Heat and Mass Transfer: Fundamentals and Applications

Citation

Çengel, Y. A., & Ghajar, A. J. (2020). Heat and Mass Transfer: Fundamentals and Applications (6th ed.). McGraw-Hill Education.

Chapter Summary

The sixth edition lists 17 chapters: fourteen in the printed book, plus three online chapters (cooling of electronic equipment, heating and cooling of buildings, and refrigeration and freezing of foods), and an appendix of property tables and charts. The publisher describes the book as combining complete coverage of the basic principles of heat transfer with a broad range of applications in a flexible format. It aims at a practical understanding by emphasizing the physics and the underlying physical phenomena, covering the standard topics with real-world, everyday applications while de-emphasizing mathematical aspects, in order to take advantage of students' intuition. The catalogue gives chapter titles without section lists, so the entries below describe what each title names.

Chapter 1: Introduction and Basic Concepts

The opening chapter, which sets out the basic concepts on which the later chapters build.

Chapters 2–5: Heat Conduction Equation; Steady Heat Conduction; Transient Heat Conduction; Numerical Methods in Heat Conduction

Four chapters on conduction. The heat conduction equation comes first, followed by steady conduction, transient conduction and, last, numerical methods in a chapter of their own.

Chapters 6–9: Fundamentals of Convection; External Forced Convection; Internal Forced Convection; Natural Convection

Four chapters on convection: first the fundamentals, then forced convection over external surfaces, forced convection in internal flows and finally natural convection.

Chapters 10–11: Boiling and Condensation; Heat Exchangers

Phase-change heat transfer and the analysis of heat exchangers, applications of the earlier conduction and convection material.

Chapters 12–13: Fundamentals of Thermal Radiation; Radiation Heat Transfer

Two chapters on radiation, with the fundamentals followed by radiation heat transfer.

Chapter 14: Mass Transfer

The last printed chapter takes up mass transfer, the subject named alongside heat transfer in the book's title.

Chapters 15–17: Cooling of Electronic Equipment; Heating and Cooling of Buildings; Refrigeration and Freezing of Foods (online chapters)

Three application chapters provided online in the sixth edition rather than in print: electronic equipment cooling, buildings, and the refrigeration and freezing of foods.

Key Concepts

The explanations below are general definitions of the topics that the chapter titles name.

Chapters 1–5: Conduction

• Heat conduction equation: the governing equation for temperature in a solid, from which steady and transient solutions follow.
• Transient conduction: how temperature changes with time in a body after its surroundings change.
• Numerical methods in heat conduction: numerical solution, such as by finite differences, of conduction problems that resist closed forms.

Chapters 6–11: Convection, Phase Change and Heat Exchangers

• Forced and natural convection: heat transfer to a moving fluid driven by an imposed flow or by buoyancy.
• Boiling and condensation: heat transfer with a change of phase.
• Heat exchangers: devices that transfer heat between fluids, analysed in Chapter 11.

Chapters 12–14: Radiation and Mass Transfer

• Thermal radiation: heat exchange by electromagnetic waves, treated first in its fundamentals and then between surfaces.
• Mass transfer: the movement of a species through a mixture, parallel to heat transfer in structure.

Critical Analysis

Strengths

• Physical intuition first. The publisher states that the book stresses physics and real-world applications and de-emphasizes mathematical aspects, an approach designed to draw on students' intuition.
• A complete sequence. The printed contents run from conduction through convection, phase change, heat exchangers and radiation to mass transfer, so a one- or two-semester heat transfer course can follow a single book.
• Mass transfer is included. The title promises heat and mass transfer, and the contents deliver a chapter on mass transfer after radiation.
• Applications chapters online. The three online chapters on electronics cooling, buildings and food refrigeration extend the book beyond the printed fourteen chapters.
• Substantial reference material. The sixth edition is a thick volume (1,056 pages in the international edition listing) with an appendix of property tables and charts.

Limitations

• Lighter on mathematics by design. The publisher says mathematical aspects are de-emphasized, so students who want the analytical solutions developed fully will need a more mathematical text for that purpose; the course list includes several.
• Size. At more than 1,000 pages, much of the book is for selection rather than sequential reading.
• Edition variants. The sixth edition appears under different ISBNs and in SI-unit and international forms. The listing for the SI edition shows a July 2020 publication date and the international edition is catalogued as 2019, so check the edition when comparing page numbers.

Where It Fits in the Course

Çengel and Ghajar is a main text for a first course in heat transfer. Kreith and Manglik's Principles of Heat Transfer is the closest alternative: it has eleven chapters, treats conduction, convection, radiation, phase change and heat exchangers, and has no chapter on mass transfer, whereas Çengel and Ghajar gives mass transfer a chapter. Lienhard's A Heat Transfer Textbook is an introductory book that also covers mass transfer, and its sixth edition is free to download. Nellis and Klein's Introduction to Engineering Heat Transfer pairs first-principles derivations with computational tools such as EES and MATLAB.

Bergman, Lavine, Incropera and DeWitt's Fundamentals of Heat and Mass Transfer is a more rigorous engineering text with analysis and design problems, and Ghiaasiaan's Convective Heat and Mass Transfer is a graduate-level book on convection that comes after a course based on any of these.

How to Use This Book

The book suits mechanical, chemical, aerospace and energy engineering students taking a one- or two-semester heat transfer course. The publisher lists no prerequisites; a student will want calculus, introductory thermodynamics and some fluid mechanics before the convection chapters.

• Core: Chapters 1–9 (basic concepts, conduction, convection) and Chapter 11 (heat exchangers). Read conduction before convection, following the order of the book.
• Radiation: Chapters 12–13, usually taught after convection and heat exchangers.
• Optional: Chapter 10 on boiling and condensation, Chapter 14 on mass transfer and the online application chapters, depending on the syllabus.

Use the worked examples as templates, keep the appendix property tables at hand, and read the chapters on numerical methods if the course includes computation.