资源描述：
《fluid turbulence》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、FluidturbulenceKatepalliR.SreenivasanMasonLaboratory,YaleUniversity,NewHaven,Connecticut06520-8286Theswirlingmotionof¯uidsthatoccursirregularlyinspaceandtimeiscalledturbulence.However,thisrandomness,apparentfromacasualobservation,isnotwithoutsomeorder.Turbulent¯ows
2、areasabundantinnatureaslifeitself,andarepervasiveintechnology.Theyareaparadigmforspatiallyextendednonlineardissipativesystemsinwhichmanylengthscalesareexcitedsimultaneouslyandcoupledstrongly.Thephenomenonhasbeenstudiedextensivelyinengineeringandindiverse®eldssuchas
3、astrophysics,oceanography,andmeteorology.Afewaspectsofturbulenceresearchinthiscenturyarebrie¯yreviewed,andapartialassessmentismadeofthepresentdirections.[S0034-6861(99)03202-X]I.INTRODUCTORYREMARKSUntilthe1960s,turbulencewastheparadigmsysteminwhichtheexcitationofma
4、nylengthscaleswasrecog-Thefascinatingcomplexityofturbulencehasattractednizedasimportant.Thepowerfulnotionsofscalingandtheattentionofnaturalists,philosophers,andpoetsalikeuniversality,whichmaturedwhenrenormalizationforcenturies,andubiquitousallusionshavebeenmadegrou
5、ptheorywasappliedtocriticalphenomena,hadal-totheturbulenceofagitatedmindsanddisturbedreadymanifestedinturbulenceacoupleofdecadesear-dreams,offuriousriversandstormyseas.Perhapsthelier.Turbulenceandcriticalphenomenonsharethefea-earliestsketchesofturbulent¯ows,capturi
6、ngdetailswithsomedegreeofrealism,arethoseofLeonardodaturethatacontinuousrangeofscalesisexcitedinboth;Vinci.Aseriousscienti®cstudyhasbeeninprogressforhowever,theyaredifferentinthatthe¯uctuationsinmorethanahundredyears,buttheproblemhasnotyetturbulencearestrongandther
7、eexistsnosmallparam-yieldedtoourefforts.AsLiepmann(1979)haspointedeter.Thus,turbulenceisaparadigminnon-equilibriumout,theoutlook,optimism,andprogresshavewaxedstatisticalphysics,inwhich¯uctuationsandmacroscopicandwanedovertime.space-timestructurecoexist.Itisanexampl
8、elikenoFewwoulddisputetheimportanceofturbulence.otherofspatiallyextendeddissipativesystems.Withoutit,themixingofairandfuelinanautomobileAnexcelle
