Preface – Thermal Engineering


It gives us immense pleasure to present the book on Thermal Engineering. This book is intended for undergraduate students of mechanical, chemical or process, power, aerospace and automobile engineering. The content covers the syllabi of all the subjects pertaining to thermal engineering such as applied thermodynamics, power plant engineering, energy conversion and management, internal combustion engines, turbomachinery, gas turbines and jet propulsion, and refrigeration and air-conditioning taught at different levels of engineering curriculum.

From the vast experience of teaching, we feel that the students are lacking in fundamental concepts of different aspects of thermal engineering. The basic objective of an introductory course of thermal engineering should be to build fundamental understanding together with analytical and problem solving abilities. It is, therefore, imperative to accentuate the basic issues to develop a solid foundation during the different time-frame starting from the first year to the final year of undergraduate studies. The present text is an endeavour towards the goal by offering the students a text book on thermal engineering in a most comprehensive manner.

Salient features of the present text are given below:

  • Detailed description of intricate physics behind every physical phenomenon
  • Stresses on physical understanding to develop mathematical modelling skills for solving real-life problems related to thermal engineering
  • After completion of illustrations, summaries are highlighted for quick revision of the topics and findings and conclusion are made therein
  • A large number of Solved Examples, Multiple-choice Questions, Review Questions and Exercises in each chapter for easy assimilation of the subject matter
  • Solved examples based on questions from reputed institutes/universities as well as from Previous Question Papers of GATE/IES/IAS
  • Multi-choice Questions from GATE/IES/IAS with explanatory notes to help the students to prepare for different competitive examinations

This book provides a single core level text on ‘Thermal Engineering’. An effort has been made for a well-balanced coverage of physical concepts, mathematical operations and practical demonstrations within the scope of the course. Throughout the text, SI units have been used. This book is divided into twenty chapters.

Chapter 1 starts with the description of fuels and the detailed analysis of combustion. The analysis of flue gas and procedure for determination of calorific value of fuel using different types of calorimeter are discussed. Chapter 2 deals with properties of steam. The property changes during transformation of steam into different phase and for different processes are shown through different plots like p–v, T–s and h–s. Dryness fraction of steam and its measurement using different calorimeter are discussed. Chapter 3 discusses different types of steam generators used for power generation. Chapter 4 deals with steam power cycle where basic and improved cycles are discussed. Chapter 5 is devoted to describe the working of steam engine together with the mathematical analysis. An elaborate in-depth discussion on flow through steam nozzle is presented in Chapter 6.

The next two chapters (Chapters 7 and 8) deal with the principle of operation of different types of steam turbines and steam condensers. Chapter 9 discusses the gas power cycles utilised in various cycles. The working principle and the function of different components of internal combustion engines are discussed at length in Chapter 10. Two stroke and four stroke engines as well as spark ignition and compression ignition engines are considered. Chapter 11 deals with the analysis of performance characteristics of internal combustion engines at different working conditions.

The next four chapters (Chapters 12, 13, 14 and 15) deal with the working principle of four different types of compressors, namely, reciprocating, rotary, centrifugal and axial flow compressors. Chapter 16 is concerned with the details of different components of gas turbine and their functions. Chapter 17 is devoted to present different jet propulsion systems together with the associated cycles. Different refrigeration systems and their components are discussed at length in Chapters 18 and 19. Chapter 20 deals with psychrometrics where the properties of atmospheric air together with different processes are presented by psychrometric chart. Fundamentals of different air-conditioning systems are discussed.

Apart from undergraduate students, this book will provide fundamental information as required by the practising engineers in the field actual operation in different industries. Students pursuing diploma can also be benefited out of this text. The text would be extremely helpful for various competitive examinations such as GATE, IES, IAS, etc.

The complete solutions manual is also available for the faculty members at

Prof. Singh places on record with gratitude the moral support received from his family members, children and grandchildren. Dr Pati is indebted to his colleagues and students at NIT Silchar for many fruitful interactions. Dr Pati expresses his gratitude to his mother, father-in-law, mother-in-law, wife Munmun, son Soumik and relatives for their persistent encouragement and support and the tolerance they have meted out during long absence from family life while perusing the present endeavour. The cooperation received from the publishers and in particular from Ms. Harsha Singh and Mr. M. Balakrishnan is highly appreciated.

Despite all our efforts, it is possible that some unintentional errors are still remaining in the text. We would gracefully acknowledge if any such errors are pointed out for necessary corrections and would be extremely thankful to the readers for their constructive suggestions and healthy criticism for further improvement of the text. If you have comments, suggestions or corrections, please email us at

Sadhu Singh
Sukumar Pati