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Fluid Mechanics Fluid Mechanics PrefaceContents Teaching Contents In Classroom Experimental Projects In Teaching LabTotal hours:54Classroom teaching hours:48Practice hours:6PrefaceContents Teaching ConteTeaching Contents(1)Part A(Total hours:36)nA1 Introduction (4 hours)nA2 Fluid statics (6 hours)nA3 Fluid kinematics (6 hours)nA4 Fluid dynamics (6 hours)nA5 Laminar flow,turbulent flow and energy loss (8 hours)nA6 Pipe flow and calculation of pipeline (4 hours)nA7 Similarity theory and dimensional analysis (2 hours)FundamentalTeaching Contents(1)Part A(TPart B(Total hours:8)lB1 Stream functions and potential functions,frictionless irrotational flow (4 hours)lB2 Boundary layer theory and flow past body (4 hours)Part C(Total hours:4)uC1 Resaerch progress in Fluid Mechancis (1 hour)uC2 Modern flow measurement technologies (1 hour)uC3 Introduction to numerical simulation of turbulence flow and commercial softwares of CFD (2 hours)Teaching Contents(2)Extended contentsFundamentalPart B(Total hours:8)B1 StrPart A and Part B are the foundation of Fluid Mechanics,Part C is the extended contents and refer to some practical problems.This course also pays much attention to the prevalence of modern fluid mechanics,for example,the introduction to the theory of turbulence boundary layer and the sketch of computational fluid dynamics(CFD)will help your further applications after your graduation.Teaching Contents(3)Part A and Part B are the founExperimental Projects(1)In-class (Required)(Total hours:6)nE1 Hydrostatics (1 hour)nE2 Velocity measurement with Pitot tube (1 hour)nE3 Flow measurement with Venturi tube (1 hour)nE4 Verification of Bernoulli equation (1 hour)nE5 Reynolds experiment (1 hour)nE6 Measurement of friction loss coefficient for circular pipe flow (1 hour)Experimental Projects(1)In-clExperimental Projects(2)After-class (Total hours:6-8)pE1 Liquid viscosity measurement (1 hour)(Optional)pE2 Demonstrating experiment about flow pattern and streamline (1 hour)(Required)pE3 Measurement of local loss coefficient for circular pipe flow (1 hour)(Required)pE4 Demonstrating experiment about Siphon principle (1 hour)(Required)pE5 Demonstrating experiment about flow around airfoil and cylinder (1 hour)(Required)pE6 Demonstrating experiment about vortex formation (1 hour)(Required)pE7 Self-designing experiments (1 hour)(Optional)Experimental Projects(2)AfteTextbooku Frank M.White.Fluid Mechanics.McGraw Hill Higher Education,7th Revised edition,2010.2Textbook Frank M.White.FluidReferencesuE.John Finnemore,Joseph B.Franzini.Fluid Mechanics with Engineering Applications.McGraw-Hill Higher Education,10th Revised edition,2001.10ReferencesE.John Finnemore,JReferencesu Jin Xiaohong,Li Yuanhui.Fluid Mechanics(bilingual Teaching).Beijing:China Power Press,2011.9References Jin Xiaohong,Li Yu 5%attendance 10%homework 10%required experiments 5%optional experiments 70%final examGrades 5%attendanceGrades Chapter 1 Introduction When you think about it,almost everything on this planet either is a fluid or moves within or near a fluid.Frank M.WhitePreliminary RemarksFluid can be found almost everywhere on the earth!Chapter 1 Introduction Overview of Fluid Mechanics The concept of fluid The primary physical property of fluid Study objects of Fluid Mechanics The nature of the subject of Fluid Mechanics Tasks of Fluid Mechanics Study approaches of Fluid Mechanics Importance(position)of the course History of Fluid MechanicsThe following aspects will be discussed:Overview of Fluid Mechanics TThe concept of a fluid A solid can resist a shear stress by a static deformation.A fluid can not resist a shear stress by a static deformation.Any shear stress applied to a fluid,no matter how small,will result in motion of that fluid.The fluid moves and deforms continuously as long as the shear is applied.IntroductionThe concept of a fluid A solidIs it has afixed volume？Can it form a free surface？Is it easy to be compressed？FluidgasnonoyesliquidyesyesnoyesnoThe primary physical property of fluidIs it has aCan it form a free Fluid mechanics is an important branch of modern mechanics，Its a science that studies fluids balance(Fluid statics),mechanical movement laws(Fluid Kinematics)and the interaction between fluid and the boundaries(Fluid Dynamics),which may be either solid surfaces or interfaces with other fluids.It mainly ascertains the distribution of speed and pressure,energy loss and the interaction force and the moment between fluid and boundary.IntroductionStudy Objects of Fluid Mechanics(1)Fluid mechanics is an importaWater and air are researched mostly in fluid mechanics.Besides these,fluid also includes vapor as work medium in turbine,lube oil,water which mixing with mud and sand,blood,melting metal and the gas with complicated components coming from burning,plasmas under high temperature condition,etc.Study Objects of Fluid Mechanics(2)l Stationary boundaries：riverbed,pipe wall,building,etc；l Moving boundaries：aircraft,ship,runner,etc.Types of boundaryWater and air are researchedResearch object The carrier of mechanical problems Three conservation lawsHydraulicsIntroductionLiquid is the main research object;Mainly focus on engineering applications;Suitable for students in Hydraulic Eng.,Civil Eng.The nature of the subject of Fluid MechanicsConservation of mass,momentum and energy MechanicsResearch object The Fluid mechanics is not only an age-old subject,but also a new fashion subject which can be researched on quite widely fields.There are many questions about fluid mechanics in these departments,such as in aviation,spaceflight,navigation,astronomical weather,physical geography,water conservancy and hydropower,heat energy refrigeration,building construction and environmental protection,petroleum and chemical engineering,transporting air and liquid,combustion and explosion,metallurgy and mining,biology and sea,war industry and nuclear energy,machine building,mechanical engineering,etc.Tasks of Fluid MechanicsIntroductionEngineering fields and disciplines relative to Fluid Mechanics Fluid mechanics is not only Vortex created by the passage of an aircraft wing,revealed by coloured smokeTurbulence in the tip vortex from an airplane wingEngineering fields relative to Fluid MechanicsVortex created by the passage aviationspaceflightnavigationRocket launchingfountainaviationspaceflightnavigationRAxial-flow fan¢rifugal pumpfanpumpimpellerAxial-flow fan¢rifugal pMulti-stage axial-flow compressor modelCompressor Multi-stage axial-flow compresWater turbine and electrical generator cut-away view Kaplan turbine runner and bladehydropowerWater turbine and electrical gModel plane tested in a wind tunnel Car wind tunnel test Air flow past an aerofoilCooling fan Model plane tested in a wind tThe Three Gorges Dam photographed by satellite of the United StatesHydraulicEngineeringwater conservancy projectDujiangyancomprehensive engngThe Three Gorges Dam photograpTyphoon Tornado:A rotating column of air usually accompanied by a funnel-shaped downward extension of a cumulonimbus cloud and having a vortex several hundred yards in diameter whirling destructively at speeds of up to 500 miles(800 km)per hour.Typhoon Typhoon:A tropical cyclone occurring in the western Pacific or Indian oceans.TornadoTyphoon Tornado:A rotating covortex formed in the rear of a high-speed trainboiling mud near a Volcanic craterTornadovortex formed in the rear of aHurricane“Hurricane“ElenaElena”in”in the Gulf of Mexicothe Gulf of Mexico WeatherWeather nephogram nephogram(云图云图云图云图):):vortices in atmosphere Contour of the hurricane Contour of the hurricane SandySandy seen from space seen from space Hurricane Hurricane“Elena”in the Gulf Weather nephogram:Weather nephogram:vortices in atmosphere vortices in atmosphere Air vortex street over the Air vortex street over the northern sea of Japannorthern sea of JapanWeatherCFDsupercomputerWeather nephogram:Air vortex sDew and dropDew and dropSurface tensionsoap bubble water-drop Surface tensionsoap bubble watvolleyballfootballtennisswimmingrowingdiscus throwgolf ballracecar racingjavelintable tennisbadmintonMost sports are related to Fluid MechanicsvolleyballfootballtennisswimmiGolf ball with smooth&rough surface,Which is better？Question Golf ball with smooth&rough Golf originated in Scotland in the 15th Century.It was thought in the early days that the golf ball with smooth surface had small flight resistance,so the ball was made in leather.It was found afterwards that an old ball with many scratches on its surface could fly farther than a new ball with smooth surface.This mystery was not to be solved until the boundary layer theory was established by L.Prandtl in the 20th Century.The present-day golf has a lot of pits on its surface,and the flight distance of a rough surface ball is 5 times farther than a smooth ball when they have the same size and weight.Golf originated in Scotland iEarly golf ballEarly golf ballPresent-day golfPresent-day golfwake zonewake zoneEarly golf ballPresent-day goDisciplines Relative to Fluid MechanicsAcoustics(aerodynamic noise)Aerodynamics Aeroelasticity Aeronautics Computational Fluid Dynamics CFDFlow field measurementHemodynamics Hydraulics the physical science and technology of the static and dynamic behavior of fluids)Hydrology Hydrostatics Fluid Statics Hydrodynamics Fluid Dynamics Electrohydrodynamics Magnetohydrodynamics Rheology Quantum hydrodynamicsDisciplines Relative to Fluid Fluid mechanics has three study approaches.The first one is a theoretical approach.Which analyzes the primary and lesser factor of the question,abstracts theoretical model(such as continuous medium,ideal fluid,incompressible fluid,etc),uses mathematical tools to find the general answer about the fluid movement.Study Approaches of Fluid Mechanics(1)Introductionbasic hypotheses mathematical modelanalytical solutiongeneral answermathematical tools:mathematical tools:calculus,field theoryexact solutiontheoretical analysisFluid mechanics has three studStudy Approaches of Fluid Mechanics(2)The second is an experimental approach.Which summarizes the fluid question by experiment as a similar experiment model,observes the phenomena and determines the data and conjectures the experiment results according to a certain method.experimental studymodel experiments observation&measurement convert to prototype similarity theoryexperimental datasimilar modelStudy Approaches of Fluid MechMarvellous phenomena of flowFluid flow past a cylinder Cats eye phenomenonRe numberFluid flow past a spherical bodyboundary layer separation wake zoneincoming flow Marvellous phenomena of flowFlStudy Approaches of Fluid Mechanics(3)The third is a calculating approach.Which draws out the experiment scheme according to the theory analysis and experiment observation,inputs the data by program and calculates the numerical solution with computer.numerical calculationmathematical model numerical model numerical solution discretizedequationsgoverning equationsapproximate solutionBoundary conditions&initial conditions computerStudy Approaches of Fluid MechKarman vortex street due to air flows past a cylinderCFDVortex shedding behind a circular cylinder.In this animation,the flow on the two sides of the cylinder are shown in different colors,which shows that the vortices are formed from the two sides alternately.Karman vortex street due to aiSimulation of Karman vortexCFDFluid flows past a 2D bodySimulation of Karman vortexCFDVelocity&pressure distributions in the flow passage of a centrifugal fanCentrifugal fanCFDVelocity&pressure distributiNumerical simulation with CFDPumpCFDmodelpressurevelocityNumerical simulation with CFDPAir-solid couplingfluid structure interaction,FSICFDDisplacementTotal deformationStressEquivalent stressAir-solid couplingfluid struct The three approaches have advantages and disadvantages.Only supplement each other can they advance the development of fluid mechanics.Modern fluid mechanics has band the three approaches together organically and promote the development of fluid mechanics quickly.Study Approaches of Fluid Mechanics(4)The three approaches haveAdvantages Disadvantages Theoretical analysisl Exact(analytical)solution can be obtained.l Flow mechanism can be revealed.l Limited to basic assumptions.l Analytical solutions can be obtained only in a few cases.Experimental studyModel experimentl Flow parameters can be measured directly.l Empirical relations can be found.l High cost.l High measurement technique is required.l Uneasy to change the conditions.l Affected by scale effects.Numerical calculationl Can expand the range of theoretical solution.l Low cost.l Easy to change conditions.l Its not affected by scale effects.l Limited to theoretical model and numerical model.l Computational error is exist.Advantages Disadvantages HighEXITImportance(position)of the courseMathematics,MechanicsMathematics,Mechanics Fundamental coursesFluid MechanicsFluid Mechanics Basic specialty course Subject of Mechanical EngngSubject of Mechanical Engng Relative professional coursesIntroductionbridgeEXITImportance(position)of tThe first contribution to the come into being of the subject of fluid mechanics was did by Archimedes of ancient Greece.He founded the liquid balance theory include the physical principle of buoyancy and buoyancy stability.He established the basis of the hydrostatics.The formation and development of fluid mechanics is fell into five phases.History of Fluid Mechanics(1)Introductionl Questions of projectiles movement in fluid was put forward.The first period：before the 20th century BC.The first contribution to the Introductionl Archimedes fix quantity theory of buoyancy;l Maliaut the balance to measure the resistance of moving object;l Pascal the basic relation formula of hydrostatics.History of Fluid Mechanics(2)The second period：from the 20th B.C to late stage of the 17th century A.D.Introduction Archimedes fixIntroductionl Newton Newtons law of viscosity;l Bernoulli Bernoullis law of steady incompressible fluid;l Euler describing a method of fluid motion and equations of inviscid fluid motion;l Lagrange stream function;l ReynoldsReynolds experiment and Reynolds equation;l Navier-Stokes differential equations of viscous fluid motion.The third period：from late stage of the 17th century A.D to the early days of the 20th century A.D.History of Fluid Mechanics(3)Introduction Newton Newton The fourth period：from early days of the 20th century A.D to the middle period.l The fluid mechanics has begun to research the questions in weather,ocean,petroleum,chemical engineering,energy sources,environmental protection and construction fields etc,and infiltrated with relative contiguous subjects each other and formed many new branches.Introductionl Prandtl boundary layer theory.The fifth period：after middle period of the 20th century A.D.History of Fluid Mechanics(4)The fourth period：from early The endThe endThank you!Thank you!The end
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