壁湍流非定常結(jié)構(gòu)復渦粘模式及人工擾動作用的實驗研究.pdf

1、天津大學碩士學位論文壁湍流非定常結(jié)構(gòu)復渦粘模式及人工擾動作用的實驗研究姓名：王昕申請學位級別：碩士專業(yè)：流體力學指導教師：舒瑋姜楠2001.1.1ExperimentalResearchonComplexEddyViscosityModelofUnsteadyStructureandTheEfiectofArtifieialDisturbanceinWallTurbulenceAbstraetInthispaperartificiald

2、isturbanceisintroducedtoturbulentboundarylayerandhotfilmanemometerisemployedtomemeasurementindownstreamfieldInthiswaytheforillofeddyviscositytoemcientineddyviscositymodelingofwallturbulenceiSstudied，whereaperiodiclargesc

3、alestructureexists；Inaddition，theeffectofdisturbancetothedownstreamfieldiSanalyzedwimdi舵rentmethodsAselfdesignedmechanicalvibrationdeviceiSusedtogenerateperiodicaldisturbanceinawaterchannel，atthesametime，anXstylehotfilmp

4、robeiSemployedtomeasureindownstreamareaInthispaperaccordingtothemodelingofcoherentinouterfieldofboundarylayeraphase—averagemethodiSperformedtothefluctuatingsignalintermofafiducialfrequencywhichisthefrequencyoftheperiodic

5、allarge—scalestructureinfluctuatingvelocitycapturingbypowerspectrumanalysis，thenitisstudiedofthefornlofeddyviscosityinturbulentboundarylayerwhereaperiodiclargescalestructureexistbycomparingthephasevalueofthelargescalestr

6、ainrateandReynoldsstressaccordingtotheperiodicdisturbanceItiSfoundthat，aphasevarietyexistsbetweenthelargescalestrainrateandReynoldsstressaccordingtotheperiodicdisturbalice，whichiSallunconsideredimportantfactorinthemostof

7、modelingthepriesofturbulenceinducedtoeddyviscosityForthedisturbanceintroducedtoouterfieldofboundarylayer，theattenuationofperiodicdisturbancesalongnormaldirectioninturbulentboundarylayerisstudiedbyspectrumanalysis，inthisp

8、aperitisfoundthatthehigherfrequencydisturbanceattenuatesoonerthanthelowerones；moreoverallofthedisturbancewithdifierentfrequencyCallnotaffecttheflowofthemain—flowbycrossingtheedgeofboundarylayerAtlast，weputemphasisontheef

9、fectofdisturbancetothevariousscalestructureinturbulenceFirst，apreliminaryresultiSacquiredontheinfluenceofdisturbancetoturbulentfluctuatebypowerspectrumandselfcorrelationanalysisItshowstllatthestrongesteffecttothestructur

10、eofturbulencecomingfromlOhzdisturbanceSecond，thechangeofenergyofvariousscalestructureinturbulencearoundaddingdisturbanceisacquiredbyusingwaveletanalysisFortheveracityofwaveletanalysisonfluctuatingvelocityaddeddisturbance

11、，itisalsoinvestigatedthattheconnectionbetweentherealfrequencyvalueandthescaleofwaveletfunction；besides，theenergyleakageexistedintheresultofwaveletanalysistotheperiodicalsignaliSanalyzedandthemethodtoavoiditisfoundFinally