Page 118 - 2024年第55卷第3期
P. 118

AnalysisoftheevolutionoficecharacteristicsintheYellowRiverunderfutureclimatescenarios

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                          ZHOUZhongyuan ,WANGTao,SUNYafei,CHENYuzhuang,LUJinzhi
                            (1.StateKeyLaboratoryofSimulationandRegulationofWaterCycleinRiverBasin,ChinaInstituteof
                                      WaterResourcesandHydropowerResearch ,Beijing 100038,China;
                                2.DepartmentofHydraulicEngineering,TsinghuaUniversity,Beijing 100084,China)
                  Abstract:Understandinghowfutureclimatechangewillaffectrivericecharacteristicsiscriticalforstudyingice
                  floodhazards ,hydropowerproduction,anddam management.Basedonthemeteorologicalobservationsinthe
                  YellowRiverbasinandthedailyaveragetemperaturedatafromeightGCMsoftheCMIP6 ,thesimulationcapabili
                  tyofeachGCMforthedailymeantemperatureoftheYellowRiverBasinduringthefloodingperiodbeforeandafter
                  thecorrectionofthequantiledeltamappingbiaswasevaluated ,andthefuturetemperaturetrendoftheYRBduring
                  theicefloodingperiodwaspredicted.Thepredictionmodelsofmaximumicethicknessandfreeze - updurationwere
                  establishedrespectively.Thefuturetrendsofmaximumicethicknessandfreeze - updurationintheNingxia - Mongo
                  liareachesoftheYellowRiverwerepredicted.Thestudyshowsthattheaveragetemperaturewarmingratesduring
                  theperiod2015 —2100intheYellowRiverBasininthethreeclimatescenariosofSSP1 - 2.6,SSP2 - 4.5,and
                  SSP5 - 8.5are0.014,0.031,and0.067℃ perdecade,respectively.ThemaximumicethicknessvaluesatBay
                  angaoleareexpectedtodecreaseby8.5,19.5,and39.5cm duringthiscentury,respectively.TheSSP2 - 4.5
                  scenarioshowsthatafter2070onlyacertainwidthofbankiceremainsintherivercross - sectionandalargeclear
                  channelexistsinthemiddleoftheriverwilloccurfrequently.Inthefuture,thefreezingdurationoftheYellow
                  River、SanhuhekouandToudaoguaisectionsoftheYellowRiverwillshowdifferentdegreesofshorteningtrend,a
                  mongwhichtheshorteningtrendofBayangaoleisthemostobvious,thefreezingdurationofthethreeclimatesce
                  nariosisshortenedby0.13 ,0.28and0.66daysperdecade,respectively,andthefreezingdurationoftheSanhu
                  hekouandtheToudaoguaisectionisrelativelyclose,whichis0.07,0.15,0.36daysperdecadeand0.08,0.17,
                  0.39daysperdecade,respectively.
                  Keywords:CMIP6;icefloodingperiod;rivericeconditions;climatechange;YellowRiverBasin
                                                                                    (责任编辑:李福田)


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                 EnergylossandflowcharacteristicsanalysisofamodelpumpturbineintheS - shaperegion

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                     WANGLike,YAOLiang,FENGJianjun ,ZHUGuojun ,LUJinling ,RUANHui
                   (1.StateKeyLaboratoryofEco - hydraulicsinNorthwestAridRegion,Xi’anUniversityofTechnology,Xi’an 710048,China;
                      2.InstituteofWaterResourcesandHydroelectricEngineering,Xi’anUniversityofTechnology,Xi’an 710048,China;
                              3.InstituteofHydraulicTechnology,Xi’anAeronauticalUniversity,Xi’an 710077,China)
                  Abstract:Inordertoadjustthestabilityofthepowergrid,thepumpedstoragepowerstationneedstostartand
                  stopfrequentlyandoperateunderdifferentworkingconditions.ThepumpturbineeasilyenterstotheScharacter
                  isticregion ,whichleadstotheincreaseinunitvibration,andtheunitinterconnectedfailure.Amodelpumptur
                  binewassetastheresearchobjectinthispaper.Theentropyproductiontheorywasusedtoanalyzetheenergy
                  losslawsunderdifferentoperatingconditionsintheS - shaperegion ,andtherelationshipbetweentheentropypro
                  ductiondistributionandtheinternalflowstructurewasclarified.Thetotalentropyproductionneartherunaway
                  conditionisthelargest ,whichisabout5.1timesofthatinthedesigncondition.Theproportionoffluctuationen
                  tropyproductioniscloseto80%.Asthedischargedecreases,theproportionofrunnerentropyproductiongradu
                  allydecreases ,whiletheproportionofguidevaneanddraftincreases.Thereisasignificantvortexfirstappeared
                  neartheshroudoftherunnerinlet,leadingtoahighentropyproductionareainthevanelessregion.Thevortex
                  graduallydevelopedtowardsthehubandthetangentialvelocityincreasedwhenthepumpturbineoperatesinthe
                  turbinebreakcondition.Awaterringwasformedattherunnerinlet ,hinderingthewaterflowintotherunner.A
                  highentropyproductionregionwithcirculardistributionappearedinthevanelessregion.Underthereversepump
                  condition ,thewaterflow collideswiththecounterclockwiserotatingbladesatthelow - pressureside,which
                  makesitdifficultforthewatertoentertheinteriorofthebladesandformsalarge - scalereversevortexstructure.
                  Thedoublerowcascadeisfilledwithalargenumberofvortexstructures ,leadingtoanincreaseintheentropy
                  productionrateoftheguidevane ,andpropagatedtowardsthestayvane.
                  Keywords:pumpturbine;S - shapedcharacteristics;entropyproduction;reversevortex
                                                                                    (责任编辑:王 婧)


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