搜索
Chapter1IntroductiontoThermalScience第一章热科学基础Acousticflowmeter声波流量计Corrugatedfin波状散热片Adiabatic[]绝热的Crossproduct矢量积Aerodynamics空气动力学Denominator分母Affiliation联系Developedflow充分发展流Airfoil机翼，螺旋桨Diffusion扩散Alternative替代燃料Dopplereffect多普勒效应Anemometer风速计Double-pipeheatexchanger套管式换热器Angularspeed角速度Drysaturatedvapor干饱和蒸汽Areadensity表面密度Electrode电极Baffle挡板Electrolyte电解，电解液Bifurcation分形Electrostatic静电的Blackbody黑体Emissivity发射率Blade浆叶，叶片Equilibrium平衡Boiler锅炉Fluidmechanics流体力学Boundarylayer边界层Forcedconvection强制对流CarnotCycle卡诺循环Freeconvection自然对流Cartesiancoordinates笛卡尔坐标系Frictionloss摩擦损失CelsiusDegree摄氏度Glassceramic微晶玻璃，玻璃陶瓷Compactheatexchanger紧凑式换热器Heatengine热机Composition成分，合成物Heatpump热泵Compressedliquid压缩液体Hydrofoil水翼Compressibility可压缩性，压缩率Hypersonicspeed高超音速Condensation凝结Infinitesimal无穷小的Condenser冷凝器Inflating/deflating充气/压缩Conduction导热Internalcombustionengine内燃机Controlvolume控制体Isentropic等熵的Convection对流Isobaric等压的Coriolis-accelarationflowmeter科氏加速流量计Isolatedsystem孤立体系的Isometric等容的Rough-walltube粗糙管Isothermal等温的Saturation饱和Kinematicviscosity运动黏度Shearstress剪切力、切应力Laminar层流Shell-and-tubeheatexchanger管壳式换热器Manuscript手稿，原稿Specificvolume比容Moisture湿度，水分Steady稳态的，定常的Molecule(化学)分子Stiflingengine斯特林机Moltenpolymer熔融聚合物Strainrate变形速度，应变率1Muti-disciplinary多学科的Streamline流线NewtonianFluid牛顿流体Strut支撑，支柱Nominaltemperaturegradient法向温度梯度Subcooledliquid过冷液体Numerator（数学）分子Superheatedvapor过热蒸汽Parallelflow平行流动，并流Surrounding环境，外界Pathline迹线Thermalconductivity热传导率Phasechange相变Thermalefficiency热效率Planeflow平面流，二元流Thermodynamics热力学Plateandflameheatexchanger板式换热器Torsional扭力的，扭转的Polymersolution胶浆Trailingedge机翼后缘、尾缘Proof校样Transmitter传送装置、发送器Propeller螺旋桨，推进器Turbinemeter涡轮流量计Pump泵Turbulent湍流的Qulity干度Ultrosonic超声波的Qusi-equilibrium准平衡、准静态Uniformflow均匀刘Radiation辐射Vacuum真空RankinCycle朗肯循环Viewfactor角系数Regenerativeheatexchanger蓄热/再生式换热器Viscous黏性的Reservoir水库，蓄水池Cortexshedding漩涡脱落Reversible可逆的Waterfaucet水龙头，水嘴Rotameter转子流量计AbbreviationBiBiotnumber比澳数NPSH汽蚀余量CFD计算流体力学NTU传热单元数CHF临界热流量Nu努谢尔特数COP制冷系数PE势能Eu欧拉数Pr普朗特数Fo富立叶数Ra瑞利数Fr弗劳德数Re雷诺数Gr格拉晓夫数Sc施密特数KE动能St斯坦顿数，斯特劳哈数LMTD对数平均温差We韦伯数1.1FundamentalofEngineeringThermodynamics1.1工程热力学基础Thermodynamicsisascienceinwhichthestorage,transformationandtransferofenergyarestudied.Energyisstoredasinternalenergy(associatedwithtemperature),kineticenergy(dutomotion),potentialenergy(duetoelevation)andchemicalenergy(duetochemicalcomposition);itistransformedfromoneoftheseformstoanother;anditistransferredacrossaboundaryaseitherheatorwork.2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。Inthermodynamics,wewillderiveequationsthatrelatethetransformationsandtransfersofenergytopropertiessuchastemperature,pressureanddensity.Substancesandtheirproperties,thus,becomeveryimportantinthermodynamics.Manyofourequationswillbebasedonexperimentalobservationsthathavebeenorganizedintomathematicalstatementsorlaws,thefirstandsecondlawsofthermodynamicsaremostwidelyused.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。1.1.1Thermodynamicsystemandcontrolvolume1.1.1热力系统和控制体Athermodynamicsystemisafixedquantityofmattercontainedwithinsomeenclosure.Thesurfaceisusuallyanobviousone(likethatsurroundingthegasinthecylinder).However,itmaybeanimaginedboundary(likethedeformingboundaryofacertainamountofmassasitflowsthroughapump).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）。Allmatterandspaceexternaltoasystemiscollectivelycalleditssurroundings.Thermodynamicsisconcernedwiththeinteractionofasystemanditssurroundings,oronesysteminteractingwithanother.Asysteminteractswithitssurroundingsbytransferringenergyacrossitsboundary.Nomaterialcrossestheboundaryofasystem.Ifthesystemdoesnotexchangeenergywiththesurroundings,itisanisolatedsystem.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。Inmanycases,ananalysisissimplifiedifattentionisfocusedonaparticularvolumeinspaceintowhich,orfromwhich,asubstanceflows.Suchavolumeisacontrolvolume.Apump,aturbine,andaninflatingordeflatingballoonareexamplesofcontrolvolume.Thesurfacethatcompletelysurroundsthecontrolvolumeiscalledacontrolsurface.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3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,wemustchoose,inaparticularproblem,whetherasystemistobeconsideredorwhetheracontrolvolumeismoreuseful.Ifthereismassfluxacrossaboundary,thenacontrolvolumeisrequired;otherwise,asystemisidentified.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，则应选取系统作为研究对象。1.1.2Equilibrium,processandcycle平衡、过程和循环Whenthetemperatureofasystemisreferredto,itisassumedthatallpointsofthesystemhavethesame,oressentiallythesametemperature.Whenthepropertiesareconstantfrompointtopointandwhenthereisnotendencyforchangewithtime,aconditionofthermodynamicequilibriumexists.Ifthetemperature,say,issuddenlyincreasedatsomepartofthesystemboundary,spontaneousredistributionisassumedtooccuruntilallpartsof