Computational Fluid Dynamics in Fire Engineering - Theory, Modelling and Practice

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Computational Fluid Dynamics in Fire Engineering: Theory, Modelling and Practice

Copyright

Table of Contents

Preface

Chapter 1: Introduction

1.1 Historical Development of Fire Modeling

1.2 Overview of Current Trends in Fire Modeling

1.3 Review of Major Fire Disasters and Impact on Fire Modeling

1.3.1 Kings Cross Fire

1.3.2 World Trade Center Fire

1.4 Application of Fire Dynamics Tools in Practice

1.5 Validation and Verification of Fire Dynamics Tools

1.6 Scope of the Book

Chapter 2: Field Modeling Approach

Part I Mathematical Equations

2.1 Computational Fluid Dynamics: Brief Introduction

2.2 Computational Fluid Dynamics in Field Modeling

2.3 Equation of State

2.4 Equations of Motion

2.4.1 Continuity Equation

2.4.2 Momentum Equation

2.4.3 Energy Equation

2.4.4 Scalar Equation

2.5 Differential and Integral Forms of the Transport Equations

2.6 Physical Interpretation of Boundary Conditions for Field Modeling

2.7 Numerical Approximations of Transport Equations for Field Modeling

2.7.1 Discretisation Methods

2.7.1.1 Steady Flows

2.7.1.2 Unsteady Flows

2.7.2 Solution Algorithms

2.7.2.1 Matrix Solvers

2.7.2.2 Pressure-Velocity Linkage Methods

2.7.3 Boundary Conditions

2.8 Summary

Part II Turbulence

2.9 What Is Turbulence?

2.10 Overview of Turbulence Modeling Approaches

2.11 Additional Equations for Turbulent Flow-Standard k-epsi Turbulence Model

2.12 Other Turbulence Models

2.12.1 Variant of Standard k-epsi Turbulence Models

2.12.2 Reynolds Stress Models

2.13 Near-Wall Treatments

2.14 Setting Boundary Conditions

2.15 Guidelines for Setting Turbulence Models in Field Modeling

2.16. Worked Examples on the Application of Turbulence Models in Field Modeling

2.16.1 Single-Room Compartment Fire

2.16.2 Influence of Gaps of Fire Resisting Doors on Smoke Spread

2.17 Summary

Chapter 3: Additional Considerations in Field Modeling

Part III Combustion

3.1 Turbulent Combustion in Fires

3.2 Detailed Chemistry versus Simplified Chemistry

3.3 Overview of Combustion Modeling Approaches

3.4 Combustion Models

3.4.1 Generalized Finite-Rate Formulation

3.4.1.1 Background Theory

3.4.1.2 Species Transport Equations

3.4.1.3 Laminar Finite-Rate Chemistry

3.4.1.4 Eddy Break-up and Eddy Dissipation

3.4.2 Combustion Based on Conserved Scalar

3.4.2.1 Description of Approach

3.4.2.2 Definition of Mixture Fraction

3.4.2.3 Flame Sheet Approximation

3.4.2.4 State Relationships

3.4.2.5 Probability Density Function (PDF) of Turbulence-Chemistry

3.4.2.6 Laminar Flamelet Approach

3.5 Guidelines for Selecting Combustion Models in Field Modeling

3.6 Worked Examples on the Application of Combustion Models in Field Modeling

3.6.1 Single-Room Compartment Fire

3.6.2 Two-Room Compartment Fire

3.7 Summary

Part IV Radiation

3.8 Radiation in Fires

3.9 Radiative Transfer Equation

3.10 Radiation Properties of Combustion Products

3.10.1 Gray Gas Assumption

3.10.2 Weighted Sum of Gray Gases Model

3.10.3 Other Models

3.11 Radiation Methods for Field Modeling

3.11.1 Monte Carlo

3.11.2 P-1 Radiation Model

3.11.3 Discrete Transfer Radiative Model

3.11.4 Discrete Ordinates Model

3.11.5 Finite Volume Method

3.12 Guidelines for Selecting Radiation Models in Field Modeling

3.13 Worked Examples on the Application of Radiation Models in Field Modeling

3.13.1 Single-Room Compartment Fire

3.13.2 Two-Room Compartment Fire

3.14 Summary

Chapter 4: Further Considerations in Field Modeling

Part V Soot Production

4.1 Importance of Soot Radiation

4.2 Overview and Limitations of Soot Modeling

4.3 Soot Models for Field Modeling

4.3.1 Single-Step Empirical Rate

4.3.2 Semi-Empirical Approach

4.4 Population Balance Approach to Soot Formation

4.4.1 What Is Population Balance?

4.4.2 Formulation of Transport Equations and Rate Mechanisms

4.5 Guidelines for Selecting Soot Models in Fire Modeling

4.6 Worked Examples on the Application of Soot Models in Field Modeling

4.6.1 Two-Room Compartment Fire

4.6.2 Multi-Room Compartment Fire

4.7 Summary

Part VI Pyrolysis

4.8 Importance of Pyrolysis in Fires

4.9 Phenomenological Understanding of Pyrolysis Processes

4.10 Physico-Chemical Description of Pyrolysis Processes

4.10.1 Pyrolysis of Cellulose

4.10.2 Pyrolysis of Hemicellulose

4.10.3 Pyrolysis of Lignins

4.10.4 Pyrolysis of Wood

4.11 Formulation of Governing Equations

4.11.1 Conservation of Energy for Wood Pyrolysis

4.11.2 Conservation of Mass for Wood Pyrolysis

4.11.3 Modeling Wood Pyrolysis Source Terms

4.11.4 Thermophysical Properties of Wood Pyrolysis

4.12 Practical Guidelines to Pyrolysis Models in Field Modeling

4.13 Worked Example on Ignition of Combustible of Charring Material in a Cone Calorimeter

4.14 Worked Example on Fire Growth and Flame Spread Over Combustible Wall Lining in a Single-Room Compartment

4.15 Summary

Chapter 5: Advance Technique in Field Modeling

5.1 Next Stages of Development and Application

5.2 Alternative Approach to Handling Turbulence

5.2.1 Direct Numerical Simulation (DNS)

5.2.2 Large Eddy Simulation (LES)

5.3 Favre-Averaged Navier-Stokes versus Large Eddy Simulation

5.4 Formulation of Numerical Algorithm

5.4.1 Explicit Predictor-Corrector Scheme

5.4.2 Combustion Modeling

5.4.3 Inclusion of Other Physical Models

5.5 Worked Examples on Large Eddy Simulation Applications

5.5.1 A Freestanding Buoyant Fire

5.5.2 Fire in a Single-room Compartment

5.6 Summary

Chapter 6: Other Challenges in Fire Safety Engineering

6.1 Fire Safety Evaluation and Assessment

6.1.1 Deviation from Prescriptive-Based Statutory Requirements

6.1.2 Adopting Performance-Based Methodologies

6.2 Overview of Emerging Technique in Field Modeling

6.3 Overview of Evacuation Modeling

6.4 Overview of Probabilistic Approach

6.5 Case Studies

6.5.1 The Predictive Capability of Artificial Neural Network Fire Model in a Single-Room Compartment Fire

6.5.2 The Application of CFD-Based Fire Model and Evacuation Model for Fire Safety Evaluation and Assessment

6.6 Future Developments in Fire Predictive and Assessment Models

6.7 Summary

Appendix A: Higher-Order Differencing Schemes and Time-Marching Methods

A.1 Higher-Order Differencing Schemes

A.2 Total Variable Diminishing (TVD) Schemes

A.3 Higher-Order Time-Marching Methods

Appendix B: Algebraic Equation System and CFD-Based Fire Model

B.1 Conversion of Governing Equation to Algebraic Equation System Using the Finite Volume Method

B.2 CFD-Based Fire Model

Appendix C: Advanced Combustion Modeling

C.1 Probability Density Function Method

C.2 Conditional Moment Closure

Appendix D: Relevant Tables for Combustion and Radiation Modeling

References

Further Suggested Reading

Index