ON THE PDF MODELS FOR ATMOSPHERIC DIFFUSION IN BOUNDARY LAYER

(整期优先)网络出版时间:1999-04-14
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Inthispaper,takingitsturbulentexchangecoefficientasafunctionoftheLagrangiantimescaleandstandardvarianceoftheturbulenceinatmosphere,theatmosphericdispersionPDFmodelsareobtainedonthebasisofatmosphericdiffusionK-theory.Inthemodelthestatisticsofwindspeedaredirectlyusedasitsparametersinsteadofclassicdispersionparameters.Thebi-GaussianPDFisderivedinconvectiveboundarylayer(CBL),fromthestatisticsofverticalvelocityinbothofthedowndraftandupdraftregionsthatareinvestigatedtheoreticallyintheotherpartofthispaper.GivingthedrivenparametersoftheCBL(includingtheconvectivevelocityscalew*andthemixingdepthh_i)andthetime-averagedwindspeedatreleaselevel,thePDFmodelisabletosimulatethedistributionofconcentrationreleasedatanylevelsintheCBL.ThePDF’ssimulationsarefairlyconsistentwiththemeasurementsinCONDORSexperimentortheresultsbroughtoutbysomenumericalsimulations.