外文翻譯-汽車散熱器性能

畢業(yè)設(shè)計（論文）外文參考資料及譯文譯文題目：AutomotiveRadiatorPerformance汽車散熱器性能學(xué)生姓名：學(xué)號：專業(yè)：所在學(xué)院：指導(dǎo)教師：職稱：20xx年2月27日

AutomotiveRadiatorPerformanceAbstract—Automotiveenginecoolingsystemtakescareofexcessheatproducedduringengineoperation.Itregulatesenginesurfacetemperatureforengineoptimumefficiency.Recentadvancementinengineforpowerforcedenginecoolingsystemtodevelopnewstrategiestoimproveitsperformanceefficiency.Alsotoreducefuelconsumptionalongwithcontrollingengineemissiontomitigateenvironmentalpollutionnorms.Thispaperthrowslightonparameterswhichinfluenceradiatorperformancealongwithreviewssomeoftheconventionalandmodernapproachestoenhanceradiatorperformance.IndexTerms—Automotiveenginecoolingsystem,Performance,RadiatorI.INTRODUCTIONAutomotiveenginecoolingsystemtakescareofexcessheatproducedduringengineoperation.Itregulatesenginesurfacetemperatureforengineoptimumefficiency.Mostautomotiveenginecoolingsystemsconsistoftheradiator,waterpump,coolingfan,pressurecapandthermostat.Radiatoristheprimecomponentofthesystem.Radiatorisaheatexchangerthatremovesheatfromenginecoolantpassingthroughit.Heatistransferredfromhotcoolanttooutsideair.Radiatorassemblyconsistsofthreemainpartscore,inlettankandoutlettank.Corehastwosetsofpassage,asetoftubesandasetoffins.Coolantflowsthroughtubesandairflowsbetweenfins.Thehotcoolantsendsheatthroughtubestofins.Outsideairpassingbetweenfinspickupsandcarriesawayheat.ManuscriptreceivedFebruary,2013.PawanS.Amrutkar,DepartmentofMechanicalEngineering,SinhgadAcademyofEngineering,UniversityofPune,India.SangramR.Patil,DepartmentofMechanicalEngineering,SinhgadAcademyofEngineering,UniversityofPune,India.Performanceofenginecoolingsystemisinfluencedbyfactorslikeairandcoolantmassflowrate,airinlettemperature,coolantfluid,fintype,finpitch,tubetypeandtubepitchetc.Whiledesigningcoolingsystemthreeworstconditionsconsideredbasedonaboveparameters.Highaltitude:Athighaltitude,airdensitybecomeslowandhenceaffectsairmassflowrate.Summerconditions:Duringsummersurroundingairishoti.e.airinlettemperatureismore.Maximumpower:Engineconditionproducingmaximumpowerlikewhenvehicleisclimbinguphill,maximumheatrejectionisrequiredduringthiscondition.Tocompensateallthesefactorsradiatorcoresizerequiredmaybelarge.II.LITERATUREREVIEWC.Oliet,A.Oliva,J.Castro,C.D.studieddifferentfactorswhichinfluenceradiatorperformance.Itincludesairandcoolantflow,findensityandairinlettemperature.Itisobservedthatheattransferandperformanceofradiatorstronglyaffectedbyairandcoolantmassflowrate.Asairandcoolantflowincreasescoolingcapacityalsoincreases.Whenairinlettemperatureincreases,heattransferandthuscoolingcapacitydecreases.Smallerfinspacingandhigherlouverfinanglehavehigherheattransfer.Findensitycanbeincreasedtillitblockstheairflowandheattransferratedecreases.JPYadavandBharatRajSinghintheirstudiesalsopresentedparametricstudyonautomotiveradiator.Intheperformanceevaluation,aradiatorisinstalledintoatestsetup.Thevariousparametersincludingmassflowrateofcoolant,inletcoolanttemperature;etc.arevaried.Followingremarksareobservedduringstudy:Influenceofcoolantmassflowcoolingcapacityoftheradiatorhasdirectrelationwiththecoolantflowrate.Withanincreaseinthevalueofcoolingflowrate,thereiscorrespondingincreaseinthevalueoftheeffectivenessandcoolingcapacity.Influenceofcoolantinlettemperaturewiththeincreaseintheinlettemperatureofthecoolantthecoolingcapacityoftheradiatorincreases.MazenAl-Amayrehinhisstudy,testedthethermalconductivitiesofethyleneglycol+water,diethyleneglycol+waterandtriethyleneglycol+watermixtures,measuredattemperaturesrangingfrom25°Cto40°Candconcentrationsrangingfrom25wt.%glycolto75wt.%glycol.Increasingtheconcentrationofglycolleadstodecreaseofthermalconductivity.Increasingthetemperatureofmixtureresultedinslightincreaseinthermalconductivity.Thevarioustechniquesareusedtoenhancetheperformanceofautomotiveenginecoolingsystem.Itmaybeeitherconventionalormodernapproach.Conventionalapproachreliesonfin,tubeandfandesignoptimization.Moderntechniquesarebasedonnewtechnologieslikenano-technology,heatloadaveragingcapacityoractuatorbasedenginecoolingsystem.Thispaperreviewssomeoftheconventionalandmodernapproachesfocusingonradiatorperformanceenhancement.P.K.Trivedi,N.B.VasavaillustratedtheeffectofTubepitchforbestconfiguredradiatorforoptimumperformance.Heattransferincreasesasthesurfaceareaoftheradiatorassemblyisincreased.Thisleadstochangethegeometrybymodifyingthearrangementoftubesinautomobileradiatortoincreasethesurfaceareaforbetterheattransfer.ThemodificationinarrangementoftubesinradiatoriscarriedoutbystudyingtheeffectofpitchoftubebyCFDanalysisusingCFX.ResultsShowsthatasthepitchoftubeiseitherdecreasedorincreasedthanoptimumpitchoftubes,theheattransferratedecreases.PitambarGadhveandShambhuKumardescribeduseofdimplesurfacetoimproveforcedconvectionheattransfer.Heattransferenhancementisbasedonprincipleofscrubbingactionofcoolingfluidinsidethedimple.Surfacedimplespromoteturbulentmixinginflowandenhanceheattransfer.Anexperimentalsetuphasbeendesignedandfabricatedtostudyeffectofdimpledsurfaceonheattransferinrectangularduct.Resultscomparedwithflatsurfacetubeandfoundheattransferenhancementoverthelaterone.P.Gunnasegaran,N.H.Shuaib,andM.F.AbdulJalalintheirstudynumericalsimulationsonfluidflowandheattransfercharacteristicsoverlouveranglefinCompactHeatExchangersarereported.Acomputationaldomainfromthefluidinlettooutletissolved.Theimpactsofusingvariablelouverangles(+2°,+4°,?2°,?4°,anduniformangle20°)andlouveredfinwithvariablefinpitches(1mm,2mm,and4mm)onboththermalandhydraulicofCHEarepresented.TheNusseltnumberishigherforincreasedordecreasedlouveranglecomparedtouniformlouverangle.ThevariablelouveranglepatternsandlouverfinwithsmallerpitchappliedinCHEscouldeffectivelyenhancetheheattransferperformancewithmoderatedegradationofpressuredroppenaltycomparedtoplainfinsurfaceofCHE.Prof.D.K.Chavan,Prof.Dr.G.S.Tasgaonkarexplainedconventionalradiatorsizeisrectangularwhichisdifficultforcircularfantocoverwholesurfacearea.Itcreateslowervelocityzonesatcornersgivinglessheattransfer.Authorhasproposedtoeliminatecornersanddevelopcircularshaperadiatorwhichiscompact,moreefficientandleadstominimumpowerconsumptiontodriveafanandmaximumutilizationofairflow.Consideringlimitationsofconventionaltechniquestoimprovecoolingsystemperformancevariousnewtechnologiesareadopted.Researchisgoingontostabilizetheresults.K.Y.Leong,R.Saidur,S.N.Kazi,A.H.Mamundescribeduseofnanofluidbasedcoolantinenginecoolingsystemanditseffectoncoolingcapacity.Itisfoundthatnano-fluidhavinghigherthermalconductivitythanbasecoolantlike50%/50%waterandethyleneglycol.Itincreasesheattransfer.Soforsameheattransfer,radiatorcoreareacanbereducedcomparedtobaseone.Itfindsbettersolutiontominimizearea.Thermalperformanceofaradiatorusingnanofluidisincreasedwithincreaseinpumpingpowerrequiredcomparedtosameradiatorusingethyleneglycolascoolant.JohnVetroveccarriedworkonenginecoolingsystemwithheatloadaveragingcapacityusingpassiveheatloadaccumulator.Heatloadaccumulatorisphasechangematerialwhichstoresheatgeneratedduringpeakanddissipatesstoredheatduringreducedheatloadcondition.ThisisachievedbysacrificingphasechangeofPCMfromsolidtoliquidorviceversa.Thisleadstocompactheatexchangerforsameheatrejection.Alsoitreducesloadoncoolingsystem.Systemcanhandlehightransientloadsandpermitsfasterwarmupduringcoldenginestart.M.H.Salah,P.M.Frick,J.R.Wagner,D.M.Dawsondiscussedabouthydraulicactuatedcoolingsystem.Actuatorscanimprovetemperaturetrackingandreduceparasiticlosses.Actuatorbasedenginecoolingsystemusescontrollertocontrolcoolantpumpandradiatorfanoperatingconditions.Itprovidespowertosystemcomponentasperrequirement.Thusitregulatespowerconsumptionofsystemcomponentwithcoolingcapacity.Anonlinearbacksteppingrobustcontrollerisusedtoregulateenginecoolanttemperatureinhydraulicbasedthermalmanagementsystem.Proposedcontrollermaintainedthecoolanttemperaturetoitssetpointwithsystemimprovement.Useofthissystemoffersgreaterpowerdensitywithcompactinnature.III.FUTURESCOPEEnginecoolingsystemcancontributeinsomeoftheengineaspectslikereductioninfuelconsumptionthusminimizingexhaustandfuelemission.Thiscanbeachievedbykeepingengineatoptimumthermaloperatingconditions.Alsothermalloadonengine,enginecomponents,lubricatingfluidcanbereduced.Effectiveenginecoolingsystemcanhelptoshortenenginewarmupperiodduringcoldstartandheatlossrecoverytoimprovedrivingcomfort.Reductioninweightandrequiredspacetofitsystemonavehicleisthemostchallengingtaskindevelopingcoolingsystem.Alsoeffortstobetakentoimplementuseofemergingtechnologieslikenano-technologyandtostabilizetheresultsofthesesystems.Inshort,futurechallengesincludedevelopingmorecompact,lightweight,improvedperformanceandeconomicalenginecoolingsystem.IV.PROPOSEDWORKTheproposedworkisconcernedwithdevelopingexcelsheettocalculateheatrejection.Fewinputparameterswillgiveexactidearegardingheatrejection.Sheetwillhelptoestimateeffectofvaryingtubeandfindensity,coolantflowrateetc.onheatrejection.Theoreticalcalculationofradiatorcoresizeandheatrejectionforagivenengineinputs.Validationofcoresizebysimulationsoftwareandcomparingtheoreticalheatrejectionwithsimulationresults.Optimizingcoresizeasperheatrejectionrequirement.3Dmodelingofradiatorcomponentsheader,tubes,finsandtanks.Finiteelementanalysisofradiatortotestitsrobustnessforthermalandpressureloads.Prototypedevelopmenttovalidatetheradiatorperformance.[1]C.Oliet,A.Oliva,J.Castro,C.D.Pe′rez-Segarra,―Parametricstudiesonautomotiveradiators‖,AppliedThermalEngineering,27,2007[2]JPYadavandBharatRajSingh,―StudyonPerformanceEvaluationofAutomotiveRadiator‖,S-JPSET:ISSN:2229-7111,Vol.2,Issue2,2011[3]MazenAl-Amayreh,―ExperimentalStudyofThermalConductivityofEthyleneGlycolWaterMixtures‖,EuropeanJournalofScientificResearch,ISSN1450-216XVol.44No.2,2011[4]P.K.Trivedi,N.B.Vasava,―EffectofVariationinPitchofTubeonHeatTransferRateinAutomobileRadiatorbyCFDAnalysis‖,InternationalJournalofEngineeringandAdvancedTechnology(IJEAT)ISSN:2249–8958,Volume-1,Issue-6,2012[5]PitambarGadhave,ShambhuKumar,―EnhancementofforcedConvectionHeatTransferoverDimpleSurface–Review‖,InternationalMultidisciplinarye–Journal,2012[6]P.Gunnasegaran,N.H.Shuaib,andM.F.AbdulJalal.―TheEffectofGeometricalParametersonHeatTransferCharacteristicsofCompactHeatExchangerwithLouveredFins‖,ISRNThermodynamics,Volume2012[7]Prof.D.K.Chavan,Prof.Dr.G.S.Tasgaonkar,―ThermalOptimizationofFanassistedHeatExchanger(Radiator)byDesignImprovements‖,InternationalJournalofModernEngineeringResearch(IJMER),Vol.1,Issue1,2011[8]K.Y.Leong,R.Saidur,S.N.Kazi,A.H.Mamun,―Performanceinvestigationofanautomotivecarradiatoroperatedwithnanofluidbasedcoolants(nanofluidasacoolantinaradiator)”,AppliedThermalEngineering,30,2010[9]JohnVetrovec,―EngineCoolingSystemwithaHeatLoadAveragingCapability‖,SAEInternational,2008[10]M.H.Salah,P.M.Frick,J.R.Wagner,D.M.Dawson,―Hydraulicactuatedautomotivecoolingsystems—Nonlinearcontrolandtest‖,ControlEngineeringPractice,17,2009汽車散熱器性能摘要：汽車發(fā)動機冷卻系統(tǒng)是負責(zé)帶走發(fā)動機運轉(zhuǎn)過程中產(chǎn)生的多余的熱量。它調(diào)節(jié)發(fā)動機的表面溫度，來使發(fā)動機達到的最佳效率。最近隨著發(fā)動機動力的發(fā)展迫使發(fā)動機冷卻系統(tǒng)提出新的策略來改進其性能效率。也可以通過減少燃料消耗以及控制發(fā)動機排放，減輕環(huán)境污染。本文闡述了參數(shù)影響散熱器性能以及評論的一些傳統(tǒng)和現(xiàn)代的方法來提高散熱器的性能。指數(shù)—發(fā)動機冷卻系統(tǒng)、性能、散熱器一、介紹汽車發(fā)動機冷卻系統(tǒng)負責(zé)發(fā)動機運轉(zhuǎn)過程中產(chǎn)生的余熱。它調(diào)節(jié)發(fā)動機表面溫度對發(fā)動機最佳效率。大多數(shù)汽車發(fā)動機冷卻系統(tǒng)由散熱器、水泵、冷卻風(fēng)扇、壓力上限和恒溫器。散熱器是系統(tǒng)的主要組件。散熱器是一個熱交換器,冷卻液通過它帶走發(fā)動機中的熱量。熱量從熱冷卻劑轉(zhuǎn)移到外面的空氣。散熱器總成由三個主要部分組成核心,進口箱和出口。核心有兩套,一套管子和風(fēng)扇。冷卻劑流過管子和風(fēng)扇之間的空氣流。熱冷卻劑將熱量傳遞至風(fēng)扇。外部空氣通過風(fēng)扇之間氣流帶走體內(nèi)的熱量。發(fā)動機冷卻系統(tǒng)的性能的影響因素,比如空氣和冷卻劑質(zhì)量以及流率,進氣溫度,冷卻液,風(fēng)扇類型、翅片間距、管式和管間距等。在設(shè)計冷卻系統(tǒng)三個最基本的條件是基于以上參數(shù)。高海拔:在高空,空氣密度低,因此會影響空氣質(zhì)量流率。夏天條件:在夏季周圍空氣是熱即進氣溫度。最大力量:發(fā)動機最大功率的生產(chǎn)條件如車輛爬上坡時,最大熱扭矩在這個條件是必需的。考慮所有這些因素，所需要的散熱器核心尺寸可能很大。二、文獻綜述C.Oliet,A.Oliva,J.Castro,C.D研究不同因素影響散熱器性能。它包括空氣和冷卻液流,風(fēng)扇和空氣入口溫度。這是觀察到散熱器的傳熱和性能受到空氣和冷卻劑質(zhì)量流率的影響很大。隨著空氣和冷卻液流增加，冷卻能力也增加。當(dāng)空氣進口溫度的增加,傳熱,從而冷卻能力降低。小翅片間距和更高的百葉窗式翅片角有較高的傳熱。風(fēng)扇密度可以增加直到空氣流動和傳熱速率降低。JPYadav和BharatRajSingh在他們的研究也提出了參數(shù)研究汽車散熱器。在散熱器的安裝測試中得到散熱性能參數(shù)。冷卻劑的各種參數(shù)包括質(zhì)量流率,進氣冷卻劑溫度;等多種多樣。以下評論期間觀察研究:冷卻液質(zhì)量流量的冷卻能力的影響散熱器與冷卻劑流量有直接關(guān)系。與冷卻流量的價值,有相應(yīng)增加的效果和冷卻能力的價值。冷卻液入口溫度的影響提高入口溫度的冷卻液散熱器的冷卻能力增加。MazenAl-Amayreh在他的研究中發(fā)現(xiàn),經(jīng)過測試乙二醇+水的熱導(dǎo)率,二甘醇+水和三甘醇+水混合物,測量溫度從25°C到40°C和濃度范圍從25wt%乙二醇75wt%乙二醇。醇濃度的增加會導(dǎo)致熱導(dǎo)率降低。增加混合物的溫度能夠少量的增加熱導(dǎo)率。傳統(tǒng)的或現(xiàn)代的方法都能夠用來提高汽車發(fā)動機冷卻系統(tǒng)的性能。傳統(tǒng)的方法依賴于風(fēng)扇,管和風(fēng)扇設(shè)計優(yōu)化?，F(xiàn)代技術(shù)是基于新技術(shù)如納米技術(shù)、熱負荷平均容量或發(fā)動機冷卻系統(tǒng)執(zhí)行機構(gòu)的建立。本文綜述的一些傳統(tǒng)和現(xiàn)代方法主要用來增強散熱器性能。P.K.Trivedi,N.B.Vasava認為管間距的最佳配置能夠讓散熱器發(fā)揮最高性能。傳熱表面積增加會改變散熱器裝配。這導(dǎo)致改變管子的幾何形狀或者通過修改汽車散熱器的排布可以使表面積增加更好的傳熱。協(xié)議的修改管散熱器是由學(xué)習(xí)管距的影響通過CFD分析使用它。結(jié)果表明,管間距的減少或增加比最佳距管,傳熱率降低。PitambarGadhve和ShambhuKumar稱使用凹槽提高強制對流傳熱表面。強化傳熱技術(shù)基于冷卻液與凹槽的摩擦。表面凹槽促進流動和湍流混合增強傳熱。研究實驗設(shè)置了帶凹槽的和普通矩形的散熱性能對比。實驗結(jié)果與平面管對比之后,發(fā)現(xiàn)帶有凹槽的傳熱增強。p.Gunnasegaran:h.Shuaib,m·f和M.F.AbdulJalal在他們的研究中說道在流體流動和傳熱特性數(shù)值模擬百葉窗角度緊湊熱交換器。從流體計算域入口出口是解決。使用變量的影響百葉窗角度(+2°,+4°,-2°,-4°,和統(tǒng)一的角度20°)變量和裝有百葉窗板的鰭鰭球(1毫米,2毫米和4毫米)的熱力和水力切。增加或減少的努塞爾特數(shù)較高百葉窗角度而統(tǒng)一的百葉窗角度。變量模式和百葉窗式翅片百葉窗角度較小;該應(yīng)用能有效地提高傳熱性能與中度退化的壓降比平翅片表面切處罰。Prof.D.K.Chavan,Prof.Dr.G.S.博士解釋說傳統(tǒng)散熱器大小循環(huán)風(fēng)扇難以覆蓋矩形整個表面。它創(chuàng)造了低速度區(qū)角落給更少的熱量轉(zhuǎn)移。作者提出了消除角落和發(fā)展更為緊湊的圓形散熱器,來提高效率,以便達到最小功耗驅(qū)動風(fēng)扇和最大利用氣流?？紤]傳統(tǒng)技術(shù)的局限性,提高冷卻系統(tǒng)性能采用各種新技術(shù)。研究逐漸變成現(xiàn)實。K.Y.Leong,R.Saidur,S.N.Kazi,A.H.Mamun描述使用基于nanofluid冷卻液在發(fā)動機冷卻系統(tǒng)及其對冷卻能力的影響。發(fā)現(xiàn)thatnano-fluid有更高的熱導(dǎo)率比基礎(chǔ)冷卻劑50%/50%水和乙二醇。它具有更好的導(dǎo)熱性。對于相同的傳熱,散熱器核心區(qū)域相比可以減少基地之一。找到更好的解決方案來減少區(qū)域。使用nanofluid散熱器的熱性能相比相同泵功率使用乙二醇作為冷卻劑的散熱器要好很多。JohnVetrovec使用熱負荷蓄電池發(fā)動機冷卻系統(tǒng)的被動進行熱負荷平