文档介绍：Chapter 3
Fluid Mechanics
1
第三章流体动力学基础
2
Chapter 3 Basis of Fluid Dynamics
§3–4 Continuity Equation
§3–1 Preface
§3–2 Methods to Describe Fluid Motion
§3–3 Basic Concepts of Fluid Motion
§3–5 Motion Differential Equation of Ideal Fluid
§3–6 Bernoulli Equation and Its Application
§3–7 System and Control Volume
§3–8 Momentum Equation
§3–9 Moment of Momentum Equation
Exercises of Chapter 3
3
第三章流体动力学基础
§3–4 连续方程式
§3–1 引言
§3–2 描述流体运动的方法
§3–3 流体运动的基本概念
§3–5 理想流体的运动微分方程
§3–6 伯努利方程及其应用
§3–7 系统与控制体
§3–8 动量方程
§3–9 动量矩方程
第三章习题
4
Chapter 3 Basis of Fluid Dynamics
§3-1 Preface
Basis of Fluid Dynamics
The backgrounds, fundamentals and fundamental equations of fluid dynamics all have certain relations with each part of engineering fluid mechanics, so this chapter is the emphases in the whole lessons.
5
第三章流体动力学基础
§3-1 引言
流体动力学基础
流体动力学的基础知识,基本原理和基本方程与工程流体力学的各部分均有一定的关联,因而本章是整个课程的重点。
6
§3-2 Methods to Describe the Fluid Motion
Methods to describe the fluid motion :
1. Lagrange’s method
Definition:
Lagrange’s method is to consider the fluid particles as research objects and to research the motion course of each particle , and then gain the ic regulation of the whole fluid through synthesizing motion instances of all being researched objects . The essential of lagrangian method is a method of particle coordinates.
Basis of Fluid Dynamics
7
§3-2 描述流体运动的方法
描述流体运动的方法:
一、拉格朗日法
定义:
把流体质点作为研究对象,研究各质点的运动历程,然后通过综合所有被研究流体质点的运动情况来获得整个流体运动的规律,这种方法叫做拉格朗日法。实质是一种质点系法。
流体动力学基础
8
when we use lagrange’s method to describe the fluid motion the position coordinates of motion particles are not independent variables but functions of original coordinate a, b, c and time variable t, that is
(3—1)
In this formula , a ,b ,c and t are all called lagrangian variables. Different particles have different original coordinates.
Difficulties will be met when using lagrange’s method to analyze fluid motion on math except for fewer instances (such as researching