Slide 1Slide 2THERMODYNAMICS AND ENERGYSlide 4Application Areas of ThermodynamicsSlide 6IMPORTANCE OF DIMENSIONS AND UNITSSlide 8Some SI and English UnitsSlide 10Slide 11Unity Conversion RatiosSlide 13Slide 14SYSTEMS AND CONTROL VOLUMESSlide 16Slide 17PROPERTIES OF A SYSTEMContinuumDENSITY AND SPECIFIC GRAVITYSTATE AND EQUILIBRIUMThe State PostulatePROCESSES AND CYCLESSlide 24The Steady-Flow ProcessSlide 26TEMPERATURE AND THE ZEROTH LAW OF THERMODYNAMICSTemperature ScalesSlide 29Slide 30Slide 31PRESSURESlide 33Variation of Pressure with DepthSlide 35Slide 36Slide 37PRESSURE MEASUREMENT DEVICESSlide 39The ManometerSlide 41Other Pressure Measurement DevicesSlide 43PROBLEM-SOLVING TECHNIQUESlide 45Slide 46Slide 47Slide 48SummaryCHAPTER 1INTRODUCTION AND BASIC CONCEPTSLecture slides byMehmet KanogluCopyright © The McGraw-Hill Education. Permission required for reproduction or display.Thermodynamics: An Engineering Approach 8th EditionYunus A. Çengel, Michael A. BolesMcGraw-Hill, 20152Objectives•Identify the unique vocabulary associated with thermodynamics through the precise definition of basic concepts to form a sound foundation for the development of the principles of thermodynamics.•Review the metric SI and the English unit systems.•Explain the basic concepts of thermodynamics such as system, state, state postulate, equilibrium, process, and cycle.•Review concepts of temperature, temperature scales, pressure, and absolute and gage pressure.•Introduce an intuitive systematic problem-solving technique.3THERMODYNAMICS AND ENERGY•Thermodynamics: The science of energy. •Energy: The ability to cause changes.•The name thermodynamics stems from the Greek words therme (heat) and dynamis (power).•Conservation of energy principle: During an interaction, energy can change from one form to another but the total amount of energy remains constant. •Energy cannot be created or destroyed.•The first law of thermodynamics: An expression of the conservation of energy principle.•The first law asserts that energy is a thermodynamic property.4•The second law of thermodynamics: It asserts that energy has quality as well as quantity, and actual processes occur in the direction of decreasing quality of energy.•Classical thermodynamics: A macroscopic approach to the study of thermodynamics that does not require a knowledge of the behavior of individual particles. •It provides a direct and easy way to the solution of engineering problems and it is used in this text. •Statistical thermodynamics: A microscopic approach, based on the average behavior of large groups of individual particles.•It is used in this text only in the supporting role.5Application Areas of ThermodynamicsAll activities in nature involve some interaction between energy and matter; thus, it is hard to imagine an area that does not relate to thermodynamics in some manner.67IMPORTANCE OF DIMENSIONS AND UNITS•Any physical quantity can be characterized by dimensions. •The magnitudes assigned to the dimensions are called units. •Some basic dimensions such as mass m, length L, time t, and temperature T are selected as primary or fundamental dimensions, while others such as velocity V, energy E, and volume V are expressed in terms of the primary dimensions and are called secondary dimensions, or derived dimensions.•Metric SI system: A simple and logical system based on a decimal relationship between the various units.•English system: It has no apparent systematic numerical base, and various units in this system are related to each other rather arbitrarily.89Some SI and English UnitsWork = Force  Distance1 J = 1 N∙m1 cal = 4.1868 J1 Btu = 1.0551 kJ10W weightm massg gravitational acceleration11Specific weight : The weight of a unit volume of a substance.12Unity Conversion RatiosAll nonprimary units (secondary units) can be formed by combinations of primary units. Force units, for example, can be expressed asThey can also be expressed more conveniently as unity conversion ratios asUnity conversion ratios are identically equal to 1 and are unitless, and thus such ratios (or their inverses) can be inserted conveniently into any calculation to properly convert units.Dimensional homogeneityAll equations must be dimensionally homogeneous.131415SYSTEMS AND CONTROL VOLUMES•System: A quantity of matter or a region in space chosen for study. •Surroundings: The mass or region outside the system•Boundary: The real or imaginary surface that separates the system from its surroundings.•The boundary of a system can be fixed or movable.•Systems may be considered to be closed or open. •Closed system (Control mass): A fixed amount of mass, and no mass can cross its boundary1617•Open system (control volume): A properly selected region in space. •It usually encloses a device that involves mass flow such as a compressor, turbine, or nozzle.•Both mass and energy can cross the boundary of a control volume.•Control surface: The boundaries of a control volume. It can be real or imaginary.A control volume can involve fixed, moving, real, and imaginary boundaries.18PROPERTIES OF A SYSTEM•Property: Any characteristic of a system. •Some familiar properties are pressure P, temperature T, volume V, and mass m. •Properties are considered to be either intensive or extensive. •Intensive properties: Those that are independent of the mass of a system, such as temperature, pressure, and density. •Extensive properties: Those whose values depend on the size—or extent—of the system.•Specific properties: Extensive properties per unit mass.19Continuum•Matter is made up of atoms that are widely spaced in the gas phase. Yet it is very convenient to disregard the atomic nature of a substance and view it as a continuous, homogeneous matter with no holes, that is, a continuum. •The continuum idealization allows us to treat properties as point functions and to assume the properties vary continually in space with no jump discontinuities.•This idealization is valid as long as the size of the system we deal with is large relative to the space between the molecules. •This is the case in practically all problems.•In this text we will limit our consideration to substances that can be modeled as a continuum.20DENSITY AND SPECIFIC GRAVITYDensity is mass per unit volume; specific volume is volume per unit mass.Specific gravity: The ratio of the density of a substance to the density of some standard