《E气体动理论》PPT课件

foundations of Gas kinetics and thermodynamics
1 研究对象
热现象及其规律 物质的热运动和热运动与 其它形式的运动之间相互 转化所遵循的规律
热现象：
组成宏观物体的大量微观 粒子热运动的集体表现 凡是与温度有关的物理现 象都是热现象. 实例: 物体受热温度升高,体积膨 胀,冰受热融化为水等
Introduction
In our study of dynamics, we developed methods to calculate energy. An object have kinetic energy, gravitational potential energy, or elastic potential energy. To calculate the total energy of a collection of objects, we would simply add up the contributions made by each object. However, many physical system contain an impossibly large number of separate object. For instance, a jug of water contains an enormous number of water molecules, and we can hardly calculate the energy of the water by adding up the contributions from each molecule. What can we say about the energy of such a system and energy exchanges that occur when it interacts with other systems?
§1 Equilibrium state Equation of state
1 Equilibrium state 平衡状态
(1) Equilibrium state 平衡状态 The state that macroscopic characteristics do not change with time without external action (influence) 无外界影响时宏观性质不随时间变化的状态 Notes A B Without external action (influence): Neither doing work nor heat transfer Macroscopic characteristics do not change with time thermodynamical equilibrium – 热动平衡 (2) State parameters 状态参量 V P T Volume 体积V Pressure 压强P Temperature 温度T
热运动：
组成宏观物体的大量微观 粒子(分子、原子)的一种 热运动是热现象的微观实质 永不停息的无规则的运动。 热现象是热运动的宏观表现
2 研究方法
Gas kinetics Thermodynamics 热力学： 气体动理论： 以物质的分子、原子结构 不涉及物质的微观结构， 概念和分子热运动概念为 根据由观察和实验总结得 出的热力学定律，从能量 基础, 将微观运动和宏观 运动相联系,应用统计的方 观点出发，分析研究在物 法,解释并揭示物质宏观热 质状态变化过程中有关热 功转化的关系和条件 现象及其有关规律的本质, 确立宏观量和微观量之间 (1) 就整体而言, 在一定状态 的关系系。 下,物质具有一定的能量; (1) 热运动 (2) 从一个状态过度到另一 (2) 微观量，宏观量 个状态,遵从一定规律 (3) 统计规律
In following chapters, we consider these questions. In chapter 18, first, we seek to do so using only macroscopic physical properties; by this we mean measurable properties of bulk system that take no heed of its microscopic constituents. Then, we want to find the relationship between macroscopic and microscopic physical quantities. In chapter 19, we shall concentrate on the first and second laws of thermodynamics. The first law of thermo-dynamics expresses the relationship more formally by explicitly introducing a heat flow term into the energy conservation. This clarification of energy conservation, which was one of the great triumphs of nineteenth-century physics, arose almost by consensus from the work and thoughts of many leading scientists of the time.
Chapter 18
Gas kinetics
§1 Equilibrium state Equation of state §2 Pressure formula for ideal gas §3 Temperature and Energy §4 Theorem of equipartition of energy The internal energy of idea gas §5 Maxwell speed distribution law §6 Molecular mean collision frequency Mean free path §7 Transport phenomena in gas §8 Application