Russ College of Engineering and Technology

Mechanical Engineering Department

Engineering Thermodynamics - A Graphical Approach
by Israel Urieli (
latest update: 8/3/2018)

This web resource is intended to be a totally self-contained learning resource in Engineering Thermodynamics, independent of any textbook. It is designed to be suitable for a two course sequence for Mechanical Engineering majors. It may, however, be used in any format and for any purpose, including self-study. The various unique pedagogical features of this web resource are discussed in Paper AC 2010-47, presented at the 2010 ASEE Annual Conference (refer also to the OU Video). It is licensed under a Creative Commons Attribution-Noncommercial-Share Alike 3.0 United States license and as such is freely available. Comments and constructive criticism are welcomed by the author.

In Part 1 we introduce the First and Second Laws of Thermodynamics. Rather than applying these laws in terms of components and processes we have chosen a more interesting approach of applying them to complete cycles or systems. The ideal Stirling cycle machine is developed as a prime example of both Laws (refer to a paper: A Meeting between Robert Stirling and Sadi Carnot in 1824 presented at the 2014 ISEC.), and complete ideal heat engines, steam power plants and refrigeration systems are evaluated in Chapters 3 and 4. Where appropriate, we introduce graphical two-dimensional plots to evaluate the performance of these systems rather than relying on equations and tables. This enables intuitive visualization of the solutions to a high degree of accuracy.

Part 1 - Introduction to the First and Second Laws of Thermodynamics

Chapter 1: Introductory Concepts, Units, and Definitions

Chapter 2: Properties of Pure Substances

a) Phase Change, Property Tables and Diagrams
b) The Ideal Gas Equation of State

Thermodynamic Properties Tables and Charts

Chapter 3: The First Law of Thermodynamics for Closed Systems

a) The Energy Equation for Closed Systems
b) Ideal Stirling Cycle Machines (Engines / Coolers)
c) The Air Standard Diesel Cycle (Compression-Ignition) Engine
d) The Air Standard Otto Cycle (Spark-Ignition) Engine

Chapter 4: The First Law of Thermodynamics for Control Volumes

a) The Energy Equation for Control Volumes
b) Steam Power Plants
c) Refrigeration Systems

Chapter 5: The Second Law of Thermodynamics

Chapter 6: Entropy - A New Property

a) Defining and Evaluating Entropy

We present an Entropy Summary Sheet, Isentropic Processes Summary Sheet, and an Adiabatic Efficiency Summary Sheet of all the relevant equations relating to this Section.

b) Aircraft Gas Turbine Engines

In Part 2 we introduce the concept of Exergy to determine theoretical limits of performance of various thermodynamic components and systems, followed by advanced application of steam power plants. The chapter on Carbon Dioxide as a refrigerant does not appear in any textbook that I am aware of. Because of the Global Warming crisis, the currently used refrigerant, R134a, will be banned from usage in automobile air conditioning systems in Europe within a few years. Among the alternatives being developed we prefer to return to Carbon Dioxide as the refrigerant of choice. Finally we introduce mixtures of water vapor and air and their application in air-conditioning and cooling tower systems, and conclude with an introduction to combustion processes.

Part 2 - Applied Engineering Thermodynamics

Chapter 7: Exergy - Maximum Available Work Potential

a) Reversible Work, Irreversibility, Second Law Efficiency
b) Examples of Adiabatic Control Volumes
c) Heat Transfer from a Thermal Source

Chapter 8: Steam Power Cycles

a) Ideal Rankine and Reheat Cycles
b) Regenerative Cycles - Open and Closed Feedwater Heaters
Case Study - The General James M. Gavin Steam Power Plant

Chapter 9: Carbon Dioxide (R744) The New Refrigerant

Chapter 10: Air - Water Vapor Mixtures

a) Humidity and the Adiabatic Saturation Process
b) The Psychrometric Chart and Air Conditioning Processes
c) Cooling Towers for Steam Power Plants

Chapter 11: Combustion

Combustion Molar Enthalpy Tables

The General James M Gavin Steam Power Plant near Cheshire, Ohio
full capacity: 2,600,000kW

Photograph courtesy of Randy Sheidler, Gavin Power Plant


Except for the Ohio University header and footer, including their graphics, Engineering Thermodynamics by Israel Urieli is licensed under a Creative Commons Attribution-Noncommercial-Share Alike 3.0 United States License

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