简介：ByanalyzingturbulencedatameasuredattwositesincoastalregionsofHangzhoubay,itisdiscoveredthat:(1)TheturbulentintensityI_kisinverselyproportionaltothewindspeedatlowerspeed.Whileathigherwindspeed,itkeepsbasicallytobeconstant.(2)Undertheunstableconditionsinthevicinityofseashore,thedimensionlessstandarddeviationsofwindspeedσ_k/U(?)areconstantsbasically,whileintheinland,theycanbedescribedbytheexpressionssimilartoPanofsky(1977)modelsbutwithdifferentconstants.Underthestableconditions,theyareconstantswhenZ/L<0.2andproportionalto1/3powerofZ/LforlargerZ/L.(3)Nearthecoast,thevariationofU(?)/UwithZ/LfollowsBusinger(1971)modelU(?)/U=k/(?)(Z/L)verywellnotonlyunderstablebutalsounderunstablecondition.Inland,itiscoincidentverywellmerelyunderthecondition-1.0≤Z/L≤0.3.Outthisrange,thedeviationislarge.(4)ThedispersionparameterscanbedescribedintheformrecommendedbyDraxler(1976)butwithdifferentconstants.Undertheunstablecondition,theycanalsobeexpressedasBriggs(1985)modelwithdifferentconstants.

简介：“2005TrainingCourseonSmallHydropowerforAsia-PacificCountries”isspecificallyfordevelopingcountriesunderthelistofaidtoforeigncountriesbytheChinesegovernment.EntrustedbytheMinistryofCommerce,HangzhouRegionalCenterforSmallHydroPower(HRC)willundertakethemission.

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简介：Themeasurementaccuracyofanultrasonicheatmeterdependsontherelationshipoftheprofile-linearaveragevelocity.Therearevariousmethodsforthecalculationofthelaminarandturbulenceflowregions,butfewmethodsforthetransitionregion.Atpresent,thetraditionalmethodtodealwiththetransitionregionistoadopttherelationshipfortheturbulentflowregion.Inthisarticle,asimplifiedmodelofthepipeisusedtostudythecharacteristicsofthetransitionflowwithspecificReynoldsnumber.Thek-εmodelandtheLargeEddySimulation(LES)modelare,respectively,usedtocalculatetheflowfieldofthetransitionregion,andacomparisonwiththeexperimentresultsshowsthattheLESmodelismoreeffectivethanthek-εmodel,itisalsoshownthattherewillbealargeerroriftherelationshipbasedontheturbulenceflowisusedtocalculatetheprofile-linearaveragevelocityrelationshipofthetransitionflow.Theprofile-linearaveragevelocityfortheReynoldsnumberrangingfrom5300to10000arecalculated,andtherelationshipcurveisobtained.Theresultsofthisarticlecanbeusedtoimprovethemeasurementaccuracyofultrasonicheatmeterandprovideatheoreticalbasisfortheresearchofthewholetransitionflow.