Physics
Thermodynamics
Thermodynamics is the branch of physics that deals with the relationships between heat, work, and energy. It encompasses the study of how energy is transferred as heat and work, and how these processes affect the properties of matter. Thermodynamics also includes the laws governing these energy transformations, such as the first and second laws of thermodynamics.
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12 Key excerpts on "Thermodynamics"
eBook - PDF- Gerard Olivier, Vincent Lemort, Georges de Pelsemaeker(Authors)
- 2023(Publication Date)
- Wiley(Publisher)
1 1 Fundamentals 1.1 Introduction This textbook deals with the study of different vehicle thermal systems and components from an energy engineering point of view. It is therefore necessary to recall the fundamentals of heat trans- fer as well as Thermodynamics and some elements of fluid mechanics for a good understanding of the content of the next Chapters 2, 3, and 4. This is the objective of the present chapter, the content of which has been largely summarized from major reference textbooks, especially those of Incropera and DeWitt (2002), Çengel and Boles (2006), Braun and Mitchell (2012), and Klein and Nellis (2016). 1.2 Fundamental Definitions in Thermodynamics Thermodynamics is the branch of physics that studies conversions between heat and work in one or the other direction. Thermodynamics is particularly useful for the analysis of components and systems presented in this book. Thermodynamics makes use of some important notions to which the reader should become familiar. 1.2.1 System, Surroundings, and Universe In Thermodynamics, a system is defined as a delimited region of space or a quantity of matter that is investigated. The concept of “investigation” may still be a little bit fuzzy and will progressively develop. Let’s say that investigating a system means quantifying its energy performance and the relation between this performance and operating conditions. The system is delimited by a boundary (Figure 1.1). A boundary has neither mass nor thickness. The surroundings of the system are the region of space or the quantity of matter that is outside the system. Hence, the boundary is the sur- face that separates the system from its surroundings. The system and its surroundings constitute the universe. Among the systems, one can distinguish the closed systems and the open systems. A closed system does not exchange any mass with its surroundings.
eBook - PDFAn Introduction to Equilibrium Thermodynamics
Pergamon Unified Engineering Series
- Bernard Morrill, Thomas F. Irvine, James P. Hartnett, William F. Hughes(Authors)
- 2013(Publication Date)
- Pergamon(Publisher)
1 First Law of Thermodynamics 1-1 Thermodynamics The field of science called Thermodynamics concerns itself with the study of energy and the transformation of that energy. Historically, this branch of science arose from the study of heat. The ability to convert heat into mechanical energy served as the driving force in the evolution of Thermodynamics. The last three centuries have seen the focal point of interest in Thermodynamics pass through a spectrum from heat engines to relativistic Thermodynamics. Even after three centuries, it is not possible to say that the science of Thermodynamics is complete. This text is intended to serve for a first or introductory course in Thermodynamics. The usual introduction to Thermodynamics is by way of the classical or macroscopic concepts which follow fairly close to the historical evolution of the subject. By macroscopic, we mean that the system under investigation is large enough to be visible and in the main, such properties of the system as pressure, temperature, and mass, can be measured by laboratory devices. The usual or classical approach to the study of Thermodynamics concerns itself with macroscopic observations of thermal properties. The properties observed, however, stem from the complex motions of the constituent particles of a system. To base an introduction to the science of Thermodynamics solely on macroscopic observations and concepts of matter admits only a limited point of view. This latter statement does not deny the benefits of the classical approach to the study of Thermodynamics. It does, however, allow the use of a statistical concept based upon a microscopic view of a thermodynamic system whenever it is thought that such an approach provides insights to 1 2 First Law of Thermodynamics the student. It will be seen that the expected values of certain statistical properties correspond, and are equal to, some of the macroscopic properties which can be measured directly or indirectly.
eBook - PDF- Tanjina Nur, University of Technology Sydney, Australia(Authors)
- 2019(Publication Date)
- Delve Publishing(Publisher)
INTRODUCTION TO Thermodynamics CHAPTER 1 CONTENTS 1.1. Introduction ........................................................................................ 2 1.2. Temperature, Heat, And Internal Energy .............................................. 3 1.3. System .............................................................................................. 12 1.4. Branches of Thermodynamics ........................................................... 13 1.5. Laws of Thermodynamics .................................................................. 13 1.6. Applications of Thermodynamics ...................................................... 15 1.7. Coefficient of Thermal Expansion ...................................................... 25 1.8. The Greenhouse Effect ...................................................................... 26 1.9. Equilibrium ....................................................................................... 34 Atmospheric Thermodynamics 2 1.1. INTRODUCTION Thermodynamics refers to the study of equilibrium states for a particular system which has been exposed to some energy transformation. It deals with the transformation of heat from mechanical work. Thermodynamics is defined as the study of thermal energy and the behavior. The applications of Thermodynamics include that boiling water being hot and ice being cold. The diversity between the two parameters is usually detected naturally based on the ability to sense heat and vice versa (Shahrina, 2009). In the ancient times, Greeks believed that the world was mainly made up of four major elements, that is: • earth; • water; • fire; and • air. However, they had shortcomings since they did not fully understand the nature of the heat. The Greeks in those ancient times were able to operate simple mechanics devices. Some of these simple machines included: • the pulley; • the lever; • the wheel; • the screw; and • the gear.
eBook - PDFThermo and Fluid Dynamics
Recent Advances
- Dritan Hoxha(Author)
- 2019(Publication Date)
- Arcler Press(Publisher)
A GENERAL VIEW ON Thermodynamics CHAPTER 1 CONTENTS 1.1. What Is Thermodynamics? ....................................................................................... 2 1.2. Etymology of Thermodynamics ................................................................................ 3 1.3. Why is Thermodynamics Important? ........................................................................ 8 1.4. A Short View of The Quantities Involved in Thermodynamics ................................. 10 1.5. A Short View of the Theories and Laws Contained in Thermodynamics .................. 12 References .................................................................................................................... 17 Thermo and Fluid Dynamics: Recent Advances 2 1.1. WHAT IS Thermodynamics? All of us would have heard at least once the words “thermo” or “Thermodynamics” but only a few people know what do they really stand for. From the Greek language, “thermo” means heat and “dynamics” means something in motion. Thus, by definition, “ Thermodynamics is the branch of Physics that deals with the relationships and interaction between heat and other forms of energy. In particular, it describes how thermal energy turns into other forms of energy and vice-versa and how it affects the behavior of matter” [1]. The type of energy involved in Thermodynamics is known as “thermal energy.” It is the kind of energy that a certain substance or system owns due to its temperature [1]. As you may know, temperature is a physical quantity related to the particles’ motion, thus thermal energy represents the energy of molecules motion or vibration. Here I will make a parenthesis. People often confuse heat and thermal energy or worse, they consider them as the same thing. Heat and thermal energy, earlier, used to be considered as synonyms. But they differ as follows: Heat is the thermal energy transferred across a boundary of one region of matter to another.
eBook - ePub- Callum Hill(Author)
- 2012(Publication Date)
- Routledge(Publisher)
2
Thermodynamics
(the science of energy and change)
Introduction
Thermodynamics is one of the most powerful tools at our disposal for the study of the sustainability of processes. Although a development that was associated with the invention of the steam engine, it has proved to be of much wider application in the fields of chemistry, ecology, biochemistry, cosmology and information theory. If we wish to understand anything about the sustainability of a process, it is clearly important to know about energy use, recycling and other facets concerned with the management or utilization of resources and it is Thermodynamics that provides the basis for the answers to many of the questions. Although this book concerns physical resources and their exploitation, it is necessary to use energy in the processing of these materials and so it follows that we have to understand the properties of energy and how it interacts with matter.What is energy?
Energy is used to move things, to drive machinery, to provide heat and electricity, and to stay alive. Without energy there would be no change and time would not exist. But what exactly is it? For many years energy was seen as a mysterious force that acted upon matter and somehow gave it ‘life’ and it was given a name that reflected this idea, ‘vis viva’. Even now, much misunderstanding exists; it is common to see the words ‘energy’ and ‘power’ used interchangeably although they mean different things, or references to energy ‘consumption’, whereas energy is always conserved. There is no doubt that something is being consumed when we use energy and we shall examine later in this chapter what this something is.
- Anthony R. Philpotts, Jay J. Ague(Authors)
- 2022(Publication Date)
- Cambridge University Press(Publisher)
8 Introduction to Thermodynamics Overview Thermodynamics, the study of energy, is one of the most important subjects in all of science. Historically, it evolved from the desire to understand the efficiency of machines, in particular steam engines. Much of its terminology therefore centers around heat and work, especially work associated with expanding gas. Thermodynamics, however, deals with the transfer of other forms of energy as well, such as that associated with chemical reactions. Although heat and mechanical work done by expanding gas are important in geology, for example in the cooling of magma or the explosion of a volcano, the study of chemical energies is of greatest value to petrology. Thermodynamics is particularly useful in the study of processes that take place within the Earth, where they cannot be observed directly. The ever-increasing availability of thermodynamic data for common minerals, magmas, and fluids has resulted in a rapid growth in the application of Thermodynamics to petrology. It is possible, for example, to calculate melting points of minerals, amounts and compositions of minerals crystallizing from magma, temperatures and pressures of metamorphic reactions, and compositions of ore-forming solutions. Computer programs are now routinely used for such calculations, but some knowledge of Thermodynamics is essential to understand what the programs are actually doing. Little more than a descriptive treatment of petrology could be given if Thermodynamics were omitted. However, an entire book would be required to fully develop all the thermodynamic relations encountered in petrology. In this and the following two chapters, the focus is on the more important fundamental concepts. Physical chemistry and petrologic thermodynamic texts will provide the reader with more extensive coverage (e.g., Zemansky 1943; Wood & Fraser 1977; Powell 1978; Castellan 1983; Atkins & de Paula 2014).
eBook - PDF- Marc J. Assael, William A. Wakeham, Anthony R. H. Goodwin, Stefan Will, Michael Stamatoudis(Authors)
- 2011(Publication Date)
- CRC Press(Publisher)
1 1 Chapter Definitions and the 1 st Law of Thermodynamics 1.1 INTRODUCTION The subjects of Thermodynamics, statistical mechanics, kinetic theory, and transport phenomena are almost universal within university courses in physical and biological sciences, and engineering. The intensity with which these topics are studied as well as the balance between them varies considerably by disci-pline. However, to some extent the development and, indeed, ultimate practice of these disciplines requires Thermodynamics as a foundation. It is, therefore, rather more than unfortunate that for many studying courses in one or more of these topics Thermodynamics present a very great challenge. It is often argued by students that the topics are particularly diffi cult and abstract with a large amount of complicated mathematics and rather few practical examples that arise in everyday life. Probably for this reason surveys of students reveal that most strive simply to learn enough to pass the requisite examination but do not attempt serious understanding. However, our lives use and require energy, its conversion in a variety of forms, and understanding these processes is intimately connected to Thermodynamics and transport phenomena; the latter is not the main subject of this work. For example, whether a particular proposed new source of energy or a new product is genuinely renewable and/or carbon neutral depends greatly on a global energy balance, on the processes of its production, and its interaction with the environment. This analysis is necessarily based on the laws of Thermodynamics, which makes it even more important now for all scientists and engineers to have a full appreciation of these subjects as they seek to grapple with increasingly complex and interconnected problems. This book sets out to provide answers to some of the questions that under-graduate students and new researchers raise about Thermodynamics and sta-tistical mechanics.
eBook - PDF- Robert DeHoff(Author)
- 2006(Publication Date)
- CRC Press(Publisher)
Kinetic energy, which is associated with the motion, translation or rotation, of a particle or body and nothing else. 2. Potential energy, which is associated with the position of a particle or body in a potential field and nothing else. 3. Internal energy, which is associated with the internal condition of the body and does not otherwise depend upon its motion or position in space. Thermodynamics at first focuses upon the influences that change the internal condition of a system at rest. The apparatus ultimately is extended to include potential and kinetic energy as well as internal energy (Chapter 14). In its most pretentious form the first law may be stated for the behavior of the universe. In practical applications the focus of attention is on some small subset of the universe, called “the system.” Except for the case of a system which is isolated Thermodynamics in Materials Science 32 from its surroundings, changes that occur inside the system are always accompanied by changes in the condition of the matter in the vicinity of the system. The part of the universe that is external to the system but is also affected by changes that are caused to occur in the system is called “the surroundings” (Figure 3.1). Thus, from the standpoint of any particular process that may occur in practice, the sum of the changes that occur in the system and the surroundings includes all of the changes in the universe associated with that process (Figure 3.1). By the first law the total energy of the universe cannot change for any process. Energy can be transported, or converted from one form to another but cannot be created or destroyed. Since conversion of energy from one form to another does not change the total quantity of energy, the only way that the internal energy of a system can change is by transferring energy across its boundary.
eBook - PDFQuantum Thermodynamic Processes
Energy and Information Flow at the Nanoscale
- Guenter Mahler(Author)
- 2014(Publication Date)
- Jenny Stanford Publishing(Publisher)
Furthermore, 176 Thermodynamics introducing changes means to couple the system to an appropriate physical environment. These couplings must be weak in order to guarantee additivity of the various subsystem energies involved. Work is a concept originally defined within classical mechanics. It characterizes the change of the total energy of some mechanical system due to a process, during which an external force is applied. A simple example would be the action of the gravitational force on a falling body. Such entirely mechanical models may serve as work reservoirs, see Definition 4.8. Models which can only accept heat are called heat reservoirs. General (thermal) systems have access to both types of energy change. Observation is a central theme not only in quantum mechanics but also in Thermodynamics. Not being an observable does not mean that work or heat could not be measured at all. However, the respective strategy has to be indirect: In quantum mechanics the measurement of work can be reduced to two separate energy measurements, one at the beginning and one at the end of the respective process. Of course, for this strategy to hold one has to make sure that no heat has been exchanged in parallel. Such quantum processes under observation have been studied in the context of the so-called quantum Jarzynski relation. The results are measurement-induced fluctuations [Mukamel (2003)]. These fluctuations are quantum mechanical in origin, but, nevertheless, fulfill the same relations as derived within a classical context (cf. Section 4.2.7). 4.2.6 What is the Role of Information in Thermodynamics? Can one switch between different levels of description? A key concept appears to be information. However, for information to have a say, it should be connected to physics, it must become operational. “It’s about this man who is a very good man, who dies and goes up to heaven and he meets an angel there, and the angel has a big bowl filled with hard spheres.
- S. Bobby Rauf(Author)
- 2021(Publication Date)
- River Publishers(Publisher)
Chapter 1 Introduction to Energy, Heat and Thermodyna mics INTRODUCTION The term “Thermodynamics” comes from two root words: “ther-mo,” which means heat, and “ dynamic, ” meaning energy in motion, or power. This also explains why the Laws of Thermodynamics are some-times viewed as Laws of “Heat Power.” Since heat is simply thermal energy, in this chapter, we will review energy basics and lay the foundation for in depth discussion on heat en-ergy and set the tone for discussion on more complex topics in thermody-namics. ENERGY The capacity of an, object, entity or a system to perform work is called energy. Energy is a scalar physical quantity. In the International System of Units (SI), energy is measured in Newton-meters (N-m) or Joules, while in the US system of units, energy is measured in ft-lbf, Btu’s, therms or calories. In the feld of electricity, energy is measured in watt-hours, (Wh), kilowatt-hours (kWh), Gigawatt-hours (GWh), Terawatt-hours (TWh), etc. Units for energy, such as ft-lbs and N-m, point to the equivalence of energy with torque (moment) and work . This point will be discussed later in this chapter. Energy exists in many forms. Some of the more common forms of energy, and associated units, are as follows: 1) Kinetic Energy 1 ; measured in ft-lbf, Btus, Joules, N-m (1 N-m = 1 Joule), etc. Where, Btu stands for British thermal units 1 2 Thermodynamics Made Simple for Energy Engineers 2) Potential Energy 1 ; measured in ft-lbf, Btus, Joules, N-m, etc. 3) Thermal Energy 1 , or heat (Q); commonly measured in calories, Btus, Joules, therms, etc. 4) Internal Energy 1 , (U); commonly measured in Btu’s, calories or Joules. 5) Electrical Energy ; measured in Watt-hours (Wh), killowatt-hours (kWh) and horsepower-hours (hp-hrs), etc. 6) Gravitational Energy ; measured in ft-lbf, Joules, N-m, etc. 7) Sound Energy ; measured in Joules. 8) Light Energy ; measured in Joules. 9) Elastic Energy ; measured in ft-lbf, Btus, Joules, N-m, etc.
No longer available |Learn more- Irving Granet, Maurice Bluestein(Authors)
- 2014(Publication Date)
- CRC Press(Publisher)
59 2 Work, Energy, and Heat LEARNING GOALS After reading and studying the material in this chapter, you should be able to 1. State the definitions of work, energy, and heat 2. Use the fact that both work and heat are forms of energy in transition 3. Apply the convention that heat into a system is to be taken as a positive quantity and that work out of a system is also to be taken as a positive quantity (This con-vention is taken from the customary power-producing cycle in which heat into a system is used to generate useful work.) 4. Show that internal energy is a form of energy in which a body is said to possess internal energy by virtue of the motion of the molecules of the body 5. Differentiate between a nonflow or closed system and a flow or open system 6. Understand the origin of the term flow work and apply it to a flow system 7. Use the fact that the work of a quasi-static, nonflow system is the area under the pressure–volume curve 8. Understand the difference between sensible heat and latent heat 2.1 Introduction In Chapter 1, certain concepts were arrived at by considering the motion of gas particles in an enclosure. Briefly, pressure was found to involve the principle of momentum inter-change with the container walls, temperature was associated with the motion of the par-ticles, and density was taken to be a measure of the number of particles per unit volume. This simple analysis followed the history of a single particle, and it was subsequently generalized to all the particles in the enclosure. This type of analysis is representative of a microscopic description of the processes occurring within the boundaries of the defined system, because the history of a single particle was followed in detail. Rather than pursue further the microscopic concept of matter, we shall be concerned with the macroscopic, or average, behavior of the particles composing a system.
- Raymond Serway, John Jewett(Authors)
- 2018(Publication Date)
- Cengage Learning EMEA(Publisher)
The first law of Thermodynamics is a spe- cial case of the law of conservation of energy that describes processes in which only the internal energy 5 changes and the only energy transfers are by heat and work: DE int 5 Q 1 W (19.11) Look back at Equation 8.2 to see that the first law of Thermodynamics is contained within that more general equation. First law of Thermodynamics f P f P i V V i V f P i f P f P i V V i V f P i f P f P i V V i V f P i A constant-pressure compression followed by a constant-volume process A constant-volume process followed by a constant- pressure compression An arbitrary compression a b c Figure 19.6 The work done on a gas as it is taken from an initial state to a final state depends on the path between these states. 5 It is an unfortunate accident of history that the traditional symbol for internal energy is U, which is also the tra- ditional symbol for potential energy as introduced in Chapter 7. To avoid confusion between potential energy and internal energy, we use the symbol E int for internal energy in this book. If you take an advanced course in thermody- namics, however, be prepared to see U used as the symbol for internal energy in the first law. Copyright 2019 Cengage Learning. All Rights Reserved. May not be copied, scanned, or duplicated, in whole or in part. Due to electronic rights, some third party content may be suppressed from the eBook and/or eChapter(s). Editorial review has deemed that any suppressed content does not materially affect the overall learning experience. Cengage Learning reserves the right to remove additional content at any time if subsequent rights restrictions require it. 19.5 The First Law of Thermodynamics 515 Let’s discuss each of the three terms in the first law for various processes through which a gas is taken. As a model, let’s consider the sample of gas contained in the piston–cylinder apparatus in Figure 19.7.
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