力學(xué)大會2015集ms4524超臨界壓力下低溫甲烷納米流體湍流傳熱數(shù)值模擬研究

阮波1，高效偉1，孟華Email:低溫甲烷納米流體在圓形冷卻管道內(nèi)超臨界壓力下的湍流傳熱性能進行了數(shù)值模擬發(fā)現(xiàn)在超臨界壓力下加入納米顆粒能提高甲烷的對流傳熱性能，且對流換熱數(shù)隨著O體積分?jǐn)?shù)的增加而增大。當(dāng)加入體積分?jǐn)?shù)為3%的傳熱性能提高約80%。本文的研究工作有助于增進對納米流體在超臨界壓力下流動傳熱特性和強化傳熱超臨界壓力，湍流換熱，納米流體，數(shù)值模納米流體，是指以一定的方式和比例在流體基液中添加納米級金屬或金屬氧化物顆粒形成的新的傳熱工質(zhì)?？茖W(xué)研究工作者對納米流體的傳熱性能進行了多項研究，并取得了重大進謝華清等1建立對流換熱測試系統(tǒng)研究了納米粒子懸浮介質(zhì)的平均1中國博士后科學(xué)基金資助項銅熱物理性超臨界壓力下，流體熱物性變化劇烈，因此準(zhǔn)確計算流體的熱物性是開展超臨界difiedBenedict-Webb-Redlich-得到驗證。計算過程中用到甲烷的熱動力參數(shù)如表1所示。1甲烷的熱動力學(xué)參數(shù)

2CuO納米顆粒的熱物性

Density,

Thermalconductivity,

Specificheat 30-

Wolfstein模型對流動進行直接計算。通過網(wǎng)格獨立性分析，確定了70×8000（r×3所示的計算工況下的湍流傳熱進行了數(shù)值模擬3計p0, qw, u0, 管內(nèi)流體平均溫度變化如從5可以看出，隨著CuO顆粒體積對流換熱Nusselt數(shù)逐漸增大。與純甲烷基液相比，當(dāng)=3.0%時Nusselt數(shù)最大能提高約80%。性變化非常劇烈。如圖6-圖6近壁面處體積熱容的變7近壁面處熱傳導(dǎo)系數(shù)的變化8近壁面處黏性系數(shù)的變化如9所示，純甲烷液體(=0%)在壁面附近的流速大于管道中心主流區(qū)的流速，在r方向上的域的傳熱惡化現(xiàn)象。進一步增加CuO納米顆粒的體積分?jǐn)?shù)(=1%、3%)，隨著M型速度分本文對謝華清奚同庚王錦昌納米流體介質(zhì)導(dǎo)熱機理初探.物理學(xué)報20036(6)1444-XuanY.,LiQ.Investigationonconvectiveheattransferandflowfeaturesofnanofluids.ASMEJ.HeatTransfer,2003,125:151-155.LiQ.,XuanY.ConvectiveheattransferandflowcharacteristicsofCu-waternanofluid.ScienceinChina(SeriesE),2002,45(4):408-416.HerisS.Z.,EsfahanyM.N.,EtemadS.G.ExperimentalinvestigationofconvectiveheattransferofAl2O3-waternanofluidincirculartube.InternationalJournalofHeatandFluidFlow,2007,28:203-210.NguyenC.T.,DesgrangesF.,GalanisN.,etal.ViscositydataforAl2O3-waternanofluid-hysteresis:isheattransferenhancementusingnanofluidsreliable?InternationalJournalofThermalSciences,2008,47:103-111.Khoshvaght-AliabadiM.,HormoziF.Heattransferenhancementbyusingcopper–waternanofluidflowinsideapinchannel.ExperimentalHeatTransfer,2015,28:446-463.HeidaryH.,HosseiniR.,PirmohammadiM.,KermaniM.J.Numericalstudyofmagneticfieldeffectonnano-fluidforcedconvectioninachannel.JournalofMagnetismandMagneticMaterials,2015,374:11–17.MengH.,YangV.Aunifiedtreatmentofgeneralfluidthermodynamicsanditsapplicationtoapreconditioningscheme,JournalofComputationalPhysics,2003,189:277-304.MengH.,HsiaoG.C.,YangV.,etal.Transportanddynamicsofliquidoxygendropletsinsupercriticalhydrogenstreams.JournalofFluidMechanics,2005,527:115-139.WangY.Z.,HuaY.X.,MengH.Numericalstudyofsupercriticalturbulentconvectiveheattransferofcryogenic-propellantmethane.JournalofThermophysicsandHeatTransfer,2010,24,490-500.RuanB.,MengH.,YangV.Simplificationofpyrolyticreactionmechanismandturbulentheattransferofn-decaneatsupercriticalpressures.InternationalJournalofHeatandMassTransfer2014,69:455–463.ReidR.C.,PrausnitzJ.M.,PolingB.E.Thepropertiesofgasesandliquids,4thEdition,McGraw-Hill,RashidiM.M.,AbelmanS.,FreidooniMehrN.EntropygenerationinsteadyMHDflowduetoarotatingporousdiskinananofluid.InternationalJournalofHeatandMassTransfer,2013,62:515–525.FotukianS.M.,EsfahanyNasrM.ExperimentalstudyofturbulentconvectiveheattransferandpressuredropofdiluteCuO/waternanofluidinsideacirculartube.InternationalCommunicationsinHeatandMassTransfer,2010,37:214–WenD.,Ding,Y.Experimentalinvestigationintoconvectiveheattransferofnanofluidattheentrancerejoinunderlaminarflowconditions.InternationalJournalofHeatandMassTransfer,2004,47(24):5181–5188.Xuan,Y.,Roetzel,W.Conceptionsforheattransfercorrelationofnano-fluids.InternationalJournalofHeatandMassTransfer,2000,43:3701–3707.KooJ.,KleinstreuerC.Laminarnanofluidflowinmicroheatsinks.InternationalJournalofHeatandMassTransfer,2005,48:2652–2661.PizzarelliM.,UrbanoA.,NasutiF.Numericalanalysisofdeteriorationinheattransfertonear-criticalrocketpropellants.NumericalHeatTransfer,PartA,2010,57(5):297-314DuffeyR.,PioroI.Experimentalheattransferofsupercriticalcarbondioxideflowinginsidechannels(survey).NuclearEngineeringandDesign,2005,235:913–924.LeeS.,HowellJ.Turbulentdevelopingconvectiveheattransferinatubeforfluidsnearthecriticalpoint.InternationalJournalofHeatandMassTransfer,1998,41:1205–1218.NUMERICALSTUDYOFTURBULENTHEATTRANSFEROFCuO/METHANENANOFLUIDATSUPERCRITICALPRESSURESRUANBo1,GAOXiaowei1,MENG(1StateKeyLaboratoryofStructuralAnalysisforIndustrialEquipment,SchoolofAeronauticsandAstronautics,DalianUniversityofTechnology,Dalian,Liaoning116024,China)(2SchoolofAeronauticsandAstronautics,ZhejiangUniversity,Hangzhou,Zhejiang310027,Email:menghua@zjuAbstractNano-scaleparticlescanbeaddedtothehydrocarbonfuelstoimprovetheperformanceofconvectiveheattransferinregenerativecoolingsystemofhypersonicaircraft.TurbulentconvectiveheattransferofCuO/methanenanofluidflowinginsideacirculartubeatasupercriticalpressurehasbeennumericallyanalyzedinthiswork.Significantenhancementofheattransferhasbeenobserved.Furthermore,theNusseltnumberincreaseswiththevolumeconcentrationofCuOparticle,80%increaseforvol.3%CuOover