# Combustion Science and Engineering

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## Book Description

Students embarking on their studies in chemical, mechanical, aerospace, energy, and environmental engineering will face continually changing combustion problems, such as pollution control and energy efficiency, throughout their careers. Approaching these challenges requires a deep familiarity with the fundamental theory, mathematics, and physical concepts of combustion. Based on more than two decades of teaching experience, **Combustion Science and Engineering** lays the necessary groundwork while using an illustrative, hands-on approach.

Taking a down-to-earth perspective, the book avoids heavy mathematics in the first seven chapters and in Chapter 17 (pollutants formation and destruction), but considers molecular concepts and delves into engineering details. It begins with an outline of thermodynamics; basics of thermochemistry and chemical equilibrium; descriptions of solid, liquid, and gaseous fuels; chemical kinetics and mass transfer; and applications of theory to practical systems. Beginning in chapter 8, the authors provide a detailed treatment of differential forms of conservation equations; analyses of fuel combustion including jet combustion and boundary layer problems; ignition; flame propagation; interactive and group combustion; pollutant formation and control; and turbulent combustion.

In addition, this textbook includes abundant examples, illustrations, and exercises, as well as spreadsheet software in combustion available for download. This software allows students to work out the examples found in the text. **Combustion Science and Engineering** imparts the skills and foundational knowledge necessary for students to successfully approach and solve new problems.

## Table of Contents

Introduction and Review of Thermodynamics

Introduction

Combustion Terminology

Matter and Its Properties

Microscopic Overview of Thermodynamics

Conservation of Mass and Energy and the First Law of Thermodynamics

The Second Law of Thermodynamics

Summary

Stoichiometry and Thermochemistry of Reacting Systems

Introduction

Overall Reactions

Gas Analyses

Global Conservation Equations for Reacting Systems

Thermochemistry

Summary

Appendix

Reaction Direction and Equilibrium

Introduction

Reaction Direction and Chemical Equilibrium

Chemical Equilibrium Relations

Vant Hoff Equation

Adiabatic Flame Temperature with Chemical Equilibrium

Gibbs Minimization Method

Summary

Appendix

Fuels

Introduction

Gaseous Fuels

Liquid Fuels

Solid Fuels

Other Fuels

Size Distributions of Liquid and Solid Fuels

Summary

Appendix

Chemical Kinetics

Introduction

Reaction Rates: Closed and Open Systems

Elementary Reactions and Molecularity

Multiple Reaction Types

Chain Reactions and Reaction Mechanisms

Global Mechanisms for Reactions

Reaction Rate Theory and the Arrhenius Law

Second Law and Global and Backward Reactions

The Partial Equilibrium and Reaction Rate Expression

Timescales for Reaction

Solid–Gas (Heterogeneous) Reactions and Pyrolysis of Solid Fuels

Summary

Appendix

Mass Transfer

Introduction

Heat Transfer and the Fourier Law

Mass Transfer and Fick’s Law

Molecular Theory

Generalized Form of Fourier’s and Fick’s Laws for a Mixture, with Simplifications

Summary

Appendix: Rigorous Derivation for Multicomponent Diffusion

First Law Applications

Introduction

Generalized Relations in Molar Form

Closed-System Combustion

Open Systems

Solid Carbon Combustion

Droplet Burning

Summary

Conservation Relations

Introduction

Simple Diffusive Transport Constitutive Relations

Conservation Equations

Generalized Transport

Simplified Boundary-Layer-Type Problems

Shvab–Zeldovich Formulation

Turbulent Flows

Summary

Appendix

Combustion of Solid Fuels, Carbon, and Char

Introduction

Carbon Reactions

Conservation Equations for a Spherical Particle

Nondimensional Conservation Equations and Boundary Conditions

Interfacial Conservation Equations or BCs

Solutions for Carbon Particle Combustion

Thermal NOx from Burning Carbon Particles

Non-Quasi-Steady Nature of Combustion of Particle

Element Conservation and Carbon Combustion

Porous Char

Summary

Appendix: d Law and Stefan Flow Approximation

Diffusion Flames — Liquid Fuels

Introduction

Evaporation, Combustion, and d^{2} Law

Model/Physical Processes

Governing Equations

Solutions

Convection Effects

Transient and Steady-Combustion Results

Multicomponent-Isolated-Drop Evaporation and Combustion

Summary

Combustion in Boundary Layers

Introduction

Phenomenological Analyses

Generalized Conservation Equations and Boundary Conditions

Interface Boundary Conditions

Generalized Numerical Solution Procedure for BL Equations in Partial Differential Form

Normalized Variables and Conservation Equations

Similarity Solutions–BL Equations

Applications of Generalized Similarity Equations to Various Flow Systems

Solutions for Boundary Layer Combustion of Totally Gasifying Fuels

Combustion Results for Fuels Burning under Convection

Excess Fuel and Excess Air under Convection

Summary

Combustion of Gas Jets

Introduction

Burke–Schumann (B–S) Flame

Modification to B–S Analyses

Laminar Jets

Planar Laminar Jets

Circular Jets

Summary of Solutions for 2-D and Circular Jets

Stoichiometric Contours for 2-D and Circular Jets, Liftoff, and Blow-Off

Jets in Coflowing Air: Jet Flame Structure in Strongly Coflowing Air for 2-D and Circular Jets

Turbulent Diffusion Flames

Partially Premixed Flame

Summary

Ignition and Extinction

Introduction

Modes of Ignition

Ignition of Gas Mixtures in Rigid Systems: Uniform System

Constant-Pressure Systems

Ignition of Solid Particle

Ignition of Nonuniform Temperature Systems—Steady-State Solutions

Summary

Deflagration and Detonation

Introduction

Conservation Equations

Solutions for Rayleigh and Hugoniot Curves

Flame Propagation into Unburned Mixture

Summary

Appendices

Flame Propagation and Flammability Limits

Introduction

Phemenological Analysis

Rigorous Analysis

Flame Stretching

Determination of Flame Velocity

Flammability Limits

Quenching Diameter

Minimum Ignition Energy for Spark Ignition

Stability of Flame in a Premixed Gas Burner

Turbulent Flame Propagation

Summary

Interactive Evaporation and Combustion

Introduction

Simplified Analyses

Arrays and Point Source Method

Combustion of Clouds of Drops and Carbon Particles

Terminology

Governing Equations for Spherical Cloud

Results

Relation between Group Combustion and Drop Array Studies

Interactive Char/Carbon Combustion

Multicomponent Array Evaporation

Summary

Pollutants Formation and Destruction

Introduction

Emission-Level Expressions and Reporting

Effects of Pollutants on Environment and Biological Systems

Pollution Regulations

NOx Sources and Production Mechanisms

NOx Formation Parameters

Stationary Source NOx Control

CO_{2} Sequestration

Carbon Monoxide: CO

SOx Formation and Destruction

Soot

Mercury Emissions

Summary

An Introduction to Turbulent Combustion

Introduction

Turbulence Characteristics

Averaging Techniques

Instantaneous and Average Governing Equations

Governing Differential Equations: Axisymmetric Case and Mixture-Fraction PDF Combustion Model

Turbulent Combustion Modeling (Diffusion Flames)

Probability Density Function

Premixed and Partially Premixed Turbulent Flames: Modeling Approaches

Summary

Appendix I: Cylindrical Coordinate System with Particle-Laden Flow

Problems

Formulae

Appendix A

Appendix B

References

Index

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## Reviews

"There is no doubt regarding the comprehensive coverage of the topic in this book which, I believe, will be well received by the academic and professional communities."

– Gary F. Bennett, Department of Chemical and Environmental Engineering, University of Toledo, in

Journal of Hazardous Materials, 2008