# Engineering Thermodynamics/Preface

## Goals

Thermodynamics is the study of the relationships between HEAT (thermos) and WORK (dynamics). Thus, it deals with energy interactions in physical systems. Classical thermodynamics can be stated in four laws called the zeroth, first, second, and third laws respectively. The laws of thermodynamics are empirical, i.e., they are deduced from experience, and supported by a large body of experimental evidence.

The topic of thermodynamics is taught in Physics and Chemistry courses as part of the regular curriculum. This book deals with Engineering Thermodynamics, where concepts of thermodynamics are used to solve engineering problems. Engineers use thermodynamics to calculate the fuel efficiency of engines, and to find ways to make more efficient systems, be they rockets, refineries, or nuclear reactors.

Thermodynamics is the science that deals with transfer of heat and work.

Engineering thermodynamics develops the theory and techniques required to use empirical thermodynamic data effectively. However, with the advent of computers most of these techniques are transparent to the engineer, and instead of looking data up in tables, computer applications can be queried to retrieve the required values and use them in calculations. There are even applications which are tailored to specific areas which will give answers for common design situations. But thorough understanding will only come with knowledge of underlying principles, and the ability to judge the limitations of empirical data is perhaps the most important gain from such knowledge.

One aspect of "engineering" in the title is that a lot of the data used is empirical (e.g. steam tables), since you won't find clean algebraic equations of state for many common working substances.

This book is a work in progress. This course forms the foundation for the Heat Transfer course, where the rate and mechanisms of transmission of energy in the form of heat is studied.

## Chapters

• The first chapter is an introduction to thermodynamics, and presents the motivation and scope of the topic.
• The second chapter, Thermodynamic Systems, defines some basic terms which are used throughout the book. In particular, the concepts of system and processes are discussed.
• The zeroth law is stated and the concept of temperature is developed.
• The next chapter, First Law, develops ideas required for the statement of the first law of thermodynamics.
• Second Law deals with heat engines and the concept of entropy.
• Applications of the tools developed in the previous chapters are illustrated, including the use of thermodynamics in everyday engineering situations.
• The Appendix gives a list of tables for some commonly used properties.