野外風沙躍移運動的觀測實驗與數(shù)值模擬.pdf

1、蘭州大學博士學位論文野外風沙躍移運動的觀測實驗與數(shù)值模擬姓名：史鋒申請學位級別：博士專業(yè)：力學固體力學指導教師：黃寧20100501蘭州大學博士學位論文野外風沙躍移運動的觀測實驗與數(shù)值模擬ABSTRACTStudiesoferosionsaltationarecurrentlyconcentratingonwindtunnelexperiments，theoreticalanalysesandnumericalsimulationsun

2、deridealaswell硒controllableconditions，suchasundertimeinvariantwindspeedandflatsandbedWhereaStheresearchesofeffectsoffluctuationscharacteristicsofwindvelocityandthecomplexmicrotopographyinrealdesertonsandsaltationappearto

3、bemuchfeweralthoughthesetopicshaveobtainedincreasingrecognitionofimportanceinrecentdecadesThisdissertationpresentssomebasicfieldexperimentsandtheoreticalmodelingandcomputationalsimulmionforerosionsaltation，andthemainachi

4、evementsaremadeinthefollowingaspects：1BasedoncooperationwithWindErosionandWaterconservationResearchUnitofUSAgricultureDepartment，weinstalledanddebuggedasystemwithaformerstationmasterofBigSpringFieldStation，asoilscientist

5、，Donald(Bill)FryrearwhichWasdesignedtosynchronouslymeasurephysicalquantities，such嬲fluctuatingnearsurfacewindvelocitysandtransportintensitytemperatureandhumiditywith1HzfrequencyattwopointsonthebarchanduneinMinqinarea，whic

6、hislocatedbetweenedgesoftheBadainJaranDesertandtheTenggerDesert2ThemeasuredwindspeedandsaltationintensityareusedtocalculatethresholdwindspeedinlocalenvironmentalconditionsTheresultsshowthatthethresholdwindspeedvariesinco

7、mplexways，asaresultofthevariationoflocalenvironmentalconditionsduringtheduststormThroughanalyzingobservationaldataitisfoundthatthecorrelationcoefficientbetweenhorizontalwindvelocityandsandsaltationintensitylogarithmicall

8、yincreaSeswiththeincrementoftimestepwhenitislessthan40secondsandthenitgraduallytendstostable3Usinganumericalmodelofsandsaltation，weanalyzedthefieldsandfluxesunderthefluctuatingwindspeed，andthenumericalresultsarefairlycoi