A Heat Transfer Textbook

Citation

Lienhard, J. H., V, & Lienhard, J. H., IV. (2024). A Heat Transfer Textbook (6th ed., Version 6.00). Phlogiston Press. Free official edition: https://ahtt.mit.edu/

Chapter Summary

Chapter 1: Introduction

Part I, "The General Problem of Heat Exchange", opens with a chapter that defines heat transfer, relates it to the first and second laws of thermodynamics (including entropy production by heat flow), and introduces the three modes: conduction through Fourier's law, convection through Newton's law of cooling and the heat transfer coefficient, and radiation through the Stefan-Boltzmann, Wien and Planck laws. It closes with a look ahead to the three recurring tasks of the book—solving the conduction equation, finding h, and finding radiation view factors—and an explanation of the purposes of the end-of-chapter problems.

Chapter 2: Heat conduction concepts, thermal resistance, and the overall heat transfer coefficient

This chapter derives the heat conduction equation, sets out a step-by-step method for solving steady one-dimensional problems in slabs, cylinders and spheres, and develops the electrical analogy between Fourier's, Fick's and Ohm's laws. Thermal resistance networks, contact resistance, the critical radius of insulation and the overall heat transfer coefficient U (including fouling resistance) are introduced with many worked examples, and a short summary lists what the chapter has established.

Chapter 3: Heat exchanger design

Using the first law and U, the chapter derives how heat is exchanged between two fluid streams. It describes the main exchanger configurations (parallel and counterflow, shell-and-tube, cross flow), develops the logarithmic mean temperature difference and its correction factors, introduces the effectiveness–NTU method for cases where outlet temperatures are unknown, and discusses the difference between rating and sizing an exchanger. The preface describes Chapters 1–3 together as a "minicourse" in heat transfer.

Chapter 4: Conduction analysis, dimensional analysis, and fin design

Part II, "Analysis of Heat Conduction", begins by explaining what makes a conduction problem well posed and how to find general solutions, including a two-dimensional steady problem solved by separation of variables. The authors then present their own simplified approach to dimensional analysis (the "method of functional replacement" and the pi-theorem), which is used in every later chapter, and apply it to a complex steady conduction problem. The chapter ends with fin design, from the fin equation and fin efficiency to examples of fins in nature such as the plates of the Stegosaurus.

Chapter 5: Transient and multidimensional heat conduction

Opening with James Watt's improvement of the Newcomen engine as an example of wasteful transient heating, the chapter treats lumped-capacity cooling and the Biot number, series solutions for a slab, temperature-response charts and one-term approximations, and conduction into a semi-infinite region (illustrated by the forging of Japanese swords). Its final sections introduce steady multidimensional conduction—including shape factors and flux plotting—and transient multidimensional conduction by superposition of one-dimensional solutions.

Chapter 6: Laminar and turbulent boundary layers

Part III, "Convective Heat Transfer", is the largest part of the book. This chapter derives the continuity, momentum and energy equations for the laminar boundary layer on a flat plate, explains the role of the Prandtl number in linking velocity and thermal boundary layers, and obtains the heat transfer coefficient by integral methods and similarity results. It presents the Reynolds-Colburn analogy, then—in material reworked for this edition—turbulent boundary layers, heat transfer in turbulent boundary layers, and the treatment of transition for overall heat transfer.

Chapter 7: Forced convection in a variety of configurations

The chapter moves to internal flows: development of laminar flow and temperature profiles in pipes, fully developed Nusselt numbers, turbulent pipe flow and its correlations, and the idea of treating a heated pipe as a heat exchanger. It then covers noncircular ducts through the hydraulic diameter, cross flow over cylinders and tube bundles, and closes with advice on finding and judging empirical correlations for configurations beyond the reach of analysis.

Chapter 8: Natural convection in single-phase fluids and during film condensation

Because buoyancy-driven natural convection and gravity-driven film condensation share their physics, the chapter develops their governing equations side by side. It then treats laminar natural convection on a vertical isothermal plate (with dimensional analysis, data and the Churchill-Chu correlations), natural convection from cylinders, spheres, horizontal plates and enclosures, and finally laminar film condensation on plates and cylinders, including Nusselt's analysis.

Chapter 9: Heat transfer in boiling and other phase-change configurations

Starting from Nukiyama's 1934 experiment and the pool-boiling curve, the chapter explains nucleation and nucleate boiling, the hydrodynamic theory of the peak (burnout) heat flux based on Taylor instability, film boiling and its analogy with film condensation, the minimum heat flux and transition boiling. It goes on to surface and system effects, forced-convection boiling and condensation in tubes, dropwise condensation and the heat pipe.

Chapter 10: Radiative heat transfer

Part IV is this stand-alone chapter, accessible after Chapter 2. It builds on the radiation concepts of Chapter 1 to treat Kirchhoff's law and the relation between emittance and absorptance, view factors between finite black bodies and the algebra for evaluating them, the electrical-network method for heat exchange among diffuse gray bodies, radiation through absorbing and emitting gases, and solar energy, including the role of atmospheric absorption.

Chapter 11: An introduction to mass transfer

Part V, substantially revised in this edition, introduces mixture compositions and species fluxes, Fick's law for binary mixtures, the species conservation equation, and diffusion through stationary media. It develops the analogy between heat and mass transfer for convective mass transfer at low rates and applies it to simultaneous heat and mass transfer (evaporation, wet-bulb temperature). The Couette-flow (stagnant film) model then handles high mass transfer rates and their effect on heat transfer, followed by estimating transport properties of mixtures and a new section on multicomponent and nonideal diffusion.

Key Concepts

Chapter 1: Introduction

• Fourier's law: heat flux is proportional to the negative temperature gradient, with the thermal conductivity as the constant.
• Heat transfer coefficient h: the ratio of convective heat flux to the temperature difference between a surface and the fluid.
• Black-body radiation: emission governed by Planck's law, whose integral gives the Stefan-Boltzmann law.

Chapter 2: Heat conduction concepts, thermal resistance, and the overall heat transfer coefficient

• Heat conduction equation: the energy balance that, with Fourier's law, governs temperature in a solid.
• Thermal resistance: the analogue of electrical resistance, allowing composite walls and convective surfaces to be treated as circuits.
• Overall heat transfer coefficient U: a single coefficient combining all resistances between two fluids.

Chapter 3: Heat exchanger design

• Logarithmic mean temperature difference: the appropriate average temperature difference for an exchanger with constant U.
• Effectiveness–NTU method: a way to predict exchanger performance when outlet temperatures are unknown.
• Rating versus sizing: predicting the performance of a given exchanger versus choosing its size for a required duty.

Chapter 4: Conduction analysis, dimensional analysis, and fin design

• Well-posed problem: a conduction problem with the equation, boundary and initial conditions needed for a unique solution.
• Pi-theorem and functional replacement: the authors' streamlined way of reducing a problem to dimensionless groups.
• Fin efficiency: the ratio of a fin's actual heat transfer to what it would transfer if it were entirely at base temperature.

Chapter 5: Transient and multidimensional heat conduction

• Biot number and lumped capacity: when internal resistance is small relative to surface resistance, a body cools with a single uniform temperature.
• Fourier number and one-term solutions: dimensionless time, beyond which a single series term describes transient conduction.
• Semi-infinite body: the solution for heat penetrating a deep region, which later frames boundary-layer thinking.

Chapter 6: Laminar and turbulent boundary layers

• Boundary layer: the thin region near a surface where velocity and temperature change from wall to free-stream values.
• Prandtl number: the ratio of momentum to thermal diffusivity, which sets the relative thickness of the two boundary layers.
• Reynolds-Colburn analogy: a link between wall friction and heat transfer that allows one to be estimated from the other.

Chapter 7: Forced convection in a variety of configurations

• Fully developed flow: the region of a pipe where the velocity profile and dimensionless temperature profile no longer change along the flow.
• Hydraulic diameter: a length that lets circular-pipe results be adapted, with care, to noncircular ducts.
• Empirical correlations: data-based equations for Nusselt number that must still respect theoretical limits.

Chapter 8: Natural convection in single-phase fluids and during film condensation

• Rayleigh and Grashof numbers: dimensionless groups measuring buoyancy relative to viscous and thermal diffusion.
• Film condensation: condensation in which liquid forms a continuous film on the cool surface, analysed by Nusselt.

Chapter 9: Heat transfer in boiling and other phase-change configurations

• Pool-boiling curve: the relation between heat flux and wall superheat, with nucleate, transition and film-boiling regimes.
• Peak heat flux: the maximum heat flux in nucleate boiling, predicted from hydrodynamic (Taylor) instability.
• Heat pipe: a sealed device that moves heat by evaporation and condensation of a working fluid.

Chapter 10: Radiative heat transfer

• Kirchhoff's law: under suitable conditions emittance equals absorptance.
• View factor: the fraction of radiation leaving one surface that reaches another.
• Gray-body network: an electrical analogy for radiant exchange among diffuse gray surfaces.

Chapter 11: An introduction to mass transfer

• Fick's law: diffusive mass flux is proportional to the gradient of mass fraction in a binary mixture.
• Heat-mass transfer analogy: at low mass-transfer rates, heat transfer correlations can be adapted to mass transfer.
• Stagnant film model: a Couette-flow model used to account for high mass-transfer rates.

Critical Analysis

Strengths

• A clear structure with a built-in minicourse. The preface explains that Chapters 1–3 give a self-contained overview, ending with heat exchanger design, before the detailed study of conduction, convection and radiation. This lets students see why h and view factors matter before spending chapters on them.
• Physical explanation and history. Chapters open with physical pictures and historical episodes—Fourier, Watt and the Newcomen engine, Nukiyama's boiling experiment, Richardson's verse on turbulence—and the text explains the behaviour of boundary layers and boiling regimes in detail rather than only presenting correlations.
• A practical method of dimensional analysis. The authors' method of functional replacement (Chapter 4) is used consistently, giving students one tool for every later problem.
• Extensive, purposeful problems. Each chapter has a long problem set (more than 500 problems in total) with partial answers in brackets, and the preface states that the solutions manual now has more than 520 solved problems; the website links to these solutions. Chapter 1 explains how the problems are meant to build practical calculation, physical insight and analytical skill.

Limitations

• No numerical methods chapter. Chapter 5 notes that direct numerical solution has largely replaced series methods, but the book does not teach finite-difference or finite-element techniques; only occasional problems ask for a numerical solution.
• Prerequisites are real. The preface assumes thermodynamics and fluid mechanics at junior or senior level, and Chapters 6 and 11 use partial differential equations and boundary-layer analysis that will be demanding for weaker students.
• More material than one semester. The preface itself says a one-semester course must exclude some advanced material; boiling, gaseous radiation and multicomponent diffusion are typically beyond a first course.
• Mostly S.I. units. English units appear only in a few problems, which suits most courses but gives limited practice for students who must work in U.S. customary units.

Applications in the Book

Applications run throughout: heat exchanger rating and sizing (Chapter 3), fins on heat exchanger tubing and in biology (Chapter 4), quenching and forging, as in the Samurai-sword example (Chapter 5), laminar pipe flows in micro-electro-mechanical systems and compact exchangers (Chapter 7), condensers (Chapter 8), boilers, evaporators, dropwise condensation and heat pipes (Chapter 9), solar energy and atmospheric radiation (Chapter 10), and cooling towers, dehumidifiers, combustors and evaporation (Chapter 11). Appendix A supplies property data for these calculations.

Where It Fits in the Course

Within the Heat and Mass Transfer list, this book and Nellis and Klein's Introduction to Engineering Heat Transfer are the introductory options, while Çengel and Ghajar's Heat and Mass Transfer, Kreith and Manglik's Principles of Heat Transfer and Bergman, Lavine, Incropera and DeWitt's Fundamentals of Heat and Mass Transfer are fuller engineering texts. These are all broad undergraduate texts by description; the Lienhards' book covers the same core topics (conduction, convection, boiling, radiation, mass transfer) and can serve as the main text for a first course or as a free companion to any of them. Its fuller treatment of boiling and mass transfer, by the evidence of its Chapters 9 and 11, makes it useful even where another book is assigned.

Ghiaasiaan's Convective Heat and Mass Transfer is a specialised, graduate-level next step; students should complete this book's Chapters 6–8 and 11 before moving to it.

How to Use This Book

The book is written for junior and senior engineering students who have taken thermodynamics and fluid mechanics, and it is also intended for self-study. For a one-semester course, cover Chapters 1–3 first, as the authors insist, then Chapter 4 (dimensional analysis and fins), the lumped-capacity and one-dimensional transient sections of Chapter 5, Chapter 6 through the Reynolds-Colburn analogy plus the turbulent results needed for design, Chapter 7, the natural-convection parts of Chapter 8, and Chapter 10. Chapter 10 can be taken at any point after Chapter 2. Chapter 9 and Chapter 11 suit a second course or students with process or energy interests; Chapter 11 does not require Chapters 9 and 10.

Work several problems from each chapter, using the bracketed partial answers to check progress, and use Appendix A for property values. The authors post revised versions on the website, so note the version number on the title-page verso and check for updates.

Edition and Sources

This guide is based on the sixth edition, Version 6.00 dated 19 April 2024 (© 2024 John H. Lienhard V and John H. Lienhard IV, Phlogiston Press), downloaded free from the authors' official site, https://ahtt.mit.edu/, which also links the solutions manual. It draws on the preface (organisation of the book and changes in this edition), the full table of contents, and for all eleven chapters the opening of every section, the chapter summary in Chapter 2, sections 1.4–1.5 in full, and counts and samples of the worked examples and end-of-chapter problems.