Influence of artificial ecological floating beds on river hydraulic characteristics

(整期优先)网络出版时间:2014-03-13
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Theartificialecologicalfloatingbediswidelyusedinriversandlakestorepairandpurifypollutedwater.However,thewaterflowpatternandthewaterleveldistributionaresignificantlychangedbythefloatingbeds,andtheinfluenceonthewaterflowisdifferentfromthatofaquaticplants.Inthispaper,basedonthecontinuousporousmediamodel,amoveabletwo-layercombinationmodelisbuilttodescribethefloatingbed.Theinfluencesofthefloatingbedsonthewaterflowcharacteristicsarestudiedbynumericalsimulationsandexperimentsusinganexperimentalwaterchannel.Thevariationsofthewaterleveldistributionarediscussedunderconditionsofdifferentflowvelocities(v=0.1m/s,0.2m/s,0.30m/s,0.4m/s),floatingbedcoveragerates(20%,40%,60%)andarrangementpositionsawayfromthechannelwall(D=0m,0.1m,0.2m).Theresultsindicatethattheflowvelocityincreasesunderthefloatingbeds,andthewaterlevelrisessignificantlyunderhighflowvelocityconditionsintheupstreamregionandthefloatingbedregion.Inaddition,theaveragerisingwaterlevelvalue(ARWLV)increasessignificantlywiththeincreaseofthefloatingbedcoveragerate,andthearrangementpositionoffloatingbedsintherivercanalsogreatlyinfluencethewaterleveldistributionunderahigh-flowvelocitycondition(v?0.2m/s).