资源描述：
《Experimental study on compressible flow in microtubes.pdf》由会员上传分享，免费在线阅读，更多相关内容在学术论文-天天文库。
1、InternationalJournalofHeatandFluidFlow28(2007)28–36www.elsevier.com/locate/ijhffExperimentalstudyoncompressibleflowinmicrotubesa,*baaaG.P.Celata,M.Cumo,S.J.McPhail,L.Tesfagabir,G.ZummoaENEA,InstituteofThermalFluidDynamics,ViaAnguillarese301,00060S.M.Galeria,Rome,ItalybUnivers
2、ityofRomeLaSapienza,CorsoVittorioEmanueleII,244Rome,ItalyAccepted27April2006Availableonline9August2006AbstractGasflowinmicrochannelshaspracticaladvantagescomparedtotheuseofliquids,inthatsystemrequirementsaregenerallyofalighterandlessfragilenature.However,theaspectofcompressi
3、bilitybecomesanissuetotakeintoaccount.Duetothehighfrictionalheadlossinmicroscopicchannels,gasdensitycanvaryuptoanorderofmagnitudebetweeninletandoutlet,andcorrespondinglyaltertheshapeandmagnitudeofthevelocityprofile.Inthisarticlethepossibleeffectsofthismicroscalephenomenonarei
4、nvestigated.Tothiseffect,anexperimentalprocedurefordeterminingalocalfrictionfactorisimplemented,andcomparedwithalinearizedglobalfrictionfactor.Furthermore,aquantitativecomparisonbetweenthelinearized(incompressible)approximationandtwo‘‘quasi-compressible’’correlationsforthefr
5、ictionfactorisincluded.TheresultsshowaremarkablyaccuratepredictionofthefrictionfactorbythereferencecurveofHagen-Poiseuille,f=64/Re,regard-ingtheglobalaswellasthelocalapproximations,andaverycloseagreementbetweentheincompressibleandquasi-compressiblecor-relations.Thisgoestoin
6、dicatethattheafore-mentionedeffectsofdensity-change-inducedaccelerationareextremelylimitedonapracticalscale,andthatanincompressiblecharacterizationisvalidwithinthestudiedconditionsofflow.Therangeofvalidityissyn-thesizedinalimitingvalueofthepressureratioatagivenexperimentalunc
7、ertainty.Ó2006ElsevierInc.Allrightsreserved.Keywords:Gasflow;Microtube;Experimental;Frictionfactor;Fusedsilicapipe;Poiseuillenumber1.Introductionpublishedresultstobemoreorderly,andtoconvergetowardstheclassicaltheoriesmorethanwasoriginallyTheminiaturizationofmanyappliancesinb
8、iomedic,expected.chemicalandcomputertechnologyhasbroughtwithitConditionsarefairlye
