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95 个结果
  • 简介:Lid-drivenmixedconvectionhasbeengivenimmenseimportanceduetoitswiderangeofapplications.AT-shapedcavityisintroducedandpertinentparameterscontrollingmixedconvectionphenomenonareanalyzedinthispaper.Water-Al2O3nanofluidisconsideredinsidethecavitytoaugmentheattransferrate.Galerkinweightedresidualmethodoffiniteelementanalysisisappliedforthenumericalsimulations.Numericalsolutionisobtainedfordifferentsolidvolumefractionsofnanofluid(?=0-0.15),Grashofnumbers(Gr=0.1?5000)andReynoldsnumbers(Re=0.31?1000)inlaminarflowregime.Specialattentionisgivenontheanalysisofflowatthepuremixedconvectionregime.ItisfoundthatGrashof,ReynoldsandRichardsonnumbersalongwithsolidvolumefractionofnanofluidhavesignificanteffectonheattransfercharacteristicsinsidethecavity.ResultsarepresentedusingstreamlineandisothermcontoursalongwithrelatedvariationofaverageNusseltnumbersoftheheatedwallandaveragefluidtemperatureinsidethecavity.

  • 标签: 纳米流体 雷诺兹数 流体混合 固相体积分数 平均努塞尔数 流数
  • 简介:氮素通过干湿沉降、地表径流、农业灌溉等途径进入湿地中,导致湿地N2O的产生和排放发生变化,而N2O是一种温室气体,具有较高的温室效应潜力,会对环境造成严重影响。本研究模拟白洋淀芦苇湿地,构建人工模拟湿地系统进行外加氮素试验,用静态暗箱-气相色谱法进行N2O的通量观测,研究外源氮素输入对湿地N2O排放通量的影响。结果表明,外源氮素形态的不同不仅影响湿地系统中环境因子的改变,还会影响氮素进入湿地系统后的迁移转化。硝态氮是湿地N2O产生和排放的主要影响因子,芦苇湿地系统中氮素的反硝化作用强于无植被湿地系统,N2O的排放主要发生在反硝化过程中。

  • 标签: 外源氮素 湿地 N2O
  • 简介:本文结合水利规划工作,对应用新型数据处理软件LotusI-2-3在水文水利计算数据处理方面进行一点探索。

  • 标签: 水利计算 水利规划 水文 应用
  • 简介:西安市黑河引水工程位于我省周至县境内,主要为西安市供水,兼作发电,黑河水库库容2亿m^3,坝体为土石坝,最大坝高135m。该枢纽设引水洞、泄洪洞、溢洪洞三条隧洞。泄洪洞进口高程545m、最大泄量2540m^3/s。当库水位达到汛限水位591m时,泄洪洞工作弧门开始泄洪,当库水位达到保坝水位599.5m时,泄洪洞工作弧门、溢洪洞工作弧门联合泄洪。库水位每年均有低于进口高程545m的运行工况,泄洪洞工作弧门实际运行水头为0~50m,有局部开启要求、运行工况较复杂。泄洪洞工作弧门设计参数如表1。

  • 标签: 泄洪洞 工作弧门 库水位 引水工程 溢洪洞 泄量
  • 简介:Inthispaper,perturbationmethodandFourier-cosine-expansionmethodareusedtosolvea3-DnonlinearproblemofasupercavitatingflowinaninclinedfieldofgravityatlargeFroudenumbers.Byexpandingthevelocitypotentialintoapowerseriesofasmallparameter,theoriginal3-Dnonlinearproblemisreducedtoanumberof2-Dones.Thesolutionsofthefirstthreeordersarederivedindetailandexpressedintermsofthecompleteellipticintegralsofthefirstandsecondkinds.Thentheboundaryintegralequationmethodisappliedtogetthenumericalsolutionsforeachorder.Computationalresultsareprovidedforsupercavitatingflowspastconesundervariousflowconditions.

  • 标签: supercavitating flow NONLINEAR free surface PERTURBATION
  • 简介:Inthepresenceofbottomwater,adropinthereservoirpressureduetofluidproductioncausestheaquiferwatertoexpandandtoflowintothereservoir.Therefore,hydrocarbonproductionfromawellislimitedbythecriticalflowrate.Themainpurposeofthisstudyistoinvestigatethebreakthroughtimeandthecriticalratebyusinganovel3-Dhorizontalwellmodel.Basedonthehypothesisthatthehorizontalwellislocatedinanypositionofacircularreservoirwithno-flowboundaryonthetopofthereservoirandconstantpressureboundaryatthebottom,thehorizontalwellhasbeenregardedasaninfiniteconductivitylinesinkandthena3-Dsteady-stateflowmodelofthehorizontalwellissetup.ApointsinkpressuresolutioncanbeobtainedwiththeFouriertransform.Theresultofthepressuredistributionoftheuniformfluxhorizontalwellcanbepresentedbymeansoftheprincipleofsuperposition.Accordingtothestablewatercrestingtheory,thisstudyconfirmsthestableheightofwatercrestingandthecriticalrate.Meanwhile,itcanre-confirmthebreakthroughtimeataspecificrate.Theoutputofacomparisonbetweenthis3-Dmodelandthereservoirnumericalsimulator(Eclipse)showsthemethodpresentedherecanbeappliedtoinvestigatethebehaviorofawatercrestingandtopredictthebreakthroughtimeatthebottomwaterdriverreservoir.

  • 标签: 动态分析软件 底水推进技术 临界流量分析 三维模型 水动力学
  • 简介:Inthisarticle,theanaglyphvideomakerisemployedforgeneratingrealistic3-DflowsandthesoftwareFlowAnimatorisdevelopedusingthattechnology.BasedonMicrosoftWindowsPresentationFoundation(WPF),thereal3-Dsceneissetupandmarkerparticlesaredistributedinitrandomlyinordertocreateamorenaturalflowscenario.ThetrajectoryoftheparticlemotioniscalculatedwithLagrangiandescriptionin3-Dspace.Duringthesimulation,theviewportcanbechangedinordertofocusondifferentpartsofthemodelbypanning,zooming,rotatingandinclinationvariationetc.Markerparticlesmayappearindifferentshapes:spheres,tracking-balls,cylindersandribbonsinordertofitdifferentflows.Itisthefirsttimethatthevideoanaglyphtechnologyisemployedinthe3-Dhydrodynamicsimulation,whichremovestheobstaclesfor3-Dscenestoberenderedonaflat-paneldisplay.

  • 标签: 三维流动模拟 立体 视频 MICROSOFT WINDOWS 应用
  • 简介:通过对比分析大清河系北支"63·8"、"96·8"、"7·21"3个典型洪水的雨情、水情,为未来大清河系北支防洪提供参考。

  • 标签: 大清河系北支 典型洪水 水情 雨情
  • 简介:Ageneralizedbendflowmodel,treatinga90°singlebendand60°continuousbends,wasdesignedtoquantitativelydescribe3-Dturbulencemechanismofcirculatingnot-fully-developedflowinopenchannelswithbends.The3-Dfluctuatingvelocitiesofturbulentflowweremeasuredandanalyzedwitha3-Dacoustic-Dopplervelocimeter.Formulafor3-Dturbulentintensitywasderivedusingthedimensionanalysisapproach.Expressionsofverticalturbulent-intensitydistributionswereobtainedwiththemultivariant-regressiontheory,whichagreewithexperimentdata.Distributionsofturbulentintensityandturbulentstresswerecharacterized,andtheirrelationshipswereconcluded.Inthebend-turbulent-flowcoreregion,longitudinalandlateralturbulent-intensitydistributionsarecoincidentwithlineardistribution,butinnear-wallregionarecoincidentwiththeGammadistribution.VerticalturbulentintensitydistributionsarecoincidentwiththeRayleighdistribution.Herein,itisconcludedthatthebendturbulenceisanisotropic.

  • 标签: 实验性学习 湍动弯曲流动 水道模型 三维湍流强度
  • 简介:11月17日,乌金峡水电站3号机组A级检修项目正式开工。本次检修主要是乌金峡水电站3号水轮发电机组A级检修作业中水轮发电机组各部件的分解、吊出、检查、处理、回装、调整及检修各项相关试验工作,并对3号水轮发电机组调速系统、油压装置及漏油装置、技术供水系统、机组轴承润滑及高压油顶起系统等部分辅助设备及系统检修、调整及修后相关试验工作。

  • 标签: 检修项目 3号机组 水电站 乌金 水轮发电机组 调速系统
  • 简介:根据东白城子河段近十几年试验监测资料,采用几种化学计量关系,分析论证了该河段的侵蚀CO2和游离CO2的含量周期性变化规律,为合理利用这一规律提供科学依据,并为该河段的水质监测评价工作节省了人力、物力、财力。

  • 标签: 有氧光合成 评价 化学计量
  • 简介:TheaddedresistanceofKVLCC2inshortandregularheadwaveshasbeenstudiedtheoreticallyandexperimentally.Modeltestsareperformedtodeterminehowwelltheasymptoticformula(Faltinsenetal.1980)predictsthetypicallevelofaddedresistanceinshortwaves.Becausetheasymptoticformulaneglectstheeffectsofshipmotions,itiscombinedwiththeoreticalmethodstocalculatetheaddedresistanceinlongwavesusinganfunctiontopredicttheaddedresistanceintheintermediatewavelengthregionwherebothshipmotionsandwavereflectionareimportant.Auniquefeatureofthisexperimentisthattheshipmodelisdividedintothreesegmentstoexploretheaddedresistancedistributionwithrespecttohullsegment.Thispaperdiscussesthesensitivityofexperimentalresultstothequalityoftheincidentregularheadwaves.Moreover,anovelprocedureforanalyzingaddedresistanceisdescribed.Finally,theexperimentallydeterminedaddedresistanceofKVLCC2iscomparedwiththeoreticalresults.Itisshownthattheaddedresistancefromthecombinedtheoreticalmethodsagreeswellwithexperimentalresultsinboththeintermediateandshortwaveregions.Theuseofhullsegmentsshowsthataddedresistanceisconcentratedprimarilyatthebow.

  • 标签: 短波 实验确定 评价 船舶运动 渐近公式 波阻力
  • 简介:4月8日由公司制造安装分局承担安装的黄河乌金峡水电站3号机组经过72小时试运行,比预计工期提前了36天顺利并网发电,这标志着乌金峡水电站已有3台机组投产发电,为力保丰水期投产发电奠定了坚实基础。

  • 标签: 3号机组 并网发电 水电站 乌金 制造安装 投产发电
  • 简介:继第四分局负责施工的TBM4于3月8日顺利贯通后,4月5日0时18分,制造安装分局负责施工TBM3穿透最后一段岩层,至此,公司两台TBM经过两年多的穿越,完成了全线30.2公里引水隧洞全面贯通的重大节点。

  • 标签: 贯通 制造安装 引水隧洞 TBM 施工 分局