流体力学绪论

1、1 fluid mechanics231、study objects of fluid mechanics2、tasks of fluid mechanics3、study approaches of fluid mechanics4、history of fluid mechanics5、modern teaching research of fluid mechanics6、 modern teaching research of fluid mechanicspreface4一、流体力学的研究对象一、流体力学的研究对象二、流体力学的任务二、流体力学的任务三、流体力学的研究方法三、流体力学

2、的研究方法四、流体力学的发展史四、流体力学的发展史五、流体力学现代教学研究五、流体力学现代教学研究六、流体力学现代教学研究六、流体力学现代教学研究绪绪 论论51、 study objects of fluid mechanics fluid mechanics is an important branch of modern mechanics，its a science that studies fluids balance , mechanical movement laws and the interaction between fluid and the objects around

3、it. it mainly ascertains the distribution of speed and pressure ,energy loss and the interaction force and the moment between fluid and solid. water and air are researched mostly in fluid mechanics. besides these ,fluid also includes vapor as work medium in turbine, lube ,water which mixing with mud

4、 and sand, blood, melting metal and the gas with complicated components coming from burning, plasm under high temperature condition etc.6一、流体力学的研究对象一、流体力学的研究对象 流体力学是近代力学的一大分支，它是研究流体的平衡和机械运动规律以及流体与周围物体之间相互作用的科学，主要是确定流体的速度分布，压强分布与能量损失，以及流体与固体相互间的作用力与作用力矩。 流体力学中研究得最多的流体是水和空气。除水和空气以外流体还包括作为汽轮机工作介质的水蒸汽、润

5、滑油、石油、含泥沙的水体、血液、溶化状态下的金属和燃烧后产生的成分复杂的气体，高温条件下的等离子体等等。7incise the oil well rock with high pressure water stream techniqueexample：8应用高压水射流技术对油井岩石割缝例：9 fluid mechanics is not only an age-old subject, but also a newfashion subject which can be researched on quite widely fields. there are many questions a

6、bout 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 engineer, transporting air and li

7、quid, combustion and explosion, metallurgy and mining, biology and sea, war industry and nuclear energy, machine building, mechanical engineering etc.2、 tasks of fluid mechanics10 流体力学是一门即古老又新兴的学科，存在着极为 广阔的研究天地。 二、流体力学的任务二、流体力学的任务 例如：航空、航天、航海、天文气象、地球物理、水利水电、热能制冷、土建环保、石油化工、气液输送、燃烧爆炸、冶金采矿、生物海洋、军工核能、机械

8、制造、机械工程等等部门都有许多流体力学问题。113、 study approaches of fluid mechanics 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

9、etc), uses mathematical tools to find the general answer about the fluid movement. 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

10、to a certain method. 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 value solution with computer . all these approaches have advantages and disadvantages.

11、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.12三、流体力学的研究方法三、流体力学的研究方法 流体力学有三种研究方法。一种是理论方法，分析问题的主次因素提出适当的假定，抽象出理论模型（如连续介质、理想流体、不可压缩流体等等），

12、适用数学工具寻求流体运动的普遍解。一种是实验方法，将实验流动问题概括为相似的实验模型，在实验中观察现象、测定数据并进而按照一定方法推测实验结果。再一种是计算方法，根据理论分析与实验观测拟订实验方案，通过编制程序输入数据，用计算机算出数值解。 这三种研究方法各有所长，也各有所短。需要相辅相成才有利于推进流体力学的发展。 现代流体力学已将这三种方法有机地结合起来，推动了流体力学的飞速发展。13 the first contribution to the come into being of the subject of fluid mechanics was did by archimedes o

13、f ancient greece. he founded the liquid balance theory include the physical principle of buoyancy and buoyancy stability. he established the basis of the hydrostatics . 4、 history of fluid mechanics the form and development of fluid mechanics is fell into five phases.the first period：before 20 bc. q

14、uestions of projectiles movement in fluid was put forward .the second period：from 20 b.c to late stage of a.d 17. archimedes fix quantity theory of buoyancy; maliaut the balance to measure the resistance of moving object ; pasica the basic relation formula of hydrostatics; the third period ：from lat

15、e stage of a.d 17 to the early days of a.d 20. newton newtons law of viscosity;14 古希腊的阿基米德对流体力学学科的形成作出第一贡献。他建立了包括物理浮力定律和浮力稳定性在内的液体平衡理论。奠定了流体静力学的基础。 四、流体力学的发展史四、流体力学的发展史流体力学的形成和发展大致分为五个时期： 第一时期：公元前二十世纪前。 抛射体在流体中的运动问题的提出。第二时期：公元前二十世纪至十七世纪下叶。 阿基米德浮力的定量理论； 马里奥特测量运动物体阻力的天称； 帕斯卡 流体静力学的基本关系式； 第三时期：十七世纪下叶至二

16、十世纪初叶。 牛 顿 粘性流体的剪应力公式；15the fourth period：from early days of a.d 20 to middle period. prandtl boundary layer theory. lagrange stream function；reynolds reynolds experiment and reynolds equation;navier-stokesdifferential equation of viscous fluid motion;the fifth period：after middle period of a.d 20.

17、the fluid mechanics has begun to research the questions in weather, ocean, petroleum, chemical engineer, energy sources, environmental protection and construction fields etc, and infiltrated with relative contiguous subjects each other and formed many new branches. bernoulli bernoullis law of steady

18、 incompressible fluid; euler describing method of fluid motion and equation set of inviscid fluid motion; 16 伯 努 力 定常不可压缩流体的伯努力定理； 第四时期：二十世纪初叶至中叶。普 朗 特 边界层理论。 欧 拉 流体运动的描述方法和无粘性流体运动的方程组; 拉格朗日 流函数；雷 诺 雷诺实验、雷诺方程式；纳维斯托克斯粘性流体运动微分方程。第五时期：二十世纪中叶以后。 流体力学开始研究气象、海洋、石油、化工、能源、环保和建筑等领域中的流体力学问题，并与有关邻近学科相互渗透，形成许多新

19、分支。175、 how to study fluid mechanics better1.grasping the study method that from common to especial . begin with the mechanical movements general rules of object and grasp the common type of the basic equation set, then analyze the concrete questions according to the concrete conditions. the drived

20、equations are only the simplified application of the basic equations under different conditions. 2.making great efforts to grasp basic knowledge. master the basic principles, basic concepts, basic methods and do exercise repeatedly and understand them profoundly. 3.listening to the teacher carefully

21、 and marking the note properly. listening to the teachers explain and treating method carefully about which you consider are important and difficult . record the thought and method of analyzing the questions about the typical example problems in class. 18五、如何学好流体力学五、如何学好流体力学 1.掌握从一般到特殊的学习方法 从物体机械运动普

22、遍规律出发，掌握一般形式的基本方程组，再根据具体条件分析具体问题，派生方程只是基本方程在不同条件下的简化应用。 2.在掌握“三基”上下功夫 掌握基本原理、基本概念、基本方法，反复训练，深刻理解。 3.认真听课，适当记笔记 对自己认为的重点、难点认真听老师的讲解和处理方法，对典型的课堂例题，应记录分析问题的思路、解题步骤。194. do preparations，attend the lecture with good preparations. do preparations for some more difficult chapters. listening to the teacher

23、explain mostly where you cant understand by yourself. you should read the book with your 70% energy and the most important is to understand it, not to remember it by rote . 5. solution standardization and enhancing to train the basic approaches. youd better copy the topic before do homework so as to reference when you review. insist on solving questions with physical method, define the type of the questions, conclude carefully, cognize the knowledge point in it ,master the thought and method to solve the questions