Ignition Sources: Fire, Explosion and Detonation

Preface
Contents
Nomenclature
Greek Symbols
Subscripts
Superscripts
1 Preliminary Concepts and Introduction
1.1 Ignition Sources for Fire, Explosion, and Detonation
1.1.1 Energy Requirements
1.1.2 Fire, Explosion, and Detonation
1.1.3 Fire Triangle
1.1.4 Combustible: Fuel, Oxidizer, Explosive and High-Energy Material
1.1.5 Concentration Limits of Fuel and Oxygen to Form Fire
1.1.6 Confinement of Combustible
1.1.7 Activation Energy and Rate of Heat Release
1.1.8 Magnitudes of Energy Release
1.1.9 Ignition Sources
1.2 Initiation of Chemical Reactions for Fire, Explosion, and Detonation
1.3 Energy for Initiation
1.4 Phonons in the Initiation Process
1.5 Size of Energy Source
1.6 Classification of Ignition Sources
2 Thermal Ignition Energy Sources
2.1 Introduction
2.2 Mechanical Spark
2.2.1 Friction Spark
2.2.2 Sparks During Grinding
2.2.3 Assessment of Energy
2.2.4 Incendiaries and Molten Metal
2.2.5 Energy Content of Spark and Energy Required for Ignition
2.3 Hot Surfaces
2.3.1 Hot Surface and Auto-Ignition
2.3.2 Hot Surfaces from Friction
2.3.3 Solar, Electrical, Radiation, and Space Heating Contributing to Hot Surface
2.3.4 Forced Convection Heat Transfer to Combustibles from Hot Surfaces
2.4 Flame for Ignition
2.4.1 Size of Flame to Start Fire
2.4.2 Size of Candle and Explosions in Coal Mines in the Days of Faraday
2.5 Friction at Surfaces
2.6 Adiabatic Compression
2.7 Shock Compression
2.8 Thermal Initiation by Impact
2.8.1 Low-Velocity Impact
2.8.2 High-Velocity Impact
2.9 Resonant Heating
2.10 Electrical Energy Contributing to Heat
2.10.1 Resistive Heating
2.10.2 Arc Heating
2.10.3 Peltier Heating
3 Chemical Ignition Energy Sources
3.1 Introduction
3.2 Ignition by Catalytic Reactions
3.3 Catalyst Bed as Ignition Source
3.4 Catalysts as Accidental Ignition Sources for Fires and Explosions
3.5 Thermite Reactions as Ignition Sources
3.6 Hypergolic and Pyrophoric Reactions
3.6.1 Pyrophoric Reactions and Difference from Hypergolic Reactions
3.6.2 Hypergolic Liquid Fuels and Oxidizers
3.6.3 Mechanism of Hypergolic Ignition
3.6.4 Other Hypergolic Combinations
4 Electrostatic Ignition Energy Sources
4.1 Introduction: Charges, Discharges, and Energy Release
4.2 Formation of Charges
4.2.1 Contact at Interface
4.2.2 Relative Motion of Interface: Rubbing and Sieving
4.2.3 Inductive Charging
4.2.4 Transfer of Charge
4.2.5 Formation of Charge During Fragmentation and Micronizing
4.2.6 Charge Formation from Piezo-Electric Effect
4.3 Charge and Electric Field
4.4 Ability of Combustible to Retain Charge: Permittivity
4.4.1 Units of Permittivity
4.5 Movement of Charges: Current Density, Mobility, and Specific Electrical Conductivity
4.6 Characteristic Time for Charge to be Retained: Relaxation Time
4.7 Different Types of Discharges
4.8 Breakdown and Paschen's Law
4.9 Charge Accumulation in the Flow of Insulating Liquid and Gaseous Combustibles
4.10 Electrical Discharge from Accumulated Charge in Flow of Combustible
4.11 Streaming Current
4.11.1 Charge Accumulation with Streaming Currents from Multiple Inlets and Outlets
4.12 Charge Accumulation in Humans
4.13 Energy During Discharge
5 Shock Waves as Ignition Sources
5.1 Shock Waves Initiating Detonation
5.2 Objects Moving at Supersonic and Hypersonic Velocities
5.3 Merging of Compression Waves to Form Shocks
5.4 Exploding Wires and Shock Formation
5.5 Exploding Foil and Slapper
6 Electromagnetic Radiation Ignition Sources
6.1 Electromagnetic Waves
6.2 Electromagnetic Spectrum: Energy per Photon
6.2.1 Microwave Heating
6.2.2 Infrared Heating
6.2.3 Heating in Visible and Ultraviolet
6.2.4 X-Rays and Gamma Rays
6.3 Laser and Plasmonic Energy Absorption
7 Ignition Sources for Fire and Explosions in Solid Combustibles
7.1 Solid Fuels and Explosives
7.2 Initiation of Fire and Smolder in Solid Combustibles
7.2.1 Role of Heat Losses in the Initiation of a Fire: Confinement
7.2.2 High-Pressure Heat Dome
7.2.3 Ambient Pressure
7.3 Hypergolic Ignition of Solid Fuel
7.4 Ignition by Mechanical Work
7.5 Ignition of Solid Explosives
7.6 Confinement and Role of Heat Losses in the Ignition of Explosives
7.7 Heated Wire as Ignition Source
7.8 Intrinsic Energy Sources in the Condensed Phase
7.9 Pyrotechnics and Ignition
7.10 Strong and Weak Ignition
7.11 Influence of Confinement
7.12 Partial Confinement and Propellant Ignition
7.12.1 Ignition Source for a Rocket
7.12.2 Full Confinement for Ignition
7.13 Configuration of Ignition Source
7.14 Hang-Fire from Deficient Ignition Source
7.15 Ignition System for a Cartridge
7.16 Ignition Systems for Grenades, Shells, and Mortars
7.17 Thermal Response of Solid Explosives
7.18 Smoldering Transiting to Fire and Explosion: Flashover
7.19 Spontaneous Human Combustion
7.20 Thunderstorms and Lightning Strikes as Ignition Sources for Wild Fires
7.21 Ignition of Solid Fuels and Explosives having Low Melting Temperature
8 Ignition Sources for Detonation of Solid Explosives
8.1 Introduction
8.2 Detonation in Solid Explosives
8.2.1 Chapman–Jouguet, Overdriven, and Low-Velocity Detonation
8.3 Influence of Confinement on Initiation of Detonation
8.4 Initiation of Detonation by Strong Shock Waves
8.4.1 Shock Mach Number Less than the CJ Detonation Mach Number (MS 8.4.2 Shock Mach Number Greater than Mach Number of CJ Detonation (MS>MCJ)
8.4.3 Low-Velocity Detonations
8.5 Detonator as an Ignition Energy Source
8.6 Initiation by Low-Velocity Impact
9 Ignition of Liquid Fuels and Liquid Explosives
9.1 Requirements for Ignition
9.2 Volatile Liquid Fuels
9.3 Ignition Sources for Volatile Liquid Fuels
9.3.1 Formation of Flammable Fuel Vapor–Air Mixture
9.3.2 Ignitability of Volatile Liquid Fuels
9.4 Ignition by Spark
9.4.1 Vaporization and Ignition by Heating
9.4.2 Wicks for Fuel Supply
9.4.3 Wicks for Premixed Fuel–Air Mixture
9.4.4 Vaporization of Droplets and Strong Spark
9.5 Ignition of Non-Volatile Liquid Fuels
9.5.1 Ignition by Hot Compressed Air in a Diesel Engine
9.5.2 Ignition in Ramjets and Scramjet
9.5.3 Ignition of Liquid Propellants in Rockets
9.5.4 Ignition and Popping in Liquid Propellant Rockets
9.5.5 Ignition Sources for Burners and Furnaces Using Heavy Fuel Oils
9.6 Fire and Explosion from Flowing Volatile Liquids by Electrostatic Charges
9.7 Explosion and Detonation of Liquid Explosives from Ingestion of Gas Bubbles
9.7.1 Detonation of Liquid Explosives from Gas Bubbles
9.8 Cavitation as an Ignition Energy Source
10 Ignition Sources for Gaseous Combustibles
10.1 Introduction
10.2 Energy Requirements
10.2.1 Auto-ignition
10.2.2 Influence of Ambient Temperature
10.3 Localized Nature of Ignition: Minimum Ignition Energy
10.3.1 Quenching Thickness
10.3.2 Minimum Ignition Energy
10.4 Initiation of Fire in a Stagnant Combustible Gas Mixture
10.4.1 Stretch and Heat Loss During Ignition of Stagnant Gas
10.4.2 Ignition and Stretch of a Flowing Combustible Gas
10.5 Stretch and Quenching: Requirement of Pilot Flame
10.6 Pilot Ignition of High-Speed Combustible Gas Flow
10.7 Strength of Pilot Energy Source
10.8 Ignition by Hot Surfaces: Steady Flow Model of Yang
10.9 Role of Ignition Energy Sources on Rate of Pressure Rise
10.9.1 Unconfined Space
10.9.2 Confined Space
10.9.3 Hard or Strong Ignition and Weak Ignition Sources
10.9.4 Confinement with Obstructions
10.10 Energy Sources for Detonations: Overdriven, CJ and Low-Velocity Detonations
10.10.1 Energy Requirements
10.11 Example of Ignition Sources Causing Burning and Detonation
11 Unanticipated Thermal Ignition Sources
11.1 Thermal Threat and Insult
11.2 Confinement
11.2.1 Explosive Charges in Confinement
11.3 Fast Cook-off and Slow Cook-off Tests
11.3.1 Fixes for Fast Cook off
11.3.2 Fixes for Slow Cook off
11.4 Volatile Liquid Fuels in Confinement: BLEVE
11.5 Insensitive Explosive Systems
12 Shock Wave and Impact Threats for Confined Solid Explosives
12.1 Introduction
12.2 Nature's Way of Protection Against Adverse Environments
12.3 Shock Sources Causing Detonation: Sympathetic Detonation
12.4 High-Velocity Impact Energy Sources Causing Detonation, Explosion, and Fire
12.4.1 Solid Explosive in Confinement
12.4.2 Solid Explosive with Cavity or Bore
12.4.3 Bore Mitigation for Impact Threats
12.5 Barriers and Coatings
12.6 Relieving Detonation by Modifying Confinement
12.7 Modifying Explosive for Impact and Shock Energy Sources
A Temperature in a Shock Wave Propagating at Constant Velocity
B Acoustic Impedance and Confinement
B.1 Compressibility Coefficient
B.2 Acoustic Impedance and Shock Impedance
B.3 Reflection and Transmission of Pressure Disturbances at Interfaces
C Ignition and Burning of Heavy Fuel Droplets Surrounded by Oxidizing Vapor
C.1 Vaporization Constant λ
C.2 Dependence of Vaporization Constant λ on Fuel Properties: Transport Number
C.3 Vaporization Constant λ and Transport Number
C.3.1 Transport Number for Vaporization of Fuel Droplet in High Temperature Ambient
C.3.2 Transport Number When the Fuel Droplet Burns in an Oxidizing Medium
Index