[工学]流体力学英文课件chap.pptx

Overview of Fluid Mechanics 创作者：时间：2024年X月目录第第1 1章章IntroductionIntroduction第第2 2章章FluidPropertiesFluidProperties第第3 3章章FluidStaticsFluidStatics第第4 4章章FluidKinematicsFluidKinematics第第5 5章章FluidDynamicsFluidDynamics第第6 6章章ComputationalFluidDynamicsComputationalFluidDynamics第第7 7章章ConclusionConclusion 0101第1章 Introduction Importance Importance in in EngineeringEngineeringFluid mechanics plays Fluid mechanics plays a crucial role in a crucial role in various engineering various engineering disciplines such as disciplines such as aerospace,civil,and aerospace,civil,and mechanical mechanical engineering.engineering.Understanding fluid Understanding fluid behavior is essential behavior is essential for designing efficient for designing efficient systems and systems and structures.structures.DefinitionofTermsResistancetoflowViscosityForceperunitareaPressureSpeedofflowVelocityTypesofFlowUniformflowrateSteadyFlowChaoticandirregularflowTurbulentFlowSmoothandorderlyflowLaminarFlow BernoullisEquation0103ContinuityEquation02Navier-StokesEquationsEnvironmentalEnvironmentalPollutioncontrolPollutioncontrolWatertreatmentWatertreatmentBiomedicalBiomedicalBloodflowdynamicsBloodflowdynamicsRespiratorysystemRespiratorysystemEnergyEnergyHydropowergenerationHydropowergenerationWindturbinesWindturbinesApplications in Various IndustriesAerospaceAerospaceAerodynamicsAerodynamicsPropulsionsystemsPropulsionsystemsFuture Developments in the FieldThefieldoffluidmechanicsiscontinuouslyevolvingwithadvancementsincomputationalfluiddynamicsandexperimentaltechniques.Futuredevelopmentsmayincludemoreaccuratesimulations,enhancedpredictivemodels,andinnovativeapplicationsinemergingtechnologies.0202第2章 Fluid Properties Definition and classification of fluidsFluidsaresubstancesthatdeformcontinuouslyunderappliedshearstress,exhibitingthepropertyofflow.Theycanbeclassifiedasliquidsorgasesbasedontheirbehavior.Liquidshaveadefinitevolumeandtaketheshapeoftheircontainer,whilegaseshaveneitheradefinitevolumenorshape.Mass per unit volume of a substanceDensity0103Ratio of the density of a substance to thedensityofareferencesubstanceSpecificgravity02WeightperunitvolumeofasubstanceSpecificweightSignificanceSignificanceImpactstheflowbehaviorImpactstheflowbehavioroffluidsoffluidsDifferentiatesbetweenDifferentiatesbetweenliquidsandgasesbasedonliquidsandgasesbasedontheirviscositytheirviscosity Viscosity and its significanceViscosityViscosityAmeasureofafluidsAmeasureofafluidsresistancetodeformationresistancetodeformationundershearstressundershearstressSurface Surface tension and tension and capillaritycapillaritySurface tension is the Surface tension is the tendency of a liquid tendency of a liquid surface to shrink into surface to shrink into the minimum surface the minimum surface area possible.area possible.Capillarity is the Capillarity is the phenomenon of a liquid phenomenon of a liquid rising or falling in a rising or falling in a narrow tube due to narrow tube due to intermolecular forces intermolecular forces between the liquid and between the liquid and the tube.the tube.CompressibilityoffluidsMeasureofafluidsresistancetovolumechangeunderpressureBulkmodulusAbilityofafluidtoreturntoitsoriginalshapeafterdeformationElasticityIncreaseinvolumeofafluidwithtemperature,impactingitsdensityandbehaviorThermalexpansionanditseffectsRealfluidsRealfluidsExhibitviscosityandExhibitviscosityandcompressibility,leadingtocompressibility,leadingtocomplexflowbehaviorcomplexflowbehavior Flow behavior of ideal and real fluidsIdealfluidsIdealfluidsNon-viscousandNon-viscousandincompressible,followingincompressible,followingsimplifiedflowpatternssimplifiedflowpatternsFluids that do not follow Newtons law of viscosityDefinition0103Study of how fluids deform and flow understressRheologicalpropertiesandbehavior02Blood,ketchup,andtoothpasteExamples 0303第三章 Fluid Statics The force per unit area exerted on a surface by a fluidDefinitionofpressure0103Pascal,psi,barPressuremeasurementunits02Absolutepressure,gaugepressure,atmosphericpressureTypesoffluidpressurePascalslawanditsapplicationsHydraulicbrakes,hydraulicliftsHydraulicsystemsPneumatictools,pneumaticpumpsPneumaticsystemsBalancingoffluidcolumnsHydrostaticequilibriumBuoyancy Buoyancy and and Archimedes Archimedes principleprincipleArchimedes principle Archimedes principle states that the buoyant states that the buoyant force acting on an force acting on an object immersed in a object immersed in a fluid is equal to the fluid is equal to the weight of the fluid weight of the fluid displaced by the displaced by the object.This principle is object.This principle is crucial for crucial for understanding understanding buoyancy and the buoyancy and the behavior of objects in behavior of objects in fluids.fluids.StabilitycriteriaStabilitycriteriaPositivestability,neutralPositivestability,neutralstability,negativestabilitystability,negativestabilityFactorsFactorsinfluencinginfluencingstabilitystabilityShapeofbody,centerofShapeofbody,centerofgravity,metacentricheightgravity,metacentricheightStabilityStability analysisanalysismethodsmethodsInitialstabilityassessment,Initialstabilityassessment,stabilityexperimentsstabilityexperimentsStability of submerged and floating bodiesMetacentricMetacentricheightheightDefinitionandimportanceDefinitionandimportanceCalculatingmetacentricCalculatingmetacentricheightheightManometryandpressuremeasurementWorkingprincipleandapplicationsU-tubemanometerMechanismandcalibrationBourdongaugeUseinhigh-pressureapplicationsPiezometerHydrostatic Hydrostatic forces on forces on submerged submerged bodiesbodiesWhen an object is When an object is submerged in a fluid,it submerged in a fluid,it experiences a buoyant experiences a buoyant force and pressure force and pressure forces from the forces from the surrounding fluid.surrounding fluid.Understanding these Understanding these hydrostatic forces is hydrostatic forces is essential for essential for engineering engineering applications such as applications such as designing submerged designing submerged structures and vessels.structures and vessels.AeronauticalAeronauticalengineeringengineeringAerostatics,aircraftdesignAerostatics,aircraftdesignconsiderationsconsiderationsCivilengineeringCivilengineeringHydraulicstructuredesign,Hydraulicstructuredesign,damstabilitydamstabilityMechanicalMechanicalengineeringengineeringFluidpowersystems,pumpFluidpowersystems,pumpdesigndesignApplications of fluid statics in engineeringNavalNavalarchitecturearchitectureStabilityanalysisofshipsStabilityanalysisofshipsBuoyancycalculationsBuoyancycalculationsFluid statics in open and closed systemsFluidstaticsdealswiththebehavioroffluidsatrestandthedistributionofpressureinstaticfluidsystems.Understandingtheprinciplesoffluidstaticsiscrucialforvariousengineeringapplications,includingdesigninghydraulicsystems,calculatinghydrostaticforces,andensuringstabilityinfluidenvironments.Calculating pressure at different depths in a fluidHydrostaticpressureequation0103PressuredistributioninconnectedvesselsHydrostaticparadox02EffectoffluiddensityanddepthonpressurePressurevariationinopentanks 0404第四章 Fluid Kinematics Description Description of fluid of fluid motionmotionFluid motion refers to Fluid motion refers to the movement of a fluid the movement of a fluid in a particular direction in a particular direction or pattern.It can be or pattern.It can be described using described using Lagrangian and Lagrangian and Eulerian approaches,Eulerian approaches,which provide different which provide different perspectives on fluid perspectives on fluid behavior.Streamlines,behavior.Streamlines,streaklines,and streaklines,and pathlines are important pathlines are important concepts in concepts in understanding fluid understanding fluid motion.motion.AccelerationandvorticityoffluidparticlesChangeinvelocityovertimeAccelerationMeasureoflocalfluidrotationVorticityPrincipleofmassconservationinfluiddynamicsConservationofmassContinuityequationanditssignificanceMathematicalexpressionofmassconservationContinuityequationImportanceofmassconservationinfluidflowanalysisSignificanceChangeinfluidshapeovertimeFluiddeformationandstrainrateRepresentation of fluid velocity at different pointsVelocityfield010302Methods to visualize and analyze fluid flowpatternsFlowvisualizationtechniquesFluidFluidkinematicskinematicsinin differentdifferent flowflowregimesregimesComparisonoffluidmotionComparisonoffluidmotioninvariousflowconditionsinvariousflowconditionsKinematicKinematicpropertiespropertiesofofviscousflowsviscousflowsCharacteristicsoffluidCharacteristicsoffluidmotioninviscousflowmotioninviscousflowregimesregimesKinematicKinematicpropertiespropertiesofofinviscidflowsinviscidflowsBehavioroffluidswithBehavioroffluidswithnegligibleviscositynegligibleviscosityApplication of kinematics in fluid dynamicsAnalysisAnalysis ofof fluidfluidflowpatternsflowpatternsStudyoffluidbehaviorinStudyoffluidbehaviorindifferentscenariosdifferentscenarios 0505第五章 Fluid Dynamics Forces Forces acting on a acting on a fluid elementfluid elementWhen analyzing fluid When analyzing fluid dynamics,it is crucial dynamics,it is crucial to understand the to understand the forces acting on a fluid forces acting on a fluid element.These forces element.These forces include pressure,shear include pressure,shear stress,and body force.stress,and body force.By applying Newtons By applying Newtons second law for fluids,second law for fluids,we can determine the we can determine the acceleration of the acceleration of the fluid element.fluid element.Continuity equationConservationofmass0103EnergyequationConservationofenergy02MomentumequationConservationofmomentumFlowaroundimmersedbodiesVisualizingfluidflowpatternsStreamlinesandstreaklinesRelationshipbetweenliftandcirculationKutta-JoukowskitheoremUnderstandingdragforcesDAlembertsparadoxMachnumberMachnumberRatioofflowvelocitytotheRatioofflowvelocitytothespeedofsoundspeedofsoundSonicboomSonicboomLoudnoiseproducedbyLoudnoiseproducedbyshockwavesfromanobjectshockwavesfromanobjecttravelingatoraboveMach1travelingatoraboveMach1IsentropicflowIsentropicflowFlowwithoutanyheatFlowwithoutanyheattransferorfrictionlossestransferorfrictionlossesCompressible flow and its behaviorSpeedofsoundSpeedofsoundDefiningthespeedatwhichDefiningthespeedatwhichdisturbancespropagatedisturbancespropagatethroughthefluidthroughthefluidApplications of fluid dynamics in aerospace engineeringFluiddynamicsplaysacrucialroleinthedesignandanalysisofaircraftandspacecraft.Understandingthebehavioroffluidsundervariousconditionsisessentialforoptimizingaerodynamicperformance,reducingdrag,andenhancinglift.Engineersutilizecomputationalfluiddynamics(CFD)simulationstomodelairflowaroundvehiclesandpredictperformanceaccurately.0606第六章 Computational Fluid Dynamics Introduction Introduction to to ComputationComputational Fluid al Fluid DynamicsDynamicsComputational fluid Computational fluid dynamics(CFD)is a dynamics(CFD)is a branch of fluid branch of fluid mechanics that uses mechanics that uses numerical analysis and numerical analysis and algorithms to solve and algorithms to solve and analyze fluid flow and analyze fluid flow and heat transfer problems.heat transfer problems.It plays a crucial role It plays a crucial role in understanding in understanding complex fluid behavior complex fluid behavior in various engineering in various engineering applications.applications.FiniteDifference,FiniteVolume,andFiniteElementMethodsMethodofapproximatingderivativesusingfinitedifferencesFiniteDifferenceMethodfordiscretizingpartialdifferentialequationsinintegralformFiniteVolumeMethodforsolvingpartialdifferentialequationsbysubdividingthedomainintoelementsFiniteElementStatistical turbulence models based on Reynolds-averaged Navier-Stokes equationsRANSModels0103DetachededdysimulationmodelsforcapturingboundarylayeranddetachedflowregionsDESModels02Large eddy simulation models that resolvelarge-scaleturbulentstructuresLESModelsUnstructuredUnstructuredGridsGridsFlexiblemeshstructuresforFlexiblemeshstructuresforcomplexgeometriescomplexgeometriesSolutionSolutionAlgorithmsAlgorithmsIterativemethodsforsolvingIterativemethodsforsolvingdiscretizedgoverningdiscretizedgoverningequationsequations Grid Generation and Solution AlgorithmsStructuredGridsStructuredGridsRegularmeshpatternsforRegularmeshpatternsforsimplegeometriessimplegeometriesValidation and Verification of CFD SimulationsToensuretheaccuracyandreliabilityofCFDresults,validationcomparessimulationdatawithexperimentalmeasurements,whileverificationassessesthenumericalerrorsandconvergenceofthecomputationalmodel.RigorousvalidationandverificationprocessesareessentialforbuildingconfidenceinCFDsimulations.ApplicationsofCFDinIndustryandResearchDesignandoptimizationofaircraftcomponentsAerospaceSimulationofvehicleaerodynamicsandthermalmanagementAutomotiveAnalysisofwindturbinesandheatexchangersEnergyInteractions between fluid flow and structural deformationCoupledSimulations0103PredictionofstructuralvibrationsinducedbyfluidforcesFlutterAnalysis02AdaptivemeshtechniquesformovingboundariesDynamicMeshDeformationVOFMethodVOFMethodVolumeoffluidapproachVolumeoffluidapproachforfreesurfacesimulationsforfreesurfacesimulationsLagrangianLagrangianModelsModelsParticle-basedtrackingofParticle-basedtrackingofdispersedphasesdispersedphases Multiphase Flow SimulationsEulerian-EulerianEulerian-EulerianModelsModelsSimultaneoustrackingofSimultaneoustrackingofmultiplefluidphasesmultiplefluidphasesFuture Future Trends in Trends in ComputationComputational Fluid al Fluid DynamicsDynamicsThe future of CFD The future of CFD involves advancements involves advancements in high-performance in high-performance computing,machine computing,machine learning,and artificial learning,and artificial intelligence to enhance intelligence to enhance simulation accuracy simulation accuracy and efficiency.and efficiency.Emerging technologies Emerging technologies like GPU acceleration like GPU acceleration and parallel processing and parallel processing will drive innovations will drive innovations in CFD research and in CFD research and development.development.0707第7章 Conclusion Key takeaways from the courseDuringthecourse,wehavelearnedaboutthefundamentalprinciplesoffluidmechanicsanditsapplicationsinengineering.Understandingthebehavioroffluidsiscrucialforvariousindustriesandplaysasignificantroleinthedesignandoperationofmanysystems.Fluid mechanics helps in designing efficient systems that optimize the use of fluids for various applications.Efficientdesign0103Fluid mechanics plays a role in addressingenvironmental concernsrelated tofluid flowandpollutioncontrol.Environmentalimpact02Understandingfluiddynamicsisessentialforensuringthesafetyandreliabilityofengineeringstructures.SafetyconsiderationsFutureprospectsinthefieldAdvancementsinfluidmechanicsresearchofferopportunitiesforinnovativesolutionsinvariousindustries.ResearchopportunitiesEmergingtechnologiesinfluiddynamicscontinuetoexpandthepossibilitiesforengineeringappl