrounding the heater surface. Interferometric methods utilize theinterferenceof two coherent lightbeams formeasurementof temperaturedistributionsandheat transfer inananalysisdomain, and depend on the additional phase lag introducedwhen these light beams pass through regions of differentdensitiesandrefractive indicescausedbythetemperaturefield.ThefringepatternsaregrabbedusinganAVTMarlinCCDcamera, and the AVT Fire package software. TheMZI set up has been validated using a vertical heater plate and theexperimentalresultsarecomparedwiththetheoreticalresults.Theopticalcomponentsarearrangedinsuchawaytoobtainparallelwedgefringesinitially.Digitalimageprocessingtechniquehasbeenusedforanalyzingthefringepatterns.Themoirfringes, ie isothermsaroundthecylindricalheaterplateareobtainedbythedigitalsubtractionofthe initialparallelfringesfromthedeformedfringes,whichcontainstheinformationofthetemperaturedistribution.Thetemperaturecorrespondingto the isotherms are obtained by interferometric relations, knowing the reference temperature,measured using T typethermocouple.The temperaturegradient, localheat transfer coefficientaswellasheat fluxatvarious locationalong thecircumferenceofthecylindricalheaterareobtainedfromthetemperaturedistributionintheradialdirection.Thevariation


oftheheattransfercoefficientalongthecircumferenceofthecylindricalheatersurfaceatvariousangleshasbeenplotted.Digitalinterferometryhasbeeneffectivelyutilizedtostudythesteadystateaswellastransientheattransfercharacteristicsaroundthecylindricalheater.REFERENCES[1] J.V Herraez, R Belda, A study of free convection in air around horizontal cylinders of different diameters based onholographic interferometry. Temperature field equations and heat transfer coefficients. International journal ofthermalsciences(2002)App261267[2] T. Yousefi ,M. Ashjaee , Experimental study of natural convection heat transfer from vertical array of isothermalhorizontal elliptic cylinders, Experimental Thermal and Fluid Science 32 (2007) pp:614623[3]R.Ghazy,B.ElBaradie,A.ElShaer,F.ElMekawey,MeasurementsoftherefractiveindicesandrefractiveindexincrementofasyntheticPMMAsolutionsat488nm.Optics&LaserTechnology,31(1999)[4]ZhiCheng Jian,ChengChihHsu,DerChinSuI,), Improved technique formeasuring refractive indexand thicknessofatransparentplate.OpticsCommunications,226(2003),pp:35140[5] Naylor,D.,2003,Recent developments in themeasurement of convective heat transfer rates by laser interferometry,Int.J.ofHeatandFluidFlow,24,pp:.345355[6]M.Ashjaee,A.H.Eshtiaghi,M.Yaghoubi and T.Yousefi, Experimental investigation on free convection from ahorizontalcylinderbeneathanadiabaticceiling,ExperimentalThermalandFluidScience,32(2007),pp:614623DSL369Dr.ElenaCampagnoliPolitecnicodiTorino,DipartimentodiEnergetica,C.soDucadegliAbruzzi24,10129Torino

ThermaldiffusivityoftraditionalandinnovativesheetsteelsE.Campagnoli1,P.Matteis2,G.Scavino2

1PolitecnicodiTorino,DipartimentodiEnergetica,C.soDucadegliAbruzzi24,10129Torino1PolitecnicodiTorino,DipartimentodiScienzadeiMaterialieIngegneriaChimica,C.soDucadegliAbruzzi24,10129Torino

During the last years, in the automotive field the low carbon steels, used for the production of the carbodiesby deepdrawing,aregraduallysubstitutedbymoreadvancedhighstrengthsteelsinordertoreducevehicleweight.Independentoftheusedsteel,thedrawncarbodycomponentsarejoinedtogetherthroughaweldingprocessanditiswellknownthattheweldedpointsundergoareductionofthelocaltensilestrengthvalue.Indevelopinganaccurateweldingprocessmodel,abletoindicatewhicharetheoptimizedprocessparametersandabletopredictthefinallocalmicrostructure,asignificantimprovementcanbegivenbytheknowledgeoftheweldedsteelsthermaldiffusivityatdifferenttemperatures.Thelaserflashmethodhasbeenusedinordertomeasurethethermaldiffusivityoftwotraditionaldeepdrawingsteels,twohighstrengthsteelsalready incommonusage, i.e.aDualPhase (DP)steelandaTRansformation InducedPlasticity (TRIP)steel,andoneexperimentalhighMnausteniticTWIP(TwinningInducedPlasticity)steel.Theresultsshowthatthelowcarbonsteels,atlowtemperatures,haveathermaldiffusivitythatis45timeslargerthentheTWIPsteel.TheirthermaldiffusivitydecreasesbyincreasingtemperaturewhiletheTWIPsteelshowsanoppositebehaviour,albeitwitha lesserslope,sothatabove700CtheTWIPthermaldiffusivityresultstobe larger.ThedifferentbehaviouroftheTWIPsteelinrespecttothetraditionalferriticdeepdrawingsteelsarisesfromitsausteniticstructure.Moreover,theDPandTRIPsteelsshowintermediatevalues,theirdiffusivitybeinglowerthanthatofthetraditionaldeepdrawingsteels;thislatterfactprobablyarisesfromtheirhigheralloycontentandmorecomplexmicrostructure.DSL396Mr.T.AnithaManiDepartmentofChemicalEngineering,AnnaUniversity,Chennai,TamilNadu,India


EFFECTIVEHEATTRANSFERINCRUDEOILREFINERYHEATEXCHANGERBYRETROFITDESIGN

T.AnithaMani1,N.Gayathri1,N.Janani1UndertheGuidanceofDr.N.NagendraGandhi1

1DepartmentofChemicalEngineering,AnnaUniversity,Chennai,TamilNadu,India

Fouling refers to the accumulationofundesirableproductson the surfaceof heat exchangeroffering resistance to heattransfer. Reduced heat recovery and increased pressure drop are the twomajor aspects of fouling on a preheat trainoperation.Thedevelopmentofthermalandpressuredropmodelsforcrudeoilfoulinghasenabledtoperformanalysisandtocomparevariousdesignoptions.Theuseoffoulingfactorsinheatexchangerdesignandlackofappreciationoffoulingintraditionalpinchapproachhasresulted inbadlydesignedcrudepreheatnetworksthatareexpensivetomaintain.Foulingmodel isappliedattwo levels1.Assessmentofaddingextraareato individualexchanger2.Designofacompletenetworkusingmodifiedtemperaturefieldplot.Applicationtoarefinerycasestudyshowedthatbothattheexchangerandnetworklevelsdesigning formaximumheatrecoveryusingtraditionalpinchapproachresults in leastefficientheatrecoveryoveratime period when fouling occurs.REFERENCES:[1]Atkins,G.T.,1962,Whattodoabouthighcokingrates,Petro/ChemEngineer,Vol.34,pp2025.[2]Kern,D.Q.,1988,ProcessHeatTransfer,McGrawHill,NKnudsen,J.G.,Lin,D.andEbert,W.A.,1997,Thedeterminationofthethresholdfoulingcurveforacrudeoil,in:[3]Wilson,D.I.andPol

Öchsner, g. murch, a. shokuhfar j. delgado abstract book · a. Öchsner, g. murch, a. shokuhfar...

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