简介:有沿着一张拉长的表的混合传送对流的非牛顿的液体的不可压缩的流动被分析。热转移现象通过热放射被讨论。融化的热转移和热产生/吸收的效果也被拿。合适的转变被利用达到非线性的平常的微分表情。会聚的系列答案被介绍。液体流动,温度,和表面热转移率图形地被检验。当时,松驰时间什么时候增加,被观察速度减少当延迟时间是不变的时,增加。当放射参数增加时,结果也表明温度分发减少。
简介:Thethermaldistortionofanopticalreflectorsurfaceduetothechangingsunlightinaspaceenvironmentwillcauseshiftandspreadingofitsreflectedfocusandtherebyinfluencetheperformanceofspace-to-groundlasercommunicationlinks.Basedonthecharacteristicsofaloworbitsatellite,thenormalshiftofaplanmirrorcausedbythermaldistortionisanalyzedwiththesoftwareoftheANSYSoffiniteelementanalysis.Ageneralexpressionofthetransmittedbeamfromadistortedreflectorsurfaceandacountingformulafortheshiftsofthefocuscenterbeforeandafterthermaldistortionarededuced.Theresultofsimulationshowsthatthemagnitudeorderofthenormalshiftoftheantennamirrorsurfacecanbeashighastensofμrad.Theworsethemirrorthermaldistortionis,thelargertheshiftofthereceivedfocuscenteris.Andthechangeoftheshiftsdoesnotobeyalinearrule.
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简介:Theplasmasprayedthermalbarriercoating(TBC)consistsofNiCrAlYbondcoatingandyttriapartiallystabilizedzirconia(YPSZ)topcoating.NiCrAlYcoatingmainlycontainsNisolidsolutionwithfacecenteredcubiclattice,Al2O3oxidesandpores.ThemostobviousfeatureofYPSZcoatingwithtetragonalzirconiaisalotofverticalmicrocracksinthiscoating.ThethermalinsulationcapabilityoftheTBCincreasedwithanincreaseinYPSZcoatingthickness,thetemperaturedropacrosstheTBCincreasingfrom60℃to92℃withincreasingYPSZcoatingthicknessfrom100μmto500μm.ThethermalshockresistanceoftheTBCdecreasedwithincreasingYPSZcoatingthicknessandcracksinitiatedmainlyinoriginalverticalmicrocracktipsoftheYPSZcoatingandpropagatednotonlyalongYPSZcoating/NiCrAlYcoatinginterfacebutalsothroughNiCrAlYcoating.TheoxidationprocessoftheTBCat1200℃canbedividedintotwostages:traasieatoxidationstagewithrapidoxidationrateandsteadyoxidationstagewithslowoxidation.Theirtransitiontimewasabout10hours.Theweightgainfor100hourswas3.222mg/mm^2.ItisfavorabletoincreaseYPSZcoatingtoughnessandtodecreasetheporesandoxidesoftheTBCsystemforimprovingthermalshockresistanceandoxidationresistanceoftheTBC.
简介:Analternateyetgeneralformoftheclassicaleffectivethermalconductivitymodel(Maxwellmodel)fortwo-phaseporousmaterialsispresented,servinganexplicitthermo-physicalbasis.Itisdemonstratedthatthereducedeffectivethermalconductivityoftheporousmediaduetonon-conductingporeinclusionsiscausedbythemechanismofthermalstretching,whichisacombinationofreducedeffectiveheatflowareaandelongatedheattransferdistance(thermaltortuosity).
简介:TheresponseoftheSouthChinaSea(SCS)toTyphoonChanchu(2006)wasexaminedusingtheMM5andPOMmodel.InthePOMmodel,seasurfaceboundaryconditionswereforcedbythesimulationwindfieldfromMM5,thevelocityforcingwasintroducedintheeasternboundaryandthecomputationalschemesofheatfluxesatthesurfacewereintroduced.Comparisonwiththeobservationdatashowsthatthesimulatedresultsarereliable.IntheresponseprocessoftheSCStoTyphoonChanchu,theinfluenceoftheheatfluxesonthermalstructureoftheSCSwasregionallydifferent.Strongwindforcingwouldleadtoupwellingphenomenoninthelateralboundaryofdeepwaterbasin.Furthermore,theEkmanpumpingtheorywasusedtodiscusssubsurfaceupwellinganddownwellingphenomenonintyphoonforcedstage.
简介:WatertankexperimentswerecarriedouttoinvestigatethethermalconvectionduetothebottomheatinginanasymmetricalvalleyunderneutralandstablystratifiedapproachflowswiththeParticleImageVelometry(PIV)visualizationtechnique.Intheneutralstratificationapproachflow,theascendingdraftinducedbybottomheatingismainlylocatedinthecenterofthevalleyincalmambientwind.However,withambientwindflow,thethermalconvectionisshiftedleeward,andthedescendingdraftislocatedontheleewardsideofthevalley,whiletheascendingdraftislocatedonthewindwardside.Thedescendingdraftisminorlyturbulentandorganized,whiletheascendingdraftishighlyturbulent.Withtheincreaseofthetowingspeed,thedescendingandascendingdraftsinducedbythemechanicalelevationbegintoplayamoredominantroleinthevalleyflow,whiletheroleofthethermalconvectioninthevalleyairflowbecomeslimited.Inthestablestratificationapproachflow,thethermalconvectionislimitedbythestablestratificationandnodistinctcirculationisformedincalmambientwind.Withambientwind,agravitywaveappearsintheupperlayerinthevalley.Withtheincreaseoftheambientwindspeed,agravitywaveplaysanimportantroleinthevalleyflow,andthelocationandintensityofthethermalconvectionarealsomodulatedbythegravityinternalwaves.Thethermalconvectionhasdifficultypenetratingtheupperstablelayer.Itsexchangeislimitedbetweentheairintheupperlayerandthatinthelowerlayerinthevalley,anditisadversetothediffusionofpollutantsinthevalley.
简介:Opto-thermaltransientemissionradiometry(OTTER)isainfraredremotesensingtechnique,whichhasbeensuccessfullyusedininvivoskinmoisturecontentandskinmoisturedepthprofilingmeasurements.Inpresentpaper,weextendthismoisturecontentmeasurementcapabilitytoanalyzethemoisturecontentoffruit(tomato,grape,etc.)skins,andtostudytherelationshipbetweenfruitsripeningprocessandtheirsurfacemoistureandmoisturedepthprofiles.
简介:Inthispaper,varioustechniquesincludingBET,XRD,SEMandXPSwereusedtostudythesinteringofpureandLa2O3-dopedtitania.Theexperimentalresultsshowthatsinteringoftitaniaproceedsviavolumediffu-sion.Addingoflanthanumoxidedecreasestherateofsinteringandhindersthephasetransitionfromanatasetorutilecrystalbystrongsurfaceinteractionbetweenthemixedcrystals(La4Ti9O24,La0.66TiO2.99)andTiO2.
简介:Toimprovemicrowavehyperthevmiaincancertherapy,thethermaleffectoffer-rimagneticresonance(FMR)duringmicrowaveirradiationwasstudied.Resonanttemperatureelevation(RTE)ofsinglecrystalgrainandpolycrystalpowderofresonantmediawasmeasuredaloneandinimitativemuscleandeggwhiteandinmice.TheresultsindicatedthattheRTEproducedbyFMRcouldbeusedtoimprovepenetrationdeepness,heatingselectivityandtemperaturedistributionofmicrowavehyperthermiaincancertreatment.ItwasexpectedthatthepotentialfunctionoftheFMRheatingsystemwouldbeex-ploitedgreatlyforcancertherapy,andthenmagneticallyguidedmicrowavehyperthermiathera-py,chemotherapy,radiotherapyandimmunotherapymighthecombinedmultiplywithinthissys-tembymeansofthestaticmagneticfield(SMF)andmagneticmicrocarrier.Limitationofreso-nantheatingwasalsodiscussedinthispaper.