工程流體力學智慧樹知到期末考試答案章節(jié)答案2024年山東大學

工程流體力學智慧樹知到期末考試答案+章節(jié)答案2024年山東大學Agardenhosenozzleisdesignedtohaveamuchhighervelocityattheentranceofthenozzleasopposedtotheexit.TrueorFalse?（）

答案:錯Whentheflowisuniformlydistributedoverasectionofthecontrolsurfacewhereflowoccurstheintegraloperationsaresimplified.TrueorFalse?（）

答案:對Modeldesignconditionsarealsocalledsimilarityrequirementsormodelinglaws.（）

答案:對Thepressuredropperunitlengththatdevelopsduetofrictioncannotgenerallybesolvedanalytically.（）

答案:對FlowmetersbasedontheBernoulliequation,usedtomeasureflowratesinopenchannelssuchasflumesandirrigationditches,includedeviceslikethesluicegateandthesharp-crestedweir.TrueorFalse?（）

答案:對Anexampleofadeformingcontrolvolumeis（）

答案:balloonAstraightpipecausesagreaterheadlossthanabentpipe.（）

答案:錯TheBernoulliequationcanbederivedfromtheenergyequation.TrueorFalse?（）

答案:對Governingequationsexpressedintermsofdimensionlessvariablesleadtotheappropriatedimensionlessgroups.（）

答案:對Ahurricaneisanexampleofa____.()

答案:FreevortexWhatistheno-slipconditionthatallfluidssatisfy?（）。

答案:theexperimentalobservationthatthefluid“sticks”tothesolidboundaries%1.theexperimentalobservationthatthefluiddoesn't“stick”tothesolidboundaries%1.noneWhataccuracyisgenerallyexpectedfromtheMoodychart?()

答案:10%Thegasconstant,R,dependsonwhat?（）。

答案:themolecularweightofthegasTheincompressibilityassumptionmadeinthederivationoftheBernoulliequationcanyieldconsiderableerrorinwhichofthefollowingcases?（）。

答案:ChangeinforceexertedonthefluidWhenmeasuringthestaticpressure,onewaytodosowouldbetodowhat?（）。

答案:DrillaholealongtheflatsurfaceandattachapiezometertubeAtankisfilledwithseawatertoadepthof12ft.Ifthespecificgravityofseawateris1.03andtheatmosphericpressureatthislocationis14.8psi,theabsolutepressure(psi)atthebottomofthetankismostnearly（）。

答案:20.2Asa“ruleofthumb,”aperfectgasmaybeconsideredincompressibleforwhichrangeofMachnumbers?（）。

答案:lessthan0.3Whatisanothertermfortheviscouseffectsthatcauseafluidtosticktothewallofapipe?()

答案:Theno-slipboundaryconditionThebroadsubjectoffluidmechanicscanbegenerallydividedinto____.（）。

答案:fluidstaticsandfluiddynamicsIfshaftworkisinvolvedthenthelocalflowmustbe____.()

答案:unsteadyThestandardunitnormalvector()

答案:isnormaltothesurfacepointingoutwards.Theexitpressureforanincompressiblefluidjetisequaltowhat?（）。

答案:surroundingoratmosphericpressureAnothertermforthespeedofsoundiswhat?（）。

答案:acousticvelocityIfacylinderisrotatedinauniformflow,whathappenstothestagnationpoint?()

答案:Itmovesalongthesurfaceofthecylinder,andcanevenmoveoffofthesurfaceofthecylinder.WhatisthesymbolfortheCauchynumber?()

答案:CaA2-in.diametershaftissupportedbytwosleeves,eachoflength=2in.Theinternaldiameterofthesleevesis2.1in.Theradialspacebetweentheshaftandthesleevesisfilledwithanoilofviscosity=8×10-3lb-s/ft2.Iftheshaftisrotatedataspeedof600rpm,theviscoustorque(ft-lb)ontheshaftismostnearly（）。

答案:0.15TheGermanprofessorLudwigPrandtlintroducedtheconceptofwhat?（）。

答案:fluidboundarylayerFlowsincanals,rivers,spillways,andstillingbasinsareallexamplesofflowswithafreesurface.（）

答案:對ThegreatLeonardodaVincidescribedthroughsketchesandwritingsmanydifferenttypesofflowphenomena,trueorfalse?（）

答案:對TheBernoulliequationcanbemodifiedforcompressibleflows.TrueorFalse?（）

答案:對Thefewerthenumberofpitermsthemoresimpletheproblem.（）

答案:對GeometricandReynoldsnumbersimilarityisusuallynotrequiredformodelsinvolvingflowthroughclosedconduits.（）

答案:錯Examplesofasourceandasinkareapumpandaturbine.TrueorFalse?（）

答案:對Whenvelocityratiosandaccelerationratiosareconstantthroughouttheflowfield,kinematicsimilarityexistsbetweenthemodelandtheprototype.（）

答案:對Thevelocityatastagnationpointwillbegreaterthanthevelocityatsurroundingareas.TrueorFalse?（）

答案:錯Thetimederivativeassociatedwithasystemisalwaysthesameasthederivativeassociatedwithacontrolvolume.TrueorFalse?（）

答案:錯TheEulernumberisundoubtedlythemostfamousdimensionlessparameterinfluidmechanics.（）

答案:錯Thelinesthataretangenttothevelocityvectorsthroughouttheflowfieldarecalledsteadyflowlines.TrueorFalse?（）

答案:錯Variablescanbeclassifiedintothreegeneralgroups:geometry,materialproperties,andexternaleffects.（）

答案:對Theamountofmassinasystemisconstant.TrueorFalse?（）

答案:對Apotentialflowvortexisrotational.TrueorFalse?（）

答案:錯Thepressuredropinapipeisgreateriftheflowis____.()

答案:turbulentWaterstridersarecapableofcovering100bodylengthsinonesecond.TrueorFalse?（）

答案:對Ifdensityisknown,thevolumeflowratecanbeusedtofindthemassflowrate.TrueorFalse?（）

答案:對ForsomeproblemsitismoreconvenienttoexpressthevariousdifferentialrelationshipsincylindricalcoordinatesratherthaninCartesiancoordinates.TrueorFalse?（）

答案:對Ifasourceandasinkareplacedashortdistanceapart,butnotontopofeachother,whattypeofbodyisformed?()

答案:ARankineovalWhichshearstressisdominantintheviscoussublayer?()

答案:Laminar.WhichtermoftheNavier-Stokesequationresultsintheequationsnon-linearity?()

答案:AccelerationAnozzlemeterresultsinamoreidealflowthananorificemeter.（）

答案:對Arepresentationofaphysicalsystemthatmaybeusedtopredictthebehaviorofthesysteminsomedesiredrespectiswhat?()

答案:ModelWhattermisusedwhenthefluidpressureisreducedtothevaporpressure?（）。

答案:CavitationAnadiabaticprocessmeansthatthereisnoheattransferandno____.（）。

答案:frictionTheMachnumberandwhatothernumbercannotbeusedinthesameproblem?()

答案:CauchynumberPotentialtheorypredictsthatdragonacylinderinauniformflowiszero,apredictionthatisnotactuallytrue.Thisdiscrepancyiscalled()

答案:D'Alembert'sparadox.Steady,fullydevelopedpipeflowexperiencesno____.()

答案:AccelerationWhatisthematerialderivativeusedfor?()

答案:Todescribetimeratesofchangeforagivenparticle.TheFroudenumberarisesbecauseoftheinclusionofwhatinaproblem?（）

答案:GravityAccordingtothemomentumequation,thetimerateofchangeoflinearmomentumisequalto:()

答案:resultantforceThehydraulicgradelineandwhatelsearegraphicalformsoftheBernoulliequation?（）。

答案:viscouslineWhichhasa“flatter”velocityprofile?()

答案:Turbulentflow.Ifthestreamlinesformradiallines,whatconfigurationdotheequipotentiallinesassume?()

答案:Concentriccircles.Raindropswitharadiuslessthan0.5mmarewhatshape?（）。

答案:sphericalFortruemodels,howmanyscaleswilltherebe?()

答案:OneThepitermsmustalwaysbewhat?()

答案:dimensionlessWhichofthethreemetertypesisthemostaccurate?()

答案:VenturiWhatisastreakline?（）

答案:Alltheparticlesinaflowthathavepreviouslypassedthroughacommonpoint.TheReynoldstransporttheoremprovidestherelationshipbetween()

答案:Thetimerateofchangeofanextensivepropertyofthesystemandthecontrolvolume.Newton'ssecondlawdealswith____momentumandforces.()

答案:systemAnobjectweighs275Nwhenfullyimmersedinwaterand325Nwhenfullyimmersedinoilofspecificgravity0.9.Thevolumeoftheobject(m3)ismostnearly（）。

答案:0.05Themostdifficultstepinthemethodofrepeatingvariablesis____.()

答案:listingallofthevariablesthatareinvolvedintheproblemForthelaminarflowofaNewtonianfluid,theshearstressisproportionaltothe____.()

答案:velocitygradientWheredoesthemaximumvelocityoccurinaflowthroughacirculartube?（）

答案:InthecenterofthetubeLaplace'sequationgovernswhattypeofflow?()

答案:PotentialflowAnexternaleffectisusedtodenoteanyvariablethatproducesortendstoproducewhat?()

答案:changeinthesystemStreamwiseaccelerationistheproductoftherateofchangeofspeedwithdistancealongthestreamline,,andwhatelse?（）。

答案:thespeedHowisflowaroundahalfbodyobtained?()

答案:ByaddingasourcetoauniformflowWhyarepotentialflowsolutionsalwaysapproximatesolutions?()

答案:Becausethefluidisassumedtobefrictionless.Achangeinfluidvelocitythatresultsinachangeintheelevationofthehydraulicgradelineisdueto:（）。

答案:Changeinpipediameter____representsaflowinwhichthestreamlinesformconcentriccircles.()

答案:AvortexUnitsof____areusedtoquantifytheamountofheadinvolved.()

答案:lengthA2-in.diametershaftissupportedbytwosleeves,eachoflength=2in.Theinternaldiameterofthesleevesis2.1in.Theradialspacebetweentheshaftandthesleevesisfilledwithanoilofviscosity=8×10-3lb-s/ft2.Iftheshaftisrotatedataspeedof600rpm,theviscoustorque(ft-lb)ontheshaftismostnearly（）。

答案:0.15Theforceamplificationcanberealizedbyincreasingtheactingarea.TrueorFalse?（）

答案:對Thepressureamplificationcanberealizedbyincreasingtheactingarea.

（）

答案:錯Howtoreducehydraulicshock?（）。

答案:shortenthelengthofthepipelineasfaraspossible;Extendthetimeofvalveclosing;Increasethediameterofthepipeline;LimitpipelineflowrateWhatismostlikelytobethemaindrivingforceinpipeflow?（）。

答案:ApressuregradientSteady,fullydevelopedpipeflowexperiencesno____.（）。

答案:AccelerationInthecaseoffullydevelopedpipeflow,____.（）。

答案:thevelocityprofileisthesameatanycrosssectionofthepipe.Thenatureofpipeflowis____.（）。

答案:stronglydependentonwhethertheflowislaminarorturbulentDimensionalanalysisisthewhentheresultsofanequationwillbewhatinrelationtothesystemofunitschosen.（）。

答案:IndependentTherequirednumberofpitermsiswhatcomparedtothenumberoforiginalvariables?（）。

答案:fewerthanWhenusingtherepeatingvariablesmethod,thenumberofrepeatingvariablesthatareselectedshouldbewhatcomparedtothenumberofreferencedimensions?（）。

答案:equaltoThedimensionsofthevariableontheleftsideoftheequationmustbe____thedimensionsofanytermthatstandsbyitselfontherightsideoftheequalsign.（）。

答案:equaltoHowdoesvorticityrelatetotherotationvector?（）。

答案:TaylorForirrotationalflow,thevorticityiszero.TrueorFalse?（）

答案:對Howistheaccelerationofaparticledescribed?（）。

答案:Byusingthematerialderivative.TheBernoulliequationcanbewrittenintermsofheightscalledwhat?（）。

答案:headsAfixedcoordinatesystemisnon-inertial.TrueorFalse?（）

答案:錯WhenusingNewton'ssecondlawappliedacrossstreamlinesandtheBernoulliequationitisimportanttobesure____.（）。

答案:thatalloftheassumptionsarenotviolatedAccordingtothesignconvention,massflowrateoutofthecontrolvolumeisnegativeandthemassflowrateinispositive.TrueorFalse?（）

答案:錯Ifaflowisunsteady,its____maychangewithtimeatagivenlocation.（）。

答案:AlloftheaboveIftheflowissteady,therecanbechangesinvelocityatdifferentlocationsintheflowfield,TrueorFalse?（）

答案:對Forabodypartiallysubmergedinafluidandatequilibrium,whichofthefollowingisatruestatement?（）。

答案:TheweightofthebodyisequaltotheweightofthevolumeoffluiddisplacedAninclined-tubemanometerisbeingusedasshowntomeasurethepressureinapressurizedtank.Thetankispartiallyfilledtoadepthof20cmwithafluidofspecificgravity=0.78.Thespecificgravityofthemanometricgagefluidis3.5.Thegagepressureintheheadspace(kPa)whenh=8cmismostnearly