流体力学(英文)课件.ppt

1、2022-12-151 2022-12-152Contents Teaching Contents In Classroom Experimental Projects In Teaching LabTotal hours:54Classroom teaching hours:48Practice hours:62022-12-153Teaching Contents(1)Part A(Total hours:36)nA1 Introduction (4 hours)nA2 Fluid statics (6 hours)nA3 Fluid kinematics (6 hours)nA4 Flu

2、id 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)FundamentalFundamental2022-12-154Part B(Total hours:8)lB1 Stream functions and potential functions,frictionless irr

3、otational 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)Te

4、aching Contents(2)Extended contentsExtended contentsFundamentalFundamental2022-12-155Part 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 examp

5、le,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)2022-12-156Experimental Projects(1)In-class (Required)(Total hours:6)nE1 Hydrostatics (1 hour)nE2 Velocity m

6、easurement 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)2022-12-157Experimental Projects(2)After-class (Total hours:6-8

7、)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 Demonstrat

8、ing 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)2022-12-158TextbookFrank M.White.Fluid Mechanics.McGraw Hill Higher Education,7t h Revised edition,2010.22022

9、-12-159ReferencesuE.John Finnemore,Joseph B.Franzini.Fluid Mechanics with Engineering Applications.McGraw-Hill Higher Education,10t h Revised edition,2001.102022-12-1510Referencesu J i n X i a o h o n g,L i Yuanhui.Fluid Mechanics(bilingual Teaching).Beijing:China Power Press,2011.92022-12-1511 5%at

10、tendance 10%homework 10%required experiments 5%optional experiments 70%final examGrades2022-12-1512 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!Fluid can b

11、e found almost everywhere on the earth!2022-12-1513Overview 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

12、 the course History of Fluid MechanicsThe following aspects will be discussed2022-12-1514The 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

13、in motion of that fluid.The fluid moves and deforms continuously as long as the shear is applied.Introduction2022-12-1515Is it has afixed volume？Can it form a free surface？Is it easy to be compressed？Fluidgasnonoyesliquidyesyesno FluidSolidyesnoThe primary physical property of fluid2022-12-1516 Flui

14、d 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

15、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)2022-12-1517Water and air are researched mostly in fluid mechanics.Besides these,fluid also includes vapor as work medium i

16、n 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

17、,ship,runner,etc.Types of boundary2022-12-1518 MechanicsResearch object The carrier of mechanical problemsFluid MechanicsFluidLiquidWaterMechanicsThree conservation lawsHydraulicsIntroductionLiquid is the main research object;Mainly focus on engineering applications;Suitable for students in Hydrauli

18、c Eng.,Civil Eng.The nature of the subject of Fluid MechanicsConservation of mass,momentum and energy2022-12-1519 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 depar

19、tments,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 a

20、nd mining,biology and sea,war industry and nuclear energy,machine building,mechanical engineering,etc.Tasks of Fluid MechanicsIntroductionEngineering fields and disciplines relative to Fluid Mechanics2022-12-1520Vortex created by the passage of an Vortex created by the passage of an aircraft wing,re

21、vealed by coloured smokeaircraft wing,revealed by coloured smokeTurbulence Turbulence in the tip in the tip vortex from vortex from an airplane an airplane wingwingEngineering fields relative to Fluid Mechanics2022-12-1521aviationaviationspaceflightspaceflightnavigationnavigationRocket Rocket launch

22、inglaunchingfountainfountain2022-12-1522Axial-flow fan¢rifugal pumpAxial-flow fan¢rifugal pumpfanfanpumppumpimpellerimpeller2022-12-1523Multi-stage axial-flow compressor modelMulti-stage axial-flow compressor modelCompressorCompressor2022-12-1524Water turbine and electrical generator cut-awa

23、y viewWater turbine and electrical generator cut-away view Kaplan turbineKaplan turbine runner and bladerunner and bladehydropowerhydropower2022-12-1525Model plane tested in a wind tunnelModel plane tested in a wind tunnel Car wind tunnel test Car wind tunnel test Air flow past an aerofoilAir flow p

24、ast an aerofoilCooling fan Cooling fan 2022-12-1526The Three Gorges Dam photographed by satellite of the United StatesHydraulicEngineeringwater conservancy projectDujiangyanDujiangyancomprehensive engng2022-12-1527Typhoon Tornado:A rotating column of air usually accompanied by a funnel-shaped downwa

25、rd 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.Tornado2022-12-1528vortex formed in the vortex formed in

26、 the rear of a high-speed rear of a high-speed traintrainboiling mud near a boiling mud near a Volcanic craterVolcanic craterTornadoTornado2022-12-1529vortices in atmosphere Hurricane 2022-12-1530WeatherCFDsupercomputer2022-12-1531Dew and drop2022-12-1532Surface tensionSurface tensionsoap bubble soa

27、p bubble water-drop water-drop 2022-12-1533volleyballfootballtennisswimmingrowingdiscus throwgolf ballracecar racingjavelintable tennisbadminton2022-12-1534Golf ball with smooth&rough surface,Which is better？Question 2022-12-1535 Golf originated in Scotland in the 15th Century.It was thought in the

28、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 t

29、heory 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.2022-12-1536wake zonewake zonewake zonewake zone2022-12-1537Disci

30、plines Relative to Fluid MechanicsDisciplines 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)

31、Hydrology Hydrostatics Fluid Statics Hydrodynamics Fluid Dynamics Electrohydrodynamics Magnetohydrodynamics Rheology Quantum hydrodynamics2022-12-1538Fluid mechanics has three study approaches.The first one is a theoretical approach.Which analyzes the primary and lesser factor of the question,abstra

32、cts 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 answercalculus,field theor

33、yexact solutiontheoretical analysistheoretical analysis2022-12-1539Study 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 experimen

34、t results according to a certain method.experimental studyexperimental studymodel experiments observation&measurement convert to prototype similarity theoryexperimental datasimilar model2022-12-1540Marvellous phenomena of Marvellous phenomena of flowflowFluid flow past a cylinder Cats eye phenomenon

35、Re numberFluid flow past a spherical bodyboundary layer separation wake zonewake zoneincomingincoming flow flow 2022-12-1541Study 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,inpu

36、ts the data by program and calculates the numerical solution with computer.numerical calculationnumerical calculationmathematical model numerical model numerical solution discretizedequationsgoverning equationsapproximate solutionBoundary conditions&initial conditions computercomputer2022-12-1542Kar

37、man vortex street due to air flows past a cylinderCFDCFDVortex 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.2022-12-1543Simulation of Simulation of

38、 Karman vortexKarman vortexCFDCFDFluid flows past a 2D body2022-12-1544Velocity&pressure distributions in the flow passage of a centrifugal fanCentrifugal fanCentrifugal fanCFDCFD2022-12-1545Numerical simulation with CFDNumerical simulation with CFDPumpCFDCFDmodelpressurevelocity2022-12-1546Air-soli

39、d couplingAir-solid couplingfluid structure fluid structure interaction,interaction,FSIFSICFDCFDDisplacementTotal deformationStressEquivalent stress2022-12-1547 The three approaches have advantages and disadvantages.Only supplement each other can they advance the development of fluid mechanics.Moder

40、n fluid mechanics has band the three approaches together organically and promote the development of fluid mechanics quickly.Study Approaches of Fluid Mechanics(4)2022-12-1548Advantages Disadvantages Theoretical Theoretical analysisanalysisl Exact(analytical)solution can be obtained.l Flow mechanism

41、can be revealed.l Limited to basic assumptions.l Analytical solutions can be obtained only in a few cases.Experimental Experimental studystudyModel Model experimentexperimentl Flow parameters can be measured directly.l Empirical relations can be found.l High cost.l High measurement technique is requ

42、ired.l Uneasy to change the conditions.l Affected by scale effects.Numerical Numerical calculationcalculationl 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 er

43、ror is exist.2022-12-1549Importance(position)of the course Fundamental coursesFundamental courses Basic specialty courseBasic specialty course Relative professional coursesRelative professional coursesIntroductionbridgebridge2022-12-1550The first contribution to the come into being of the subject of

44、 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 Mech

45、anics(1)Introductionl Questions of projectiles movement in fluid was put forward.The first period：before the 20th century BC.2022-12-1551Introductionl Archimedes fix quantity theory of buoyancy;l Maliaut the balance to measure the resistance of moving object;l Pascal the basic relation formula of hy

46、drostatics.History of Fluid Mechanics(2)The second period：from the 20th B.C to late stage of the 17th century A.D.2022-12-1552Introductionl 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

47、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)2022-12-1553 The

48、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)2022-12-1554The endThe endThank you!Thank you!感谢亲观看此幻灯片，此课件部分内容来源于网络，如有侵权请及时联系我们删除，谢谢配合！