Blast Waves (eBook)

Preface 6
Contents 7
Chapter 1: Introduction 12
Introduction 12
Chapter 2: Some Basic Air Blast Definitions 13
Formation of a Shock Wave 15
Methods for Generating a Shock Wave 16
Chapter 3: The Rankine-Hugoniot Relations 19
Real Air Effects on Gamma 20
Variable gamma Rankine-Hugoniot Relations 21
Some Useful Shock Relations 22
References 25
Chapter 4: Formation of Blast Waves 26
The Taylor Wave 26
The Sedov Solution 27
Rarefaction Waves 29
Nuclear Detonation Blast Standard [7] 32
Description of Blast Wave Formation from a Nuclear Source 32
Description of Energy Deposition and Early Expansion 32
The 1 KT Nuclear Blast Standard 37
Construction of the Fits 42
Overpressure Fit 42
Overdensity Fit 43
Velocity Fit 44
References 45
Chapter 5: Ideal High Explosive Detonation Waves 46
Chapman-Jouget Relations 46
Equation of State 47
Analytic Integration 48
Solid Explosive Detonation 49
TNT Detonation 50
High Explosive Blast Standard 57
Ideal Detonation Waves in Gasses 60
Fuel-Air Explosives 65
Gaseous Fuel-Air Explosives 66
Liquid Fuel Air Explosives 68
Solid Fuel Air Explosives (SFAE) 69
References 72
Chapter 6: Cased Explosives 73
Extremely Light Casings 73
Light Casings 76
Moderate to Heavily Cased Charges 77
Fragmentation 79
Energy Balance 80
Gurney Relations 83
Mott´s Distribution 85
The Modified Fano Equation 88
First Principles Calculation of Blast from Cased Charges 89
Active Cases 90
References 93
Chapter 7: Blast Wave Propagation 94
One Dimensional Propagation 96
Numerical Representations of One Dimensional Flows 98
Two Dimensional Propagation 99
Numerical Representations of Two Dimensional Flows 100
Three Dimensional Propagation 101
Numerical Representations of Three Dimensional Flows 101
Low Overpressure Propagation 103
Acoustic Wave Propagation 104
Non-Linear Acoustic Wave Propagation 106
References 106
Chapter 8: Boundary Layers 107
General Description 107
Boundary Layer Formation and Growth 108
Termination of a Boundary Layer 109
Calculated and Experimental Boundary Layer Comparisons 110
References 119
Chapter 9: Particulate Entrainment and Acceleration 120
Particulate Sweep-up 120
Pressure and Insertion Velocity 121
Drag and Multi-Phase Flow 122
Particulate Effects on Dynamic Pressure 127
Effects of Water 128
References 130
Chapter 10: Instabilities 131
Raleigh-Taylor Instabilities 131
Kelvin-Helmholtz Instabilities 136
Richtmyer-Meshkov Instabilities 139
References 141
Chapter 11: Measurement Techniques 142
Use of Smoke Rockets 142
Smoke Puffs 143
Painted Backdrops 145
Overpressure Measurements 145
Passive Techniques 147
Self Recording Gauges 148
Active Electronic Gauges 149
Density Measurements 150
Velocity Measurement 151
Angle of Flow Measurement 151
Temperature Measurement 152
Dynamic Pressure Measurement 153
Stagnation Pressure Measurement 156
Total Impulse Gauge 157
References 157
Chapter 12: Scaling Blast Parameters 159
Yield Scaling 159
Application to Nuclear Detonations 161
Atmospheric Scaling 163
Examples of Scaling 170
Chapter 13: Blast Wave Reflections 172
Regular Reflections 172
Regular Reflection at Non-perpendicular Incidence 173
Mach Reflection 174
Simple or Single Mach Reflection 174
Complex Mach Reflection 176
Double Mach Reflection 177
Planar Reflections 183
Single Wedge Reflections 183
Pressure Above the Reflecting Surface 187
Mean Free Path Effects 190
Rough Wedge Reflections 193
Reflections from Curved Surfaces 195
References 199
Chapter 14: Height of Burst Effects 201
Ideal Surfaces 201
Nuclear Detonations 203
Solid High Explosive Detonations 205
Range for Mach Transition 216
Height of Burst Over Real Surfaces 218
Surface Response 219
Surface Roughness Effects 222
Dust Scouring Effects 222
Terrain Effects 224
Thermal Interactions (precursors) 227
Free Field Propagation in One Dimension 230
Shock Tube Example 230
Thermal Interactions Over Real Terrain 232
Generating a Heated Layer 233
Organic Surface Material 240
Simulation of Thermal Layers 241
Decursor Simulation 245
References 245
Chapter 15: Structure Interactions 247
Pressure Loads 248
Impulse Loads 251
Non Ideal Blast Wave Loads 254
Negative Phase Effects on Structure Loads 256
Effects of Structures on Propagation 257
The Influence of Rigid and Responding Structures 261
References 269
Chapter 16: External Detonations 270
Chapter 17: Internal Detonations 280
Blast Propagation in Tunnels 286
References 290
Chapter 18: Simulation Techniques 291
Blast Waves in Shock Tubes 291
High Explosive Charges 292
Charge Arrays 294
Use of Exit Jets to Simulate Nuclear Thermal Precursor Blast Environments 296
References 300
Chapter 19: Some Notes on Non-ideal Explosives 301
Properties of Non-ideal Explosives 302
Combustion or Afterburning Dependency of Non-ideal Explosives 302
Charge Size 302
Casing Effects 302
Proximity of Reflecting Surfaces 304
Effects of Venting From the Structure 304
Oxygen Availability 306
Importance of Particle Size Distribution in Thermobarics 308
References 310
Chapter 20: Modeling Blast Waves 311
Non-linear Shock Addition Rules 311
Image Bursts 312
Modeling the Mach Stem 316
Loads from External Sources 318
A Model for Propagating Blast Waves Around Corners 318
Blast Propagation Through an Opening in a Wall 323
Angular Dependence of Transmitted Wave 325
Blast Wave Propagation Through a Second Opening 326
References 328
Index 330