摘要在本课题的研究中，应用水动力学及污染物传输耦合的数值计算的数值模型，通过建立基于二维和三维不可压缩流体Navier-Stokes方程和湍流k-ε模型的重力流及污染物数值计算的数学模型[1]来模拟河道的弯曲度对不可分解污染物在弯曲河道中的分布的影响，这对处理河道中的突发性污染事件的科学决策有一定的参考作用。由二维和三维的模拟结果可知，河道弯曲度对污染物在河道内的分布主要取决于流速和重力作用的影响。流速的改变主要出现在河道的弯曲处，这时会在弯道处出现回流区和死水区，它会阻碍密度较大的污染物的流动，使得这一侧污染物浓度较大。而在污染物随着水流往下游流动的过程中，重力作用也会显现出来。由于污染物的密度比水要大，这使得污染物在流动的过程中往河底沉降下来，继而在河道底部形成以河道中心线为对称轴的坍塌回聚式震荡的扩散过程。关键字:河流污染物环境污染数值模拟FluentGambitAbstractInthisissueofthestudy,theapplicationofhydrodynamicsandcontaminanttransportnumericalcouplednumericalmodel,Throughtheestablishmentoftwo-dimensionalandthree-dimensionalincompressibleNavier-Stokesequationsandfluidturbulencek-εmodelofgravityflowandpollutantnumericalcalculationofthemathematicalmodel[1]tosimulatethedistributioneffectionofcurvatureofrivertoindecomposablepollutionintheriverbend,whichhavesomereferencetodealwiththesuddenriverpollutionincidentsinthescientificdecision-making.Bytheresultsoftwo-dimensionalandthree-dimensionalsimulation,weknowtherivercurvaturetothedistributionofpollutantsintheriverchannelsdependsonthevelocityandgravity.Velocitychangewasseenintheriverbend,thenthebackriverareaanddeadzoneareawillappearinthecorners,itwillimpedetheflowofpollutantsinhighdensity,makingthissidewithlargeconcentrationofpollutants.Asthepollutantsflowdownstreamwiththewater,theinfluentofgravitywillappear.Asthecontaminantsdensityislargerthanwater,whichmakesthepollutantsintheflowsettledowntotheriverbottom,andthenintheriverbottomtoformachannelforthesymmetryaxisofthecollapseofthecenterlineofpoly-typeshockreturntothediffusionprocess.Keywords：Rivers，Pollutants，EnvironmentPollution，Numericalmodel，Fluent，Gambit目录目录................................................21．引言.............................................41.1课题研究背景.............................................................................................................41.2国内外水污染状况.......................................................................................................41.3国内外水质模型研究现状............................................................................................61.4弯曲河道污染物分布数值模拟的任务和内容............................................................71.5弯曲河道污染物数分布值模拟的意义......................................................................82．数值计算模型...................................................................................................................82.1水质模型的介绍...........................................................................................................82.2.数学模型发展历史.....................................................................................................82.3三维模拟污染物扩散控制方程....................................................................................92.4模拟边界条件.............................................................................................................122.5数值计算方法..........................................
