Chapter 1 Introduction to Thermal Science
第一章 热科学基础
Acoustic flow meter 声波流量计 Adiabatic [Affiliation 联系 Airfoil 机翼，螺旋桨 Alternative 替代燃料 Anemometer 风速计 Angular speed 角速度 Area density 表面密度 Baffle 挡板 Bifurcation 分形 Blackbody 黑体 Blade 浆叶，叶片 Boiler 锅炉
Boundary layer 边界层 Carnot Cycle 卡诺循环
Cartesian coordinates 笛卡尔坐标系 Celsius Degree 摄氏度
Compact heat exchanger 紧凑式换热器 Composition 成分，合成物 Compressed liquid 压缩液体 Compressibility 可压缩性，压缩率 Condensation 凝结 Condenser 冷凝器 Conduction 导热 Control volume 控制体 Convection 对流 速流量计
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]绝热的
Corrugated fin 波状散热片 Cross product 矢量积 Denominator 分母
Developed flow 充分发展流 Diffusion 扩散
Doppler effect 多普勒效应
Double-pipe heat exchanger 套管式换热器
Dry saturated vapor 干饱和蒸汽 Electrode 电极
Electrolyte 电解，电解液 Electrostatic 静电的 Emissivity 发射率 Equilibrium 平衡 Fluid mechanics 流体力学 Forced convection 强制对流 Free convection 自然对流 Friction loss 摩擦损失
Glass ceramic 微晶玻璃，玻璃陶瓷 Heat engine 热机 Heat pump 热泵 Hydrofoil 水翼
Hypersonic speed 高超音速 Infinitesimal 无穷小的 Inflating/deflating 充气/压缩 Internal combustion engine 内燃机 Isentropic 等熵的 Isobaric 等压的
Aerodynamics 空气动力学
Coriolis-accelaration flowmeter 科氏加Isolated system 孤立体系的
Isometric 等容的 Isothermal 等温的
Kinematic viscosity 运动黏度 Laminar 层流
Manuscript 手稿，原稿 Moisture 湿度，水分 Molecule (化学)分子 Molten polymer 熔融聚合物 Muti-disciplinary 多学科的 Newtonian Fluid 牛顿流体 梯度
Numerator （数学）分子 Parallel flow 平行流动，并流 Pathline迹线 Phase change 相变 Plane flow 平面流，二元流 Plate and flame heat exchanger 板式换热器
Polymer solution 胶浆 Proof 校样
Propeller 螺旋桨，推进器 Pump泵 Qulity 干度
Qusi-equilibrium 准平衡、准静态 Radiation 辐射 Rankin Cycle 朗肯循环 Regenerative heat exchanger 蓄热/再生式换热器 Reservoir 水库，蓄水池 Reversible 可逆的 Rotameter 转子流量计
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Rough-wall tube 粗糙管 Saturation 饱和
Shear stress 剪切力、切应力
Shell-and-tube heat exchanger管壳式换热器
Specific volume 比容 Steady 稳态的，定常的 Stifling engine 斯特林机 Strain rate 变形速度，应变率 Streamline 流线 Strut 支撑，支柱
Nominal temperature gradient 法向温度Subcooled liquid过冷液体
Superheated vapor 过热蒸汽 Surrounding 环境，外界 Thermal conductivity 热传导率 Thermal efficiency 热效率 Thermodynamics 热力学 Torsional 扭力的，扭转的 Trailing edge 机翼后缘、尾缘 Transmitter 传送装置、发送器 Turbine meter 涡轮流量计 Turbulent 湍流的 Ultrosonic 超声波的 Uniform flow 均匀刘 Vacuum 真空 View factor 角系数 Viscous 黏性的
Cortex shedding 漩涡脱落 Water faucet 水龙头，水嘴
Bi Biot number 比澳数 CFD 计算流体力学 CHF 临界热流量 COP 制冷系数 Eu 欧拉数 Fo 富立叶数 Fr 弗劳德数 Gr 格拉晓夫数 KE 动能
LMTD对数平均温差
NPSH 汽蚀余量 NTU 传热单元数 Nu 努谢尔特数 PE 势能 Pr 普朗特数 Ra 瑞利数 Re 雷诺数 Sc 施密特数
St 斯坦顿数 ， 斯特劳哈数 We 韦伯数
1.1 Fundamental of Engineering Thermodynamics
1.1 工程热力学基础
Thermodynamics is a science in which the storage, transformation and transfer of energy are studied. Energy is stored as internal energy (associated with temperature), kinetic energy (du to motion), potential energy (due to elevation) and chemical energy (due to chemical composition); it is transformed from one of these forms to another; and it is transferred across a boundary as either heat or work.
热力学是一门研究能量储存、转换及传递的科学。能量以内能（与温度有关）、动能（由物体运动引起）、势能（由高度引起）和化学能（与化学组成相关）的形式储存。不同形式的能量可以相互转化，而且能量在边界上可以以热和功的形式进行传递。
In thermodynamics, we will derive equations that relate the transformations and transfers of energy to properties such as temperature, pressure and density. Substances and their properties, thus, become very important in thermodynamics. Many of our equations will be based on experimental observations that have been organized into mathematical statements or laws, the first and second laws of thermodynamics are most widely used.
在热力学中，我们将推导有关能量转化和传递与物性参数，如温度、压强及密度等关系间的方程。因此，在热力学中，物质及其性质变得非常重要。许多热力学方程都是建立在实验观察的基础之上，而且这些实验观察的结果已被整理成数学表达式或定律的形式。其中，热力学第一定律和第二定律应用最为广泛。
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1.1.1 Thermodynamic system and control volume 1.1.1 热力系统和控制体
A thermodynamic system is a fixed quantity of matter contained within some enclosure. The surface is usually an obvious one (like that surrounding the gas in the cylinder). However, it may be an imagined boundary (like the deforming boundary of a certain amount of mass as it flows through a pump).
热力系统是一包围在某一封闭边界内的具有固定质量的物质。系统边界通常是比较明显的（如气缸内气体的固定边界）。然而，系统边界也可以是假想的（如一定质量的流体流经泵时不断变形的边界）。
All matter and space external to a system is collectively called its surroundings. Thermodynamics is concerned with the interaction of a system and its surroundings, or one system interacting with another. A system interacts with its surroundings by transferring energy across its boundary. No material crosses the boundary of a system. If the system does not exchange energy with the surroundings, it is an isolated system.
系统之外的所有物质和空间统称外界或环境。热力学主要研究系统与外界或系统与系统之间的相互作用。系统通过在边界上进行能量传递，从而与外界进行相互作用，但在边界上没有质量交换。当系统与外界间没有能量交换时，这样的系统称为孤立系统。
In many cases, an analysis is simplified if attention is focused on a particular volume in space into which, or from which, a substance flows. Such a volume is a control volume. A pump, a turbine, and an inflating or deflating balloon are examples of control volume. The surface that completely surrounds the control volume is called a control surface.
在许多情况下，当我们只关心空间中有物质流进或流出的某个特定体积时，分析可以得到简化。这样的特定体积称为控制体。例如泵、透平、充气或放气的气球都是控制体的例子。包含控制体的表面称为控制表面。
Thus, we must choose, in a particular problem, whether a system is to be considered or whether a control volume is more useful. If there is mass flux across a boundary, then a control volume is required; otherwise, a system is identified.
因此，对于具体的问题，我们必须确定是选取系统作为研究对象有利还是选取控制体作为研究对象有利。如果边界上有质量交换，则选取控制体有利；反之，则应选取系统作为
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研究对象。
1.1.2 Equilibrium, process and cycle
平衡、过程和循环
When the temperature of a system is referred to, it is assumed that all points of the system have the same, or essentially the same temperature. When the properties are constant from point to point and when there is no tendency for change with time, a condition of thermodynamic equilibrium exists. If the temperature, say, is suddenly increased at some part of the system boundary, spontaneous redistribution is assumed to occur until all parts of the
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system are at the same temperature.
对于某一参考系统，假设系统内各点温度完全相同。当物质内部各点的特性参数均相同且不随时间变化时，则称系统处于热力学平衡状态。当系统边界某部分的温度突然上升时，则系统内的温度将自发地重新分布，直至处处相同。
When a system changes from one equilibrium state to another, the path of successive sates through which the system passes is called process. If, in the passing one state to the next, the deviation from equilibrium is infinitesimal, a quasi-equilibrium process occurs, and each state in the process may be idealized as an equilibrium state. Quasi-equilibrium processes can approximate many processes, such as the compression and expansion of gases in an internal combustion engine, with no significant loss of accuracy. If the system goes from one equilibrium state to another through a series of non-equilibrium states (as in combustion), a non-equilibrium process occurs.
当系统从一个平衡状态转变为另一个平衡状态时，系统所经历的一系列由中间状态组成的变化历程称为过程。若从一个状态到达另一个状态的过程中，始终无限小地偏离平衡态，则称该过程为准静态过程，可以把其中任一个中间状态看作为平衡状态。准静态过程可近似视为许多过程的叠加结果，而不会显著减小其精确性，例如气体在内燃机内的压缩和膨胀过程。如果系统经历一系列不平衡状态（如燃烧），从一个平衡状态转变为另一个平衡状态，则其过程为非平衡过程。
When a system in a given initial state experiences a series of process and returns to the initial state, the system goes a cycle. At the end of the cycle, the properties of
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