Single-phase heat transfer in micro-fin tubes 英文文献资料

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1、InrJ.HrorMos.5Transfer.Vol40.NoIX,pp.43454357.1997Q1997ElsevierSaenceLtd.AllrightsreservedPergamonPmtedinGreatRrltain0017-9310’9751700+0.00PI1:soo17-9310(97)00078-1Single-phaseheattransferinmicro-fintubesL.J.BROGNAUX,RALPHL.WEBBtandLOUAYM.CHAMRADepartmentofMechanicalEngineering,ThePennsylvaniaState

2、University,UniversityPark.PA16802,U.S.A.andBAIKYOUNGCHUNGLGElectronicsInc,Changwon,Korea(Received31July1996andinJinal,form20February1997)Abstract-Micro-fintubesaretypicallyusedfortube-sidecondensationandevaporation.Thisstudyprovidesheattransferandfrictioncharacteristicsforsingle-phaseflowinsingle-g

3、roovedandcross-groovedmicro-fintubes.Dataweretakenforturbulentflowwith0.70

4、ryonthePrandtlnumberdependence.Theheattransfercharacteristicsweredeterminedasfunctionsofthe‘roughnessReynoldsnumber’usingtheheat-momentumtransferanalogyproposedbyDippreyandSabersky.TheobservedPrandtlnumberexponent(n=0.564.57)agreeswellwithreportedworkondifferenttwo-dimensionalroughnessgeometries.Th

5、epresentsingle-phasecorrelationsshouldbeusefulindevelopingcorrelationstopredicttheheattransfercoefficientforforcedconvectioncondensationinsingle-groovedandcross-groovedmicro-fintubes.01996ElsevierScienceLtd.INTRODUCTIONHeattransferenhancementhasbeenanimportantfactorinobtainingenergyefficiencyimprov

6、ementsinrefrigerationandair-conditioningapplications.Micro-fintubesareroutinelyusedtoprovideenhance-mentfortube-siderefrigerantcondensationandevap-oration.Thistube,illustratedinFig.l(a),hastri-angularcross-sectionfins0.24.35mmhighathelixanglesbetween8and30”(measuredfromthetubecenterline).Althoughth

7、etubeisroutinelyused,rationallybasedpredictivemethodsarenotavailable.Correlationsforcondensationandevaporationinsmoothtubesaretypicallyrelatedtothesingle-phaseheattransferperformance.Hence,single-phasechara