流体力学(英文)课件.ppt

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1、2022/12/3,1,Fluid Mechanics,2022/12/3,2,Preface,Contents,Teaching Contents In Classroom Experimental Projects In Teaching Lab,Total hours: 54Classroom teaching hours: 48Practice hours: 6,2022/12/3,3,Teaching Contents (1),Part A (Total hours: 36),A1 Introduction (4 hours)A2 Fluid statics (6 hours )A3

2、 Fluid kinematics (6 hours)A4 Fluid dynamics ( 6 hours)A5 Laminar flow, turbulent flow and energy loss (8 hours)A6 Pipe flow and calculation of pipeline (4 hours)A7 Similarity theory and dimensional analysis (2 hours),Fundamental,2022/12/3,4,Part B (Total hours: 8),B1 Stream functions and potential

3、functions, frictionless irrotational flow (4 hours )B2 Boundary layer theory and flow past body (4 hours),Part C (Total hours: 4),C1 Resaerch progress in Fluid Mechancis (1 hour)C2 Modern flow measurement technologies (1 hour)C3 Introduction to numerical simulation of turbulence flow and commercial

4、softwares of CFD (2 hours),Teaching Contents (2),Extended contents,Fundamental,2022/12/3,5,Part 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,

5、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),2022/12/3,6,Experimental Projects (1),In-class (Required) (Total hours: 6),E1 Hydrostatics (1

6、 hour)E2 Velocity measurement with Pitot tube (1 hour)E3 Flow measurement with Venturi tube (1 hour)E4 Verification of Bernoulli equation (1 hour)E5 Reynolds experiment (1 hour)E6 Measurement of friction loss coefficient for circular pipe flow (1 hour),2022/12/3,7,Experimental Projects (2),After-cla

7、ss (Total hours: 6-8),E1 Liquid viscosity measurement (1 hour) (Optional) E2 Demonstrating experiment about flow pattern and streamline (1 hour) (Required) E3 Measurement of local loss coefficient for circular pipe flow (1 hour) (Required) E4 Demonstrating experiment about Siphon principle (1 hour)

8、(Required) E5 Demonstrating experiment about flow around airfoil and cylinder (1 hour) (Required) E6 Demonstrating experiment about vortex formation (1 hour) (Required) E7 Self-designing experiments (1 hour) (Optional),2022/12/3,8,Textbook,Frank M. White. Fluid Mechanics. McGraw Hill Higher Educatio

9、n, 7th Revised edition, 2010.2,2022/12/3,9,References,E. John Finnemore, Joseph B. Franzini. Fluid Mechanics with Engineering Applications. McGraw-Hill Higher Education, 10th Revised edition, 2001.10,2022/12/3,10,References,Jin Xiaohong, Li Yuanhui. Fluid Mechanics (bilingual Teaching). Beijing: Chi

10、na Power Press, 2011.9,2022/12/3,11,5% attendance 10% homework 10% required experiments 5% optional experiments 70% final exam,Grades,2022/12/3,12,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. White,Prelim

11、inary Remarks,Fluid can be found almost everywhere on the earth !,2022/12/3,13,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 Mech

12、anics Importance (position) of the course History of Fluid Mechanics,The following aspects will be discussed:,2022/12/3,14,The 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 fl

13、uid, no matter how small, will result in motion of that fluid. The fluid moves and deforms continuously as long as the shear is applied.,Introduction,2022/12/3,15,Fluidity ？,Fluid,Solid,yes,no,The primary physical property of fluid,2022/12/3,16,Fluid mechanics is an important branch of modern mechan

14、ics，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 pre

15、ssure, energy loss and the interaction force and the moment between fluid and boundary.,Introduction,Study Objects of Fluid Mechanics (1),2022/12/3,17,Water and air are researched mostly in fluid mechanics. Besides these, fluid also includes vapor as work medium in turbine, lube oil, water which mix

16、ing 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),Stationary boundaries：riverbed, pipe wall, building, etc； Moving boundaries：aircraft, ship, runner, etc.,Types

17、of boundary,2022/12/3,18,Mechanics,Research object The carrier of mechanical problems,Fluid Mechanics,Fluid,LiquidWater,Mechanics,Three conservation laws,Hydraulics,Introduction,Liquid is the main research object; Mainly focus on engineering applications; Suitable for students in Hydraulic Eng., Civ

18、il Eng.,The nature of the subject of Fluid Mechanics,Conservation of mass, momentum and energy,2022/12/3,19,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 departmen

19、ts, 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, meta

20、llurgy and mining, biology and sea, war industry and nuclear energy, machine building, mechanical engineering, etc.,Tasks of Fluid Mechanics,Introduction,Engineering fields and disciplines relative to Fluid Mechanics,2022/12/3,20,Vortex created by the passage of an aircraft wing, revealed by coloure

21、d smoke,Turbulence in the tip vortex from an airplane wing,Engineering fields relative to Fluid Mechanics,2022/12/3,21,aviation,spaceflight,navigation,Rocket launching,fountain,2022/12/3,22,Axial-flow fan & centrifugal pump,fan,pump,impeller,2022/12/3,23,Multi-stage axial-flow compressor model,Compr

22、essor,2022/12/3,24,Water turbine and electrical generator cut-away view,Kaplan turbine runner and blade,hydropower,2022/12/3,25,Model plane tested in a wind tunnel,Car wind tunnel test,Air flow past an aerofoil,Cooling fan,2022/12/3,26,The Three Gorges Dam photographed by satellite of the United Sta

23、tes,HydraulicEngineering,water conservancy project,Dujiangyan,comprehensive engng,2022/12/3,27,Typhoon,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 s

24、peeds of up to 500 miles (800 km) per hour.,Typhoon Typhoon: A tropical cyclone occurring in the western Pacific or Indian oceans.,Tornado,2022/12/3,28,vortex formed in the rear of a high-speed train,boiling mud near a Volcanic crater,Tornado,2022/12/3,29,Hurricane “Elena” in the Gulf of Mexico,Weat

25、her nephogram(云图):vortices in atmosphere,Contour of the hurricane Sandy seen from space,Hurricane,2022/12/3,30,Weather nephogram:vortices in atmosphere,Air vortex street over the northern sea of Japan,Weather,CFDsupercomputer,2022/12/3,31,Dew and drop,2022/12/3,32,Surface tension,soap bubble,water-d

26、rop,2022/12/3,33,volleyball,football,tennis,swimming,rowing,discus throw,golf ball,race,car racing,javelin,table tennis,badminton,Most sports are related to Fluid Mechanics,2022/12/3,34,Golf ball with smooth & rough surface, Which is better？,Question,2022/12/3,35,Golf originated in Scotland in the 1

27、5th 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 t

28、o 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.,2022/12/3,36,Early golf

29、 ball,Present-day golf,wake zone,wake zone,2022/12/3,37,Disciplines Relative to Fluid Mechanics,Acoustics (aerodynamic noise) Aerodynamics Aeroelasticity Aeronautics Computational Fluid Dynamics CFDFlow field measurementHemodynamics Hydraulics the physical science and technology of the static and dy

30、namic behavior of fluids) Hydrology Hydrostatics Fluid Statics Hydrodynamics Fluid Dynamics Electrohydrodynamics Magnetohydrodynamics Rheology Quantum hydrodynamics,2022/12/3,38,Fluid mechanics has three study approaches. The first one is a theoretical approach. Which analyzes the primary and lesser

31、 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),Introduction,basic hypotheses,mathematical model,analytical s

32、olution,general answer,mathematical tools: calculus, field theory,exact solution,theoretical analysis,2022/12/3,39,Study 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 an

33、d determines the data and conjectures the experiment results according to a certain method.,experimental study,model experiments,observation & measurement,convert to prototype,similarity theory,experimental data,similar model,2022/12/3,40,Marvellous phenomena of flow,Fluid flow past a cylinder Cats

34、eye phenomenonRe number,Fluid flow past a spherical bodyboundary layer separation,wake zone,incoming flow,2022/12/3,41,Study 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, input

35、s the data by program and calculates the numerical solution with computer.,numerical calculation,mathematical model,numerical model,numerical solution,discretizedequations,governing equations,approximate solution,Boundary conditions & initial conditions,computer,2022/12/3,42,Karman vortex street due

36、 to air flows past a cylinder,CFD,Vortex 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.,2022/12/3,43,Simulation of Karman vortex,CFD,Fluid flows

37、past a 2D body,2022/12/3,44,Velocity & pressure distributions in the flow passage of a centrifugal fan,Centrifugal fan,CFD,2022/12/3,45,Numerical simulation with CFD,Pump,CFD,model,pressure,velocity,2022/12/3,46,Air-solid coupling,fluid structure interaction, FSI,CFD,DisplacementTotal deformation,St

38、ressEquivalent stress,2022/12/3,47,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.

39、,Study Approaches of Fluid Mechanics (4),2022/12/3,48,2022/12/3,49,EXIT,Importance (position) of the course,Mathematics, Mechanics Fundamental courses,Fluid Mechanics Basic specialty course,Subject of Mechanical Engng Relative professional courses,Introduction,bridge,2022/12/3,50,The first contribut

40、ion 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 mechanic

41、s is fell into five phases.,History of Fluid Mechanics (1),Introduction,Questions of projectiles movement in fluid was put forward.,The first period：before the 20th century BC.,2022/12/3,51,Introduction,Archimedes fix quantity theory of buoyancy; Maliaut the balance to measure the resistance of movi

42、ng object; 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.,2022/12/3,52,Introduction,Newton Newtons law of viscosity; Bernoulli Bernoullis law of steady incompressible fluid; Euler describing

43、 a method of fluid motion and equations of inviscid fluid motion; Lagrange stream function; ReynoldsReynolds experiment and Reynolds equation; 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

44、 A.D.,History of Fluid Mechanics (3),2022/12/3,53,The fourth period：from early days of the 20th century A.D to the middle period.,The fluid mechanics has begun to research the questions in weather, ocean, petroleum, chemical engineering, energy sources, environmental protection and construction fiel

45、ds etc, and infiltrated with relative contiguous subjects each other and formed many new branches.,Introduction,Prandtl boundary layer theory.,The fifth period：after middle period of the 20th century A.D.,History of Fluid Mechanics (4),2022/12/3,54,The endThank 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！,