WITH THE DISCLAIMER that we will consider neither situations involving nuclear transformations nor situations where relativistic effects are important, this chapter presents general and specific statements of mass conservation. We consider, first, closed thermodynamic systems. Before extending the mass conservation principle to open systems (control volumes), the concept of a flow rate and its relationship to the average velocity of a flowing fluid is introduced. The concept of steady-state, steady flow for open systems is presented. The principle of mass conservation is then applied to both steady and unsteady flows for single and multiple streams into and out of the system.

IN THIS CHAPTER, we introduce and define the subject of thermodynamics. We also introduce three complex practical applications of our study of thermodynamics: the fossil-fueled steam power plant, jet engines, and the spark-ignition reciprocating engine. To set the stage for more detailed developments later in the book, several of the most important concepts and definitions are presented here. These include the concepts of: open and closed thermodynamic systems; thermodynamic properties, states, and cycles; and equilibrium and quasi-equilibrium processes. The chapter concludes with an organizational overview of engineering thermodynamics and presents some ideas of how you might optimize the use of this textbook based on your particular educational objectives.

THE CHAPTER EXAMINES the principles of chemical equilibrium and phase equilibrium as extensions of the second law. We revisit entropy and define two other second-law properties: the Gibbs function and the Helmholtz free energy. The chapter explores how equilibrium relates to these three properties. The chapter focuses on the conditions of fixed temperature and pressure to explore chemical equilibrium. The equilibrium constant is defined and used to determine the detailed composition of a system. Simple, single, equilibrium reactions (dissociations) are investigated. The equilibrium constant approach is extended to multiple equilibria. The chapter also develops how minimization of the Gibbs function establishes the conditions for liquid–vapor (nonreacting) equilibrium.

THE FIRST LAW OF THERMODYNAMICS can be mathematically expressed in a variety of ways. All these expressions, however, are easily viewed as rearrangements of the statement that energy can neither be created nor destroyed but only converted from one form to another. In contrast, there is no single universally agreed statement of the second law of thermodynamics. Kline [1] indicates that many seemingly different statements have been accepted as the second law, all of which, however, can be shown to be equivalent after careful and sometimes subtle application of logic. This multiplicity of apparently disparate statements can lead to confusion in understanding the second law.

IN THIS CHAPTER, we see how steady-flow devices combine to form complex systems for power production, propulsion, heating, and cooling. Not only are such systems important from an engineering perspective, but more generally, they are essential to everyday life in industrialized societies. Here we analyze these systems to understand their basic operation and to determine various performance measures. Thermodynamic cycle efficiency, first introduced in Chapter 6, provides a dominant theme for this chapter. Here we investigate in some detail the energy conversion efficiency of the various systems just listed. In some sense, this chapter is the culmination of all the preceding chapters. Chapter 9 not only provides an opportunity to integrate knowledge gained from previous chapters but also provides interesting applications that can be explored in parallel with earlier chapters.illustrates the key role that Chapter 9 plays in our study. The system analysis is shown as bridging, or using, all the previous topics.

IN THIS CHAPTER, we review the concept of energy and the various ways in which closed and open systems can possess energy at both microscopic (molecular) and macroscopic levels. We also carefully define heat and work, which are boundary interactions and, therefore, not properties of a system or control volume. The chapter concludes with a brief examination of the rate laws that govern heat transfer.illustrates how this chapter relates to other thermodynamics topics. We begin with a brief historical overview of our subject matter.

THE FIRST LAW of thermodynamics can be mathematically expressed in a variety of ways. All these expressions, however, are easily viewed as rearrangements of the statement that energy can neither be created nor destroyed but only converted from one form to another. In contrast, there is no single universally agreed upon statement of the second law of thermodynamics. Kline [1] indicates that many seemingly different statements have been accepted as the second law, all of which, however, can be shown to be equivalent after a careful and sometimes subtle application of logic. This multiplicity of apparently disparate statements can lead to confusion in understanding the second law. In this chapter, we examine several statements of the second law and discuss the consequences of each.

IN THIS CHAPTER, we apply the basic conservation principles and other key concepts to analyze a number of important devices. Here we investigate typical components of more complex systems; these components include nozzles, diffusers, throttles, pumps, compressors, fans, turbines, and heat exchangers. In Chapter 9, we will combine these simple devices in more complex systems, which include steam power plants, jet engines, other power and propulsion cycles, heat pumps, refrigeration cycles, and air conditioning and humidification systems.

IN THIS CHAPTER, we apply the fundamental principle of energy conservation to both closed and open thermodynamic systems. In our analyses of closed (fixed-mass) systems, we will express energy conservation for incremental and finite changes in state and at an instant. In dealing with open systems, we again follow a hierarchical development by starting with simple, steady-state, steady-flow cases and then adding detail and complexity to arrive at more general statements of energy conservation. We apply the energy conservation principle to analyses of steady-flow devices, linking our theoretical developments to practical applications.illustrates the key role that this chapter plays in our study.

Crystallization is an extremely important process with extensive industrial applications including, but not limited to, the manufacture of electronics, explosives, fine chemicals, and pharmaceuticals. As such, controlling both crystal shape and crystal structure is vital for the production of high-quality products with desirable properties. However, the processes that govern crystallization, crystal growth, and crystal nucleation are not well understood at present. This is due in part to the limitations of experimental techniques in studying such processes because of the small number of molecules, often tens or hundreds, involved. Furthermore, experimental strategies for identifying and analyzing crystal structures (which may have serious implications in terms of intellectual property rights) and controlling crystal shape are not always successful in yielding the optimal product and often can be costly and time consuming.