Transport Processes in Chemically Reacting Flow Systems

Transport Processes in Chemically Reacting Flow Systems discusses the role, in chemically reacting flow systems, of transport processes-particularly the transport of momentum, energy, and (chemical species) mass in fluids (gases and liquids). The principles developed and often illustrated here for combustion systems are important not only for the rational design and development of engineering equipment (e.g., chemical reactors, heat exchangers, mass exchangers) but also for scientific research involving coupled transport processes and chemical reaction in flow systems.
The book begins with an introduction to transport processes in chemically reactive systems. Separate chapters cover momentum, energy, and mass transport. These chapters develop, state, and exploit useful quantitative ""analogies"" between these transport phenomena, including interrelationships that remain valid even in the presence of homogeneous or heterogeneous chemical reactions. A separate chapter covers the use of transport theory in the systematization and generalization of experimental data on chemically reacting systems. The principles and methods discussed are then applied to the preliminary design of a heat exchanger for extracting power from the products of combustion in a stationary (fossil-fuel-fired) power plant.
The book has been written in such a way as to be accessible to students and practicing scientists whose background has until now been confined to physical chemistry, classical physics, and/or applied mathematics.

Inhalt

List of Primary Figures

List of Primary Tables

Preface

1 Introduction to Transport Processes in Chemically Reactive Systems

Introduction

1.1 Physical Factors Governing Reaction Rates and Pollutant Emission: Examples of Partial or Total "Mixing" Rate Limitations

1.1.1 Flame Spread across IC Engine Cylinder

1.1.2 Gaseous Fuel Jet

1.1.3 Single Fuel Droplet and Fuel Droplet Spray Combustion

1.2 Continuum (vs. Molecular) Viewpoint: Length and Time Scales of Fluid-Dynamic Interest

1.3 Types/Uses of "Control" Volumes

1.4 Notion of Conservation Principles and Their Application to Moving Continua

1.5 Notion of "Constitutive" Laws (and Coefficients) for Particular Substances

1.6 Uses of Conservation/Constitutive Principles in Science and Technology

1.6.1 Inference of Constitutive Laws/Coefficients Based on Analysis and Measurement of Simple ("Canonical") Flow/Transport Situations

1.6.2 Solution of Simpler "Prototype" Problems Illustrating Effects of the Basic Interacting Phenomena

1.6.3 Guide Design of Small-Scale or Full-Scale Experiments, and the Interpretation and Generalization of Experimental Results

1.6.4 Comprehensive Exchanger/Reactor Design Predictions via Computer Modeling

1.6.5 Interpretation of Instrument Measurements Made in the Laboratory or Field

Summary

True/False Questions

References

Bibliography

2 Governing Conservation Principles

Introduction

Approach

2.1 Conservation of Mass

2.1.1 Total Mass Conservation

2.1.2 Individual Species Mass Balance

2.1.3 Individual Chemical Element Conservation

2.2 Conservation of Momentum (Mixture)

2.2.1 Linear Momentum Conservation

2.2.2 Angular Momentum Conservation

2.3 Conservation of Energy (First Law of Thermodynamics)

2.4 "Conservation" of Entropy (Second Law of Thermodynamics)

2.5 Alternative ("Derived") Forms of the Conservation (Balance) Equations

2.5.1 Introduction

2.5.2 Origin of the "Accumulation Rate + Net Convective Outflow Rate" Structure of all Conservation Equations for a Fixed Control Volume

2.5.3 Material Derivative Form of the Conservation PDEs

2.5.4 Alternate Forms of the Energy Conservation PDE

2.5.5 Macroscopic Mechanical Energy Equation (Generalized Bernoulli Equation)

2.5.6 Explicit Form of the Differential Entropy Balance when q'" = 0

2.5.7 Explicit Form of the Conservation PDEs in Alternate Orthogonal Coordinate Systems

2.6 Remarks on Important Generalizations

2.6.1 Moving Control Volumes and "Jump" Conditions across Moving (or Fixed) Discontinuities (Shock Waves, Phase Boundaries, etc.)

2.6.2 Conservation Equations Using an Accelerating (Noninertial) Coordinate Frame

2.6.3 Approach (Reynolds') to Treatment of Turbulence via Time- Averaging the Conservation Equations

2.6.4 Approach to the Treatment of Multiphase Continua via Volume-Averaging the Conservation Equations

2.7 Comments on the Matrix of Fluid Mechanics

2.7.1 Continuum/Molecular

2.7.2 Compressible/Incompressible

2.7.3 Viscous/Inviscid

2.7.4 Newtonian/Non-Newtonian

2.7.5 Steady/Unsteady

2.7.6 Laminar/Turbulent

2.7.7 Multidimensional/One-Dimensional

Summary

True/False Questions

Exercises

References

Bibliography: Conservation Principles

3 Constitutive Laws: The Diffusion Flux Laws and Their Coefficients

3.1 Closure via Constitutive Laws/Coefficients

3.1.1 Equations of State

3.1.2 Chemical Kinetics

3.1.3 Diffusion Flux-Driving Force Laws/Coefficients

3.1.4 General Constraints on the Diffusion Flux Laws

3.2 Linear-Momentum Diffusion (Contact Stress) vs. Rate of Fluid-Parcel Deformation

3.2.1 The "Extra" Stress Operator and Its Components

3.2.2 Stokes' Extra Stress vs. Rate of Deformation Relation

3.2.3 Energy Equation in Terms of the Work Done by the Fluid against the Extra Stress

3.2.4 Viscous Dissipation and Its Consequences

3.2.5 The Dynamic Viscosity Coefficient of Gases and Liquids-Real and Effective

3.3 Energy Diffusion Flux vs. Spatial Gradients of Temperature and Species Concentrat

3.3.1 Fourier's Heat-Flux Law

3.3.2 Species Diffusion Contribution to Energy Flux

3.3.3 Entropy Production and Diffusion Associated with "Fourier" Energy Diffusion

3.3.4 The Thermal Conductivity Coefficient of Gases, Liquids, and Solids-Real and Effective

3.4 Mass Diffusion Flux vs. Spatial Gradients of Composition

3.4.1 Fick's Diffusion-Flux Law for Chemical Species

3.4.2 Corresponding Chemical-Element Diffusion Fluxes

3.4.3 Multicomponent Diffusion Flux Law: Entropy Production and Entropy Diffusion Associated with Chemical Species Diffusion

3.4.4 Solute Diffusivities in Gases, Liquids, and Solids-Real and Effective

3.5 Limitations of Linear Local Flux vs. Local Driving Force Constitutive Laws

3.5.1 "Nonlinear" Fluids

3.5.2 Nonlocal Spatial Behavior

3.5.3 Nonlocal Temporal Behavior-Fluids with Memory

3.5.4 Multiphase Effects: Nonlinear Species "Drag" Laws

Summary

True/False Questions

Exercises

References

Bibliography: Constitutive Laws

4 Momentum Transport Mechanisms; Rates, and Coefficients

4.1 Relevance of Fluid Dynamics and the Classification of Fluid Flow Systems

4.1.1 Role of Fluid Mechanics in the Analysis/Design of Chemical Reactors, Separators, etc.

4.1.2 Criteria for Quiescence

4.1.3 Further Classification of Continuum Fluid Flows

4.1.4 Interactive Role of Experiment and Theory

4.1.5 Overall vs. Local Momentum and Mass Balances

4.2 Mechanisms of Momentum Transport, Their Associated Transport Properties, and Analogies to Energy and Mass Transport

4.2.1 Momentum Convection

4.2.2 Momentum Diffusion

4.2.3 Real and Effective Fluid Viscosities

4.2.4 Analogies to Energy and Mass Transport, and Their Uses

4.3 Convective Momentum Transport in Globally Inviscid Flow

4.3.1 Steady One-Dimensional Compressible Fluid Flow

4.3.2 "Shock" Waves, Sound Waves, Detonation Waves, and "Deflagration" Waves

4.3.3 Rema…