ENCYCLOPEDIA OF EXPLOSIVES AND RELATED ITEMS
1 Introduction 1 11 Background 3 12 What Are We Able to Predict? 5 13 What Are We Unable to Predict? 7 14 Numerical Approaches 9 15 Motivation for This Text 11 16 Purpose of This Book 11 17 Final Word of Caution 13 References 14 2 Transport Phenomena for Nonshock Initiation Processes 15 21 An Overview of Transport Theory in Explosives Problems 15 22 The Origins of Transport Theory in the Field on Nonshock Initiation 19 23 Physical Properties Used in Transport Theory Analysis 22 24 Transport Theory Equations 27 25 Selected Examples of Transport Theory Applied to Explosive Problems 30 26 Summary 41 References 42 3 The Chemical Kinetics of Solid Thermal Explosions 45 31 Introduction 45 32 General Considerations 49 321 Chemical Kinetics and Explosives Modeling 49 322 Types of Models 73 323 Modeling Objectives 76 33 Specific Example: A Global Chemistry Model for HMX 76 331 HMX Thermal Decomposition 77 332 HMX Thermal Ignition 88 333 HMX Thermodynamics 96 334 HMX Thermodynamics and Ignition 103 335 Global Kinetic Models of PBX 9501 (HMX) 109 34 Conclusions 119 References 121 4 Classical Theory of Thermal Criticality 129 41 Introduction 129 411 Spontaneous Combustion 132 412 Thermal versus Physical Explosions 134 413 The Three Fundamental Cookoff Safety Questions 135 414 The Nature of Preignition and Post-Ignition Cookoff Modeling 136 415 Historical Development of Thermal Explosion Theory 137 416 Definition, Scope, and Modern Relevance of Classical Theory 138 417 Emphasis and Outline 139 418 Additional Resources 141 42 Reaction Rate 141 421 Homogeneous and Heterogeneous Chemical Reactions 142 422 Spatial Averaging Over Heterogeneous Solid-Phase Reactants 143 423 The Law of Mass Action 144 424 Arrhenius Reaction Rate 145 425 Reaction Order 146 426 Reaction Rate Expressed as Mass Fraction 147 427 Reaction Progress Function Behavior for Arbitrary Reaction Order 148 428 Zero-Order Reaction versus Negligible Depletion 149 429 Autocatalytic Reactions 150 4210 Hot-Spot-Initiated Reaction 154 4211 Reaction Progress Function for an Ideal Hot-Spot-Initiated Reaction 157 4212 Modeling Complex Thermal Decomposition Behavior 162 4213 The Arrhenius Function and its Calibration 163 4214 Activation Energy as a Measure of HE Sensitivity 165 4215 Thermal Decomposition Parameters for PBX 9501 169 43 Semenov Theory of Criticality 171 431 Volumetric Heat Generation and Surface Heat Loss 171 432 Heat Flux Balance and the Semenov Graphical Construction 172 433 Semenov Criticality Condition 175 434 Explicit Solutions for the Critical Temperatures 177 435 Semenov Universality 180 436 Semenov Steady-State Solution Space 181 44 Semenov Criticality Theory with Reactant Depletion 184 441 The Path to Ignition 184 442 Generalized Semenov Critical State 186 443 Example: First-Order Reaction with Constant Heating Rate 187 444 Behavior of Reaction Runaway Near the Explosion Limit 189 445 Effect of Reaction Energy Content on the Explosion Limit 190 446 Sensitivity to Arrhenius Parameters 192 45 Reactive Heat Equation and the F-K Approximation 192 451 Heat Equation with Volumetric Reaction 193 452 F-K Dimensionless Temperature 194 46 Semenov Theory in the F-K Limit: The “SFK” Model 197 461 Heat Flux Balance, Graphical Construction, Critical Condition 197 462 Criticality Expressed by the Semenov Number 198 463 Explicit Solutions for the Critical Temperatures 199 47 Basic Frank-Kamenetskii Theory 200 471 General Methodology 200 472 Critical Temperature and Critical Size 201 473 Critical Condition for the Infinite Slab 202 474 Critical Condition for the Infinite Cylinder 204 475 Critical Condition for the Sphere 205 476 Critical Temperature Profiles for the Canonical Shapes 207 477 Relative Critical Temperatures for the Canonical Shapes 208 478 F-K Critical State for General Shapes: Square Bar Example 210 48 F-K Criticality Correlations for General Shapes 213 481 Correlation for Bodies of Near-Unity Aspect Ratio 214 482 Comparison of Fkc Values Obtained by Various Studies 217 483 Effective Dimensionality of Near-Unity-Aspect-Ratio Shapes 219 484 Breakdown of the Shape Correlation for Elongated Shapes 220 485 On Extending the Shape Correlation to Elongated Bodies 222 49 F-K Theory with Generalized Boundary Conditions 224 491 Thermal Conductance/Resistance and the Biot Number 224 492 Thomas’ Generalized Boundary Condition 225 493 Infinite Slab: Critical Condition versus Biot Number 226 494 Infinite Cylinder: Critical Condition versus Biot Number 228 495 Sphere: Critical Condition versus Biot Number 230 496 Critical State versus Biot Number for the Canonical Shapes 231 497 Quasi-Self-Similar Scaled Criticality Curves vs Biot Number 233 410 Convergence of the Critical State to the F-K Limit 235 4101 Canonical Shape Criticality for the Full Arrhenius Rate 235 4102 Quasi-Self-Similar Scaled Criticality Curves vs Temperature 237 4103 Critical State Correction for Finite Activation Energy 237 411 Concluding Remarks 239 References 240 5 Deflagration Phenomena in Energetic Materials: An Overview 245 51 Introduction 245 52 Combustion and Its Modes 249 53 The Conductive Deflagration 250 531 A Description of the Conductive Flame Structure 250 532 Factors Affecting the Burn Rate 252 533 Temperature Dependence 253 534 Pressure Dependence 253 535 Quenching and Extinction 257 536 Burning Progression 259 54 Convective Burning 260 541 Gas Flow into Porosity and Isolated Voids 264 542 Ignition of Porosity 266 543 The Influence of a Melt Layer on the Critical Pressure 272 55 Progression of Combustion 273 551 Across Flat Surfaces 274 552 Spreading of Convective Combustion 275 56 Concluding Remarks 284 References 288 6 Mechanical and Thermal Damage 293 61 Introduction 293 62 Classification of Pertinent Morphologies 294 621 Porosity 294 622 Crystal Structure 296 63 Techniques 298 631 Issues of Scale 298 632 The Representative Elementary Volume 298 633 Experimental Methods 299 64 Pristine Materials 309 641 Energetic Material Types 309 642 Examination of Defects in Pure Materials 310 643 Examination of Defects in Pressed Materials 316 644 Examination of Defects in Melt-Cast Materials 317 65 Insult and Damage 317 651 Damage From Mechanical Insult 319 652 Damage From Thermal Insult 337 66 The Effect of Pore Morphology on Fluid Transport in Damaged EM 351 661 Fundamentals of Fluid Transport 352 662 Transport Models 353 663 Experiments with EM Measuring Gas Transport in the Preignition Regime 357 664 Experiments with EM Measuring Gas Transport in the Post-ignition Regime 362 67 Nomenclature 374 References 393 7 Cookoff 403 71 Concept of Critical Temperature 406 711 Semenov’s Approach 408 712 Frank-Kamenetskii’s Approach 412 713 Critical Temperature Determination 413 72 Visual Observation of the Cookoff Event 418 721 Mechanically Confined Cookoff Tests 418 722 Cindy Test 424 73 Small-Scale Instrumented Thermal Ignition Experiments 431 74 Quantification of Reaction Violence 441 741 Experimental 443 742 A First Law Analysis 445 743 Violence 447 744 Energy and Power 449 745 Violence and P2 ? 451 746 Conclusion 459 75 Large, Integrated Experiments 460 751 LLNL Large-Scale Cookoff Test 460 752 Scaled Thermal Explosion Experiment (STEX) 460 753 Large-Scale Annular Cookoff 461 754 Results 463 755 Discussion 471 756 Conclusions 476 76 Final Thoughts 477 References 478 8 The Deflagration-to-Detonation Transition 483 81 Introduction 483 82 Solids 484 821 Solid DDT Phenomenology 486 822 Solid DDT Experimental Evidence 487 83 Type I DDT 489 831 The Phenomenology of Type I DDT 489 832 Experimental Evidence for Type I DDT 494 84 Type II DDT 507 841 Type II DDT Phenomenology 508 842 Experimental Evidence for Type II DDT 511 843 General Discussion of Type II DDT 516 85 The Change Between Type I and Type II DDT 518 851 Experimental Dimension 518 852 Burn Rate 521 853 Porosity, Permeability, and Particle Size Distribution 523 854 Particle Surface Morphology 527 855 Mechanical Properties 528 856 Igniter Effect 528 857 Conclusions 529 86 DDT in Gases, Vapors, and Dust 530 861 Gases and Vapors 530 862 Dusts 531 References 533 9 Friction 537 91 Introduction to Frictional Processes 537 92 Significant Accidents Probably Involving Frictional Processes 537 93 Classical Friction Theory 538 94 Other Factors Affecting Surface Temperatures 540 95 Effects of Particulate Contaminants 541 96 Frictional Processes Involved in Heating and Ignition of Explosives 542 97 Friction Testing Methodology 543 98 Powder Explosive Tests 543 99 Pressed/Cast Explosive Tests 544 991 Oblique Impact Testing Revisited 545 992 LANL Friction Test Apparatus 548 910 Drop-Weight Testing 552 911 Analysis and Modeling 553 References 554 10 Impact and Shear Ignition By Nonshock Mechanisms 555 101 Effects of Shear in Material-Flow Processes 555 102 Drop-Weight Impact Tests 559 1021 Cavendish Laboratory Glass-Anvil 559 1022 Temperature and Flow Sensors 561 103 Large-Scale Crushing Impact 562 1031 IITRI Test 562 1032 Susan Test 566 1033 USS Iowa Explosion 567 1034 XDT Response Mode 568 1035 Two-Step Impacts 570 104 Penetrating Impact of Cased Explosives 571 105 Shear in Confined Charge Assemblies 572 106 Mechanical Properties of Energetic Materials Relevant to Shear Ignition 575 1061 Properties of Unreacted Energetic Materials 575 1062 Mechanical Property Effects on Ignition 575 107 Summary 577 References 578 11 Spark and Laser Ignition 583 111 Introduction 583 112 Spark Detonator: A Vehicle for Study of Loose Powder Response 584 113 Initiation Behavior of Secondary Explosive Spark Detonators 586 114 Similarities Among EBW, Laser, and Spark Initiation of Detonation 587 1141 EBW Detonators 588 1142 Laser Detonators 590 115 Sparks as Sources for Ignition of Explosive Powders 591 1151 Charge Generation and Discharge 591 1152 Electrostatic Discharge (ESD) Sensitivity Testing of Energetic Materials 593 1153 Discharges from Human Body or Handling Equipment 595 116 Electrical Discharges Through High-Density Energetic Materials 596 1161 Conclusions Concerning High-Density Energetic Materials 601 117 Other Laser Applications 602 References 603