水利英语 课件 U4 Hydraulics

Unit4

Hydraulics1.understandthebasiccontentsofhydraulics;2.knowabouttheengineeringapplicationofhydraulics;3.getfamiliarwiththedevelopmentofhydraulicresources;4.understandthetechnicalcharacteristicsoftheDujiangyanWaterConservancyproject;5.understandthehydraulicprincipleoftheDujiangyanWaterConservancyproject.Afterlearningthisunit,youshould:

PartⅠLead-in

PartⅡProfessionZoomIn

PartⅢCareerZoomIn

PartⅣReal-LifePracticeTask1Thinkaboutthefollowingquestions.PartⅠ

Lead-in1.Howdoyouunderstandhydraulicsasasubject?2.Listsomefamoushydraulicengineeringprojectsathomeandabroad.3.Whatimpressedyoumostaboutthehydraulicproject?Task

2Listentothedialogueandfillintheblankswithwhatyouhear.PartⅠ

Lead-in(A=lecturer;B=student)A:WhatbuildingsdoesDujiangyanconsistof?Dujiangyanisthewaterintakeprojectofthe(1)________projectintheChengduPlainarea,whichiscomposedofYuzui,theFeishaweir,andBaopingkou.WhatisthefunctionofYuzui?Yuzuiisaveryimportantwater(2)____________structure.Itsfunctionistoscientificallydistributetheflowofinnerandouterriver.WhatisthefunctionoftheFeishaweir?ThefunctionoftheFeishaweiristo(3)___________thesanddepositedintheinnerriver.WhatisthefunctionofBaopingkou?Itsfunctionisto(4)__________thefloodfromenteringChengduPlain.AndwhatistheplaneshapeoftheinnerriverinDujiangyan?TheinnerriverofDujiangyanisameanderingchannelontheplain,whichisconcavetothe(5)__________oftheriverchannel.B:irrigationB:A:B:A:B:A:B:A:conservancyremovecontrolbankPartⅠ

Lead-inwaterintakeproject取水工程Chengduplainarea成都平原地区weir[wɪə(r)]n.堰；拦河堤distribute[dɪˈstrɪbjuːt]v.分配deposit[dɪˈpɒzɪt]v.沉积meander[miˈændə(r)]v.蜿蜒而行concave[kɒnˈkeɪv]adj.凹面的ProfessionZoomInReading

Tobuildamodernsocialistcountryinallrespects,wemust,firstandforemost,pursuehigh-qualitydevelopment.DevelopmentisourParty’stoppriorityingoverningandrejuvenatingChina,forwithoutsolidmaterialandtechnologicalfoundations,wecannothopetobuildagreatmodernsocialistcountryinallrespects.Masteringsolidmaterialandtechnologicalfoundationsisthepremiseofpractice,andhydraulicsisasubjectbasedonpractice.Inthesenseofengineering,itisanempiricalscience.

Hydrostatics

Hydrostaticsstudiesthemechanicallawanditsapplicationofliquidinastaticorrelativelystaticstate,anddiscussestheinternalpressuredistributionofliquid,thepressureofliquidonasolidcontactsurface,thebuoyancyofliquidonfloatingbodyandsubmergedbodyandthestabilityoffloatingbody,soastosolvetheproblemsofwaterstoragecontainer,waterchannel,waterretainingstructureandstructuressinkingandfloatinginwater,suchasreservoir,waterstoragetank,waterpipeandgate,calculationofstaticloadofdams,ships,etc.译文返回原文水力学的研究分支和研究方法高质量发展是全面建设社会主义现代化国家的首要任务。发展是党执政兴国的第一要务。没有坚实的物质技术基础，就不可能全面建成社会主义现代化强国。掌握坚实的物质技术基础是实践的前提，水力学是建立在实践基础之上的一门学科，从工程意义上讲，它是一门经验学。水静力学水静力学研究液体静止或相对静止状态下的力学规律及其应用，探讨液体内部压强分布，液体对固体接触面的压力，液体对浮体和潜体的浮力及浮体的稳定性，以解决蓄水容器，输水管渠，挡水构筑物，沉浮于水中的构筑物，如水池、水箱、水管、闸门。堤坝、船舶等的静力荷载计算问题。Reading

Hydrodynamics

Hydrodynamicsstudiesthemechanicallawanditsapplicationunderthestateofliquidmovement,mainlydiscussestheflowlawofpipeflow,openchannelflow,weirflow,orificeoutflow,jet,andporousmediaseepage,aswellasthecalculationofvelocity,flow,waterdepth,waterpressureandhydraulicstructure,soastosolvethehydraulicproblemsinwatersupplyanddrainage,roads,bridgesandculverts,farmlanddrainageandirrigation,hydropowergeneration,floodcontrolandwaterloggingremoval,riverregulation,andportengineering.

Hydraulicexperimentmethod

Themostreliablemethodforhydraulicresearchistosystematicallyobserveandmeasuretheprototypewaterflowmovementandseekthelawofwaterflowmovementfromtheoriginaldata.Itistheessenceofhydraulicsandthebasicprincipleofwaterconservancyresearch.Ifitisimpossibleorthecostistoohigh,themainforceaffectingthewaterflowmovementcanbefoundinthelaboratoryaccordingtothemechanicalsimilarityprinciple,andthecorrespondingmodellawcanbeselectedtoapproximatelyreproducethewaterflowinacertainproportiontotheprototypeonthemodelwithareducedscale.Accordingtothemeasurementofthewaterflowmovementofthemodel,thestateandvariousparametersoftheprototypewaterflowmovementcanbeestimated.Asanimportantsupplementtomathematicalanalysisandexperimentalanalysis,thismethodcanbecalledtheexperimentalmethodorpracticalmethod.译文返回原文水动力学水动力学研究液体运动状态下的力学规律及其应用，主要探讨管流、明渠流、堰流、孔口流、射流、多孔介质渗流的流动规律，以及流速、流量、水深、压力、水工建筑物结构的计算，以解决给水排水、道路桥涵、农田排灌、水力发电、防洪除涝、河道整治及港口工程中的水力学问题。水力学实验方法对原型流动进行系统的观察和测定，从原始数据中寻求流动规律，是水力学研究的最可靠的方法。它是水力学的精髓，也是水利研究的基本原则。如果实际上不可能，或需要费用太大，则可在实验室根据力学相似原理，找出影响流动的主要作用力，选用相应的模型律，以缩小的比例尺在模型上近似地重现和原型成一定比例的流动，根据模型流动的测定，估算原型流动的状态和各种参数，是数理分析和实验分析的重要补充，它是以白金汉提出的，定理为依据。这种方法，可以称为试验法或实践法。Reading

Hydraulicnumericalsimulationmethod

Numericalsimulationisnotonlyaresearchmethodusedsincetheadventofthecomputerbutalsoasupplementtomathematicalanalysis.Whentheresearchobjectistoocomplex,thecontrolequationisnonlinearandtheboundaryconditionsareirregular,anditisdifficulttoobtaintheanalyticalsolutionbyusingtheexistingmathematicalandmechanicalmethods.Inthissituation,thenumericalmodelcanbeestablished,theprogramcanbecompiled,andthedigitalresultsorgraphscanbeobtainedbycomputercalculation.

Comparedwithexperimentalresearch,numericalsimulationhasgreaterflexibilityandcontrolrangeinboundaryconditionsandfluidphysicalproperties.Fortheproblemsthatmustbestudiedexperimentally,numericalsimulationcanprovideavaluablereferenceforexperimentalplanning&layoutandtheselectionoftestinstruments.Thismethodiscalledthenumericalsimulationmethod.Itisamethodofphysicalmodelexperimentmethodservice.Everythingdependsonthephysicalmodelexperimentmethod.Itisonlyatoolofthephysicalmodelexperimentmethod.译文返回原文水力学数模方法数值模拟是计算机问世以来所采用的研究方法，也是数理分析的一种补充。当研究对象过于复杂、控制方程非线性、边界条件不规则，利用现有的数学力学方法难以得出解析解时，可以建立数值模型，编制程序，通过计算机运算得出数字结果或图线。和实验研究相比，数值模拟在边界条件和流体物理性质上有更大的灵活性和控制范围。对于必须进行实验研究的问题先进行数值模拟，可以对实验规划和布置、测试仪器的选择提供有价值的参考。这种方法叫做数值模拟法，是物理模型实验方法服务的一种方法，一切依赖于物理模型实验方法。它只是物理模型实验方法的一种工具。priority[praɪˈɒrəti]n.重点govern[ˈɡʌv(ə)n]v.治理rejuvenate[rɪˈdʒu:vəneɪt]v.使更有活力empirical[ɪmˈpɪrɪk(ə)l]adj.以经验（或实验）为依据的；经验主义的hydrostatics[haɪdrə(ʊ)ˈstætɪks]n.流体静力学static[ˈstætɪk]adj.静态的buoyancy[ˈbɔɪənsi]n.浮力hydrodynamics[ˌhaɪdrəʊdaɪˈnæmɪks]n.流体动力学，水动力学orifice[ˈɒrɪfɪs]n.孔，穴，腔jet[dʒet]n.喷射流porous[ˈpɔːrəs]adj.多孔的culvert[ˈkʌlvət]n.涵洞waterlogging[ˈwɔːtəˌlɔgiŋ]n.涝systematically[ˌsɪstəˈmætɪkli]adj.系统地prototype[ˈprəʊtətaɪp]n.原型essence[ˈes(ə)ns]n.本质reproduce[ˌriːprəˈdjuːs]v.再生产；再制造proportion[prəˈpɔːʃ(ə)n]n.部分；比例parameter[pəˈræmɪtə(r)]n.规范；范围numerical[njuːˈmerɪk(ə)l]n.数字的simulation[ˌsɪmjuˈleɪʃ(ə)n]n.模拟supplement[ˈsʌplɪmənt]n.补充nonlinear[nɒnˈlɪnɪə]adj.非线性的analytical[ˌænəˈlɪtɪk(ə)l]adj.分析的flexibility[ˌfleksəˈbɪləti]n.灵活性reference[ˈrefrəns]n.参考inallrespects全面firstandforemost首先governingandrejuvenatingChina执政兴国internalpressure内部压强floatingbody浮体openchannelflow明渠流weirflow堰流orificeflow孔口出流porousmedium多孔介质waterloggingremoval除涝riverregulation河道整治portengineering港口工程similarityprinciple相似原理boundarycondition边界条件numericalmodel数值模型numericalsimulation数值模拟physicalmodel物理模型，实体模型Hydrodynamicsstudiesthemechanicallawanditsapplicationunderthestateofliquidmovement,mainlydiscussestheflowlawofpipeflow,openchannelflow,weirflow,orificeoutflow,jet,andporousmediaseepage...译文：流体力学研究液体运动状态下的力学规律及其应用，主要探讨管流、明渠流、堰流、孔流、射流、多孔介质渗流的流动规律……注释：Hydrodynamics，流体力学；对应Hydrostatics，流体静力学。porousmediaseepage，多孔介质渗流，在水力学中主要研究基础计算理论，在土力学中研究在土体结构中的应用。❶Itistheessenceofhydraulicsandthebasicprincipleofwaterconservancyresearch.Ifitisimpossibleorthecostistoohigh,themainforceaffectingthewaterflowmovementcanbefoundinthelaboratoryaccordingtothemechanicalsimilarityprinciple.译文：它（水力试验研究）是水力学的精髓，也是水利研究的基本原理。如果无法完成或费用太高，则可根据机械相似原理在实验室找出影响水流运动的主要力量。注释：在由if引导的条件状语从句中，themainforce为主语，affectingthewaterflow为定语修饰主语，accordingtothemechanicalsimilarityprinciple为补语。❷Whentheresearchobjectistoocomplex,thecontrolequationisnonlinearandtheboundaryconditionsareirregular,anditisdifficulttoobtaintheanalyticalsolutionbyusingtheexistingmathematicalandmechanicalmethods.译文：当研究对象过于复杂、控制方程非线性、边界条件不规则时，利用现有的数学和力学方法难以得出解析解。注释：此句中的条件多元，且主语不相同，采用多个条件状语从句并列的形式来表达。“Itisdifficultto…”是主句。❸ReadingTask1Matchthewordsontheleftwiththeirmeaningsontheright.ReadingTask

2Completethefollowingsentenceswiththewordsorexpressionsinthebox.Changetheformifnecessary.Hydrostaticsmainlystudiesthephysicallawofwater-appliedforceandgenerallyuses____________tomeasurewater-appliedforce.Thedistributionlawofhydrostaticpressurealongthewaterdepthisthatthedeeperthewaterdepth,the___________thepressure.Hydrostaticpressureproducesa______________onthefloatingbody.Hydraulicsisasciencebasedonexperiments,andmany______________________ofhydraulicsareobtainedfromexperimentalresearch.Hydraulicnumericalsimulationisamoreconvenienttestmethod,whichcanprovide____________datathanphysicalmodeltests.1.2.3.4.5.pressuregreaterbuoyantforcecalculationformulascalculationformulasgreateraccuratepressurebuoyantforceaccurateReadingTask

3Decidewhetherthefollowingstatementsaretrue(T)orfalse(F)accordingtothetext.Hydrodynamicsmainlystudiestheflowlawofwaterflowandcalculatesthevelocity,flow,waterdepthandpressureofwaterflow.Hydraulicsisanexperimentalscience,andNewton’slawofmechanicsisitsbasictheory.However,itisnecessarytouseexperimentstoestablishthebasiccalculationtheory.Thehydraulictestisthebasicmethodtomasterthelawoffluidmovement,buttheactualhydraulicengineeringbuildingscannotbeputintothelaboratoryforatest,andthereducedmodelneedstobeusedforthetest.Theexperimentalmodelofhydraulicphysicscanmeetthetestrequirementsonlybyreducingthemodelaccordingtothegeometricscale.Inpractice,thehydraulicphysicalexperimentmodelcaneasilymeetallthemechanicalsimilarityconditions.()1.()2.()3.()4.()5.TTFFTListeningListentothedialogueandfillintheblankswithwhatyouhear.Hey,haveyouheardaboutthedifferent(1)________ofwaterresourcesengineering?No,canyouexplainmore?Sure!Hydrostaticsfocusesonthemechanicallawanditsapplicationofliquidinastaticorrelativelystaticstate.Ithelpssolveproblemsrelatedtowaterstorage,channels,retainingstructures,andsinking/floatingstructureslikereservoirsandgates.Thatsoundsinteresting.Whatabouthydrodynamics?Hydrodynamicsstudiesthemechanicallawanditsapplicationunderliquidmovementconditions.Ithelpssolvehydraulicproblemsinwatersupplyand(2)________systems,roads,bridges,culverts,farmlanddrainageand(3)________,hydropowergeneration,floodcontrol,andriverregulation.A:B:branches(A=Mary;B=Bill)A:B:A:drainageirrigationListeningSohydrostaticsdealswithliquidsatrestorwithminimalmovement,whilehydrodynamicsfocusesonliquidsin(4)________?Exactly!There’salsothehydraulicexperimentmethodtostudyhydraulics.Observationisthemostfundamentalmethod,whilelaboratoryexperimentsaremoreefficientandprecise.That’sfascinating.Andwhataboutthehydraulicnumericalsimulationmethod?Thehydraulicnumericalsimulationmethodusescomputerstoestablishnumericalmodels,compileprograms,andobtaindigitalresultsorgraphsforcomplexresearchobjectswith(5)________controlequationsandirregularboundaryconditions.Eachbranchhasitsownfocusandcontributestosolvingdifferentaspectsofwaterresourcesengineeringproblems.B:motionA:B:A:B:nonlinearListeningwaterresourcesengineering水资源工程mechanicallawanditsapplication机械定律和应用waterstorage储水retainingstructure支撑结构sinking/floatingstructure沉降/浮动结构underliquidmovementconditions在运动流体条件下watersupply供水riverregulation河流管理SpeakingMakeasmallpresentationonhydraulicsbasedonthedescriptionbelow.Thelisteningexerciseabovecanbeyourreference.

Hydraulicsisadisciplinebasedonpractice,andmasteringasolidfoundationinmaterialsandtechnologyisaprerequisiteforthepracticeofwaterconservancyscience.Howdoyouunderstandthatinthesenseofengineering?Isitanempiricalscience?CareerZoomInReading

DujiangyanislocatedontheMinjiangRiver.Thewaterinlet,Baopingkou,isexcavatedontheleftbanknearYuleiMountain.InordertointroducethewateroftheMinjiangRiverintoBaopingkou,JingangDikeissetintheriverbedoftheMinjiangRiverupstreamofBaopingkou,whichdividestheMinjiangRiverintotwoparts:theinnerriverandtheouterriver.Theouterriveriswiderbutshallower,whiletheinnerriverisnarrowerbutdeeper.Theinnerriverisconcaveandcurved,andtheouterriverisconvexandcurved.ThefrontendoftheJingangDikeisYuzui,andtheendisclosetotheoutersideoftheBaopingkou.Thereisagap,whichisequippedwithalowsandflushingweir,theFeishaweir.ThewateroftheinnerrivercanoverflowtheFeishaweirandentertheouterriver.译文返回原文都江堰的水力学原理都江堰位于岷江上。进水口宝瓶口位于郁雷山附近的左岸。为了将岷江水引入宝瓶口，在宝瓶口上游的岷江河床上设置了金刚堤，将岷江分为内河和外河两部分。外河较宽但较浅，而内河较窄但较深。内河是凹的和弯曲的，外河是凸的和弯曲。金刚堤的前端是鱼嘴，末端靠近宝瓶口的外侧。有一个缺口，里面装了一个低冲沙堰，飞沙堰。内河的水可以溢出飞沙堰，进入外河。Reading

1.Yuzui

Yuzui,lookinglikeafishmouth,islocatedatthefrontendoftheJingangDike.Yuzuiisstreamlinedtoreduceflowresistance.ThekeyfunctionofYuzuiistodeterminethewidthoftheinnerandouterrivers.Asisknown,theouterriveriswidebutshallow,andtheinnerriverisnarrowbutdeep.Duringthedryseason,thewaterlevelislow.Thewaterpassingareaoftheouterriverisroughly30%ofthetotalwaterpassingareaandthatoftheinnerriveris70%.Theflowdistributionratioofinnerandouterriversis7:3.Duringthefloodseason,whenthewaterlevelrisessharply,thewidthoftheouterriverbecomeslarge,andtheincreaseofthewaterdischargeareaisalsolarge.Thewaterdischargesurfaceoftheouterriverreaches70%ofthetotalwaterdischargearea,whiletheinnerriverisnarrow,andtheincreaseofthewaterdischargeareaissmall,accountingfor30%.Theflowdistributionratiooftheinnerandouterriversis3:7.译文

1.鱼嘴鱼嘴位于金港堤的前端，看起来像一个鱼嘴。鱼嘴是流线型的，以减少流动阻力。鱼嘴的主要功能是决定内外河流的宽度。众所周知，外河宽而浅，内河窄而深。旱季时，水位较低。外河的过水面积约占总过水面积的30%，内河的过水量为70%。内外河流量分配比为7:3。在汛期，当水位急剧上升时，外河的宽度变大，排水面积的增加也很大。外河泄水面占总泄水面的70%，内河泄水面较窄，泄水面增加较小，占30%。内外河流量分配比为3:7。返回原文Reading译文

2.TheFeishaweir

TheFeishaweirstandsattheendofJingangDike,neartheupstreamofBaopingkou.TheFeishaweirisalowoverflowweir.Duringfloodseason,thefloodisdischargeddownstreamthroughtheFeishaweir,whichismainlyusedforsandflushing.

SandflushingprincipleoftheFeishaweir:Locatedonaconcavebank,theinnerriverisacurvedriverchannel.Accordingtotheknowledgeofmodernhydraulics,thereisatransversecirculationintheinnerriver.Thecirculationwillwashthesedimentoftheriverchanneltotheconvexbank,i.e.,theFeishaweir,anddischargeitfromthetopoftheflyingsandweirtotheouterriver,soastoachievethegoalofsandflushingoftheinnerriverandensurethattheinnerriverwillnotbesilted.

2.飞沙堰飞沙堰位于金港堤的尽头，靠近宝瓶口的上游。飞沙堰为低溢流堰。汛期洪水通过飞沙堰向下游排泄，飞沙堰主要用于冲沙。飞沙堰的冲沙原理：内河位于凹岸，为弯曲河道。根据现代水力学的知识，内河存在横向环流。循环将河道泥沙冲刷到凸岸，即飞沙堰，并从飞沙堰顶部排放到外河，以达到内河冲沙的目的，确保内河不淤积。返回原文Reading译文

3.Baopingkou

Likeabottlemouth,Baopingkouisadeepandnarrowwaterinlet.Inadditiontowaterdiversioninthedryseason,itsfunctionismainlytorestrictthefloodfromenteringChengduPlain.

FloodcontrolprincipleofBaopingkou:Accordingtothemodernhydraulictheory,duringthefloodperiod,thecontractioncoefficientofthefrontsideofBaopingkouislarge,andthedownstreamflowdiffusioncoefficientisalsolarge,whichresultsinlargeheadlossandsmallsectionwidthoffloodpassingthroughBaopingkou.Therefore,thefloodpassingthroughBaopingkoucanbelimitedtoacertainextent.

3.宝瓶口宝瓶口就像一个瓶口，是一个又深又窄的进水口。除枯水期调水外，其作用主要是限制洪水进入成都平原。宝瓶口的防洪原则：根据现代水力学理论，在汛期，保坪口前侧的收缩系数较大，下游的流量扩散系数也较大，导致通过保坪口的洪水水头损失较大，断面宽度较小。因此，通过宝瓶口的洪水可以在一定程度上受到限制。返回原文bank[bæŋk]n.岸，边坡convex[ˈkɒnveks]adj.凸面的flush[flʌʃ]v.冲overflow[ˌəʊvəˈfləʊ]v.漫出，溢出streamline[ˈstriːmlaɪn]v.使成流线型transverse[ˈtrænzvɜːs]adj.横（向）的；横断的sediment[ˈsedɪmənt]n.沉积物silt[sɪlt]v.（使）淤塞coefficient[ˌkəʊɪˈfɪʃ(ə)nt]n.系数diffusion[dɪˈfjuːʒn]n.扩散；传播flowresistance流动阻力ChengduPlain成都平原keyfunction关键功能dryseason枯水季floodseason洪水季transversecirculating横向环流InordertointroducethewateroftheMinjiangRiverintoBaopingkou,JingangDikeissetintheriverbedoftheMinjiangRiverupstreamofBaopingkou,whichdividesMinjiangRiverintotwoparts:theinnerriverandtheouterriver.译文：为了将岷江水引入宝瓶口，在宝瓶口上游的岷江河床中设置金刚堤，将岷江一分为二：内江和外江。注释：which引导的非限定性定语从句解释了JingangDike的作用。❶Yuzui,lookinglikeafishmouth,islocatedatthefrontendoftheJingangDike.Yuzuiisstreamlinedtoreduceflowresistance.译文：鱼嘴位于金刚堤的最前端是鱼嘴，因外形似鱼嘴而得名。鱼嘴呈流线型，用以减少水流阻力。注释：两句话里的looking和toreduce都是非谓语动词形式。非谓语动词可减少动词并列和句子结构层次，从而使表达更为精炼。如此两句，如果不使用非谓语动词形式，则会有Yuzuiis…,andlookslike…Yuzuiis…andreduces…这种冗长的句式。❷Thecirculationwillwashthesedimentoftheriverchanneltotheconvexbank,i.e.,theFeishaweir,anddischargeitfromthetopoftheflyingsandweirtotheouterriver,soastoachievethegoalofsandflushingoftheinnerriverandensurethattheinnerriverwillnotbesilted.译文：环流将河道沉沙冲向凸岸，即飞沙堰，从飞沙堰顶排到外江，实现对内江冲砂的目标，保障内江不会淤积。注释：在此句中，主语thecirculation执行的动作有wash，discharge，achieve，ensure四个。为避免多个动词连用，导致信息表达失焦，保留前两个做谓语动词，把表示目的的后两个处理为非谓语动词形式，从而让句子显得逻辑和层次都很清楚。❸ReadingTask1Basedonthepassage,choosethecorrectanswerforeachstatement.WhatarethetwopartsofJingangDikethatweresetuptointroducewaterfromtheMinjiangRiverintoBaopingkou?A.upstreamanddownstreamB.innerriverandouterriverC.internalandexternalriverD.insideriverandoutsideriver1.ReadingWhatisYuzui’skeyfunction?A.DeterminethedepthoftheinnerandouterriversB.DeterminethewidthoftheinnerandouterriversC.DeterminethecurrentvelocityoftheinnerandouterriversD.Determinethedischargeoftheinnerandouterrivers2.ReadingAsisknown,theouterriveriswidebutshallow,howabouttheinnerriver?A.WidebutdeepB.NarrowbutshallowC.NarrowbutdeepD.Widebutshallow3.ReadingDuringfloodseason,thefloodisdischargeddownstreamthroughtheFeishaweir,whichismainlyusedforwhat?A.Forsandflushing.B.Forirrigating.C.Forshorecleaning.D.Fortransporting.4.ReadingBaopingkouislikeabottlemouth,adeepandnarrowwaterinlet.Inadditiontoregulatingwaterduringthedryseason,whichofthefollowingsisitsmainfunction?A.TorestrictthefloodfromenteringChengduurbanarea.B.TorestrictthefloodfromenteringSichuanBasin.C.TorestrictthefloodfromenteringChongqingPlain.D.TorestrictthefloodfromenteringChengduPlain.5.ReadingTask

2Decidewhetherthefollowingstatementsaretrue(T)orfalse(F)accordingtothetext.Yuzuiisadiversiondike.Itsfunctionistoreasonablydistributetheflowofinnerandouterrivers.Yuzuirevealsveryadvancedhydraulicconstructionengineeringthoughts.Theinnerriverisverylongbecauseitneedstodrawmoreflow.Thefeishaweirisanoverflowweir,whichisusedtodischargeexcessflowtotheouterrivertopreventfloodsfromenteringChengduPlain.Baopingkouisthewaterinletoftheirrigationcanal.Itsmainfunctionistoensurethatthereisenoughwatertotransporttothetankfarminthedryseasonbuttoavoidfloodsthreateningthefloodcontrolsafetyofthetankfarm.()1.()2.()3.()4.TTTF()5.F

Itisabranchofhydraulicsthatstudiesthelawofflowmovementinriversandcanalswithfreewatersurfaceundertheactionofgravity.Openchannelflowischaracterizedbyafreewatersurface.Researchonopenchannelhydraulicswhentheupstreamflowchanges,thechannelsectionshape,sidewallroughnessandchannelbottomslopechange,orthedownstreamcontrolconditionschange,aswellasotherouterdisturbances,areaddedtothewatersurface,variousformsofwatersurfacelines(waterdepth)andsectionvelocitydistributionintheopenchannelwillbeformed.

Openchannelsincludeprismaticartificialchannelsandnon-prismaticnaturalchannels.Theopenchannelflowcanbedividedintotwocategories:theopenchannelconstantflow(alsosteadyflow)wherehydraulicfactorsdonotchangewithtime,andtheopenchannelunsteadyflowwherehydraulicfactorschangewithtime.

Constantnon-uniformflow

Hydraulicfactorsdonotchangewithtimebutchangealongtheriverpath,whichcanbedividedintogradualflowandrapidchangeflow.译文OpenChannelHydraulics明渠水力学研究重力作用下具有自由面的河渠水流运动规律，是水力学的分支学科。明渠水流的特点是具有自由水面。明渠水力学的研究当上游来流量变化或河渠断面形状、边壁糙度和渠底坡度变化，或下游控制条件改变，以及其他外来扰动加之于水面时，明渠内形成的各种形式的水面线(水深)及断面流速分布等。明渠包括棱柱形断面的人工渠道和非棱柱形的天然河道。明渠水流分为两大类：水力因素(水深、流速、比降等)不随时间而变化的为明渠恒定流(亦称定常流)；水力因素随时间而变化的为明渠非恒定流。恒定非均匀流水力因素不随时间变化，但随沿程变化，又分为渐变流和急变流两种。返回原文

(1)Graduallyvariedsteadyflow.Hydraulicfactorschangelittlealongthewayandcanbeignored.

(2)Rapidlyvariedsteadyflow.Commontransitionflowpatternsinopenchannelsincludeatransitionfromslowflowtorapidflow,atransitionfromrapidflowtoslowflow,flowinvariablewidthchannels,bendflow,etc.

Unsteadyflowinopenchannel

Theflowinnaturalchannelsisalmostalwaysunsteadyintimeandnon-uniforminspace,suchasrunoffformedbyrainstorms,floodwavemovementinriversandcanals,dambreakwaveafterdamfailure,surgecausedbylandslideonreservoirbankorriverbank,tidesandtsunamisontheseashore,andchangesofwaterlevelandflowindiversionchannels,etc.译文

(1)恒定渐变。水力因素沿程变化小，可以忽略。

(2)恒定急变流。常见的明渠过渡流态有：从缓流到急流的过渡(如跌水、堰流等);从急流到缓流的过渡(如水跃)；变宽度河渠中的流动；弯道水流(急流时可见冲击波)等。明渠急变流常是三维流动，伴有明显的能量损失，宜用动量原理或通过模型验解决。明渠不恒定流天然河渠中的水流几乎都是时间上不恒定和空间上非均匀的流动，如：暴雨形成的径流；河渠中洪水波运动(伴有河床冲淤变化的洪水演进问题)；堤坝失事后的溃坝波；库岸或江岸滑坡激起的涌浪；海滨的潮汐、海啸；水电站或水泵站启闭过程中，上下游引水渠中水位、流量的变化；通航建筑物及灌溉系统充泄水时变水头出流等都属明渠不恒定流。返回原文openchannel明渠gravity[ˈɡrævəti]n.重力sidewallroughness边壁糙度disturbance[dɪˈstɜːbəns]n.干扰sectionvelocitydistribution断面流速分布prismatic[prɪzˈmætɪk]adj.棱柱形的artificialchannels人工渠道constantflow恒定流unsteadyflow非恒定流constantnon-uniformflow恒定非均匀流transitionflowpatterns过渡流态damfailure堤坝失事tsunami[tsuːˈnɑːmi]n.海啸ListeningListentothedialogueandfillintheblankswithwhatyouhear.ThecommentatoroftheDujiangyanexhibitionhallexplainedthehistoricalsignificanceofDujiangyantostudentsmajoringinwaterconservation.(A=commentator;B=student)Dujiangyanisawaterconservancyprojectbuiltmorethan2,000yearsago,anditisalsotheonlywaterconservancyprojectthathasbeenrunningcontinuouslyfromancienttimestothepresent.Whatelseancientwater(1)____________projectsdoyouknow?Ireadaboutancient(2)___________andancientBabylonsirrigationsystems,buttheyhavebeenlostinthelongriverofhistory.DoyouagreethatDujiangyanisagreat“(3)______________project”,makingfulluseofnaturalresourcestoservemankindwithoutdestroyingnaturalresources?A:B:conservancyEgyptA:ecologicalListeningThereasonwhyDujiangyancanstandformorethan2,000yearsisthatitconformsto(4)________laws.TheDujiangyanWaterConservancyprojectisreallythecrystallizationofthewisdomoftheancientChinesepeople.Morethan2,000yearsago,theancientChinesepeoplegraduallymasteredthelawofwater.Eveninmoderntimes,wehavenotbeenabletofullygraspthelawofriverwaterand(5)______________movement.DoesDujiangyanstillhavepracticalsignificanceformodernwaterconservancyprojects?ThewatercontrolthoughtembodiedinDujiangyanisstillofgreatsignificancetomodernwaterconservancyprojects.Isthereanydifferencebetweenmodernandancientwaterconservancyideas?Modernwaterconservancyideasgenerallyrefertohighertechnologicallevels,whileDujiangyanappealsmoreharmoniouslytonature.B:naturalA:B:sedimentA:B:A:B:waterconservancyproject水利工程irrigationsystems灌溉工程naturalresources自然资源conformto符合crystallizationofth