### Lecture 1: Loud Bang and Disruption

##### Lecture Details :

An Introduction to Explosions and Explosion Safety by Prof. K. Ramamurthi,Department of Mechanical Engineering,IIT Madras.For more details on NPTEL visit http://nptel.ac.in

##### Course Description :

INTRODUCTION: What constitutes an Explosion, Sound Waves, Derivation for Sound Velocity, Steepening of Sound Waves from Impulsive Energy Release, Shock Waves, Loud Noise and Disruption - BLAST WAVES AND EXPLOSIONS: Blast waves and Loud Bang, Isentropic Wave Motion and Non-isentropic Shocks, Examples of Explosions occurring in Nature - Lightning, Volcanic Eruptions, Meteors, Comets and Asteroids, Stellar - TYPICAL EXPLOSIONS: Accidental Explosions Condensed Phase Thermal Explosions, Confined and Unconfined Explosions, Boiling Liquid Expanding Vapor Explosions (BLEVE), Dust Explosions, Physical Explosions, Hazard and Risk - TYPICAL EXPLOSIONS AND CLASSIFICATION: Intentional Explosions Nuclear Explosions, Artillery and Armaments, Improvised Explosive Devices (IED), Constructive uses of Explosions, Implosions, Atmospheric Dispersion- Great Smog of London, Bhopal Gas Tragedy, Classification of Explosions - BLAST WAVE MODELING: Prediction of Blast Wave Strength from Explosions using Buckingham Pi Theorem, Formulation and Analysis, Ideal and Non-ideal Explosions and Blast Waves - BLAST WAVES (Contd.): Summary of Predictions for Blast Wave using Dimensional Analysis, Taylors Prediction for Nuclear Explosions, Non-Dimensional Decay coefficient for a Blast Wave - SHOCK WAVES AND BLAST WAVES: Introduction, Mass, Momentum and Energy conservation Equations across a Shock, Shock Hugoniot, Rayleigh Line - PREDICTIONS FOR SHOCK WAVES: Rankine-Hugoniot Relations, Equations of State, Derivation of Jump in Density and Pressure across a Shock of a given Mach Number, Velocity Prediction behind Shocks in Frame of Reference of Shock and an Inertial Frame of Reference - PREDICTIONS FOR BLAST WAVE: Summary of Pressure, Density, Velocity and Temperature behind Constant Velocity Shocks, Extrapolation of Shock Predictions for Blast Wave, Estimation of pressure, and temperatures in Shocks formed when Meteor entered Atmosphere over Siberian Plains - BLAST WAVE CHARACTERISTICS: Analysis for Concentration of Mass at Blast Wave Front (Snow plow model, Validity of Snow Plow Approximation for Strong Blast Waves, Mechanism of Damage Produced by Blast Wave. Examples with Numerical Predictions - BLAST WAVE PREDICTIONS (Contd.): Overpressure and Impulse from Blast Waves, Explosion Length as a Scaling Parameter, Sachs Scaling, Overpressure from an Ideal Explosion as a Function of Scaled Distance - IMPULSE AND OVERPRESSURE: Side View of Variation of Pressure behind Blast Wave, Impulse from a Blast Wave, Non-dimensional Impulse, Predictions of Non-Dimensional Overpressure and Non-dimensional Impulse for Strong and Weak Blast Waves - SUMMARY OF PREDICTIONS FOR BLAST WAVES: Cranz-Hopkinsons Scaling Laws for Overpressure and Impulse, Missiles and Fragments, Tutorials on Solving Problems in Blast Waves - ENERGY RELEASE: Modeling of Impulsive Energy Release in an Explosion, Moles and Mass, Standard Heats of Formation, Calculation of Energy Release using a Simple Model for Stoichiometric, oxidizer-rich and fuel rich Explosives - ENERGY RELEASE (Contd.): Solving Problems of Energy Release in Fuel-rich and Oxidizer rich Explosives, General Trends.

RATE OF ENERGY RELEASE: Energy Release Rates in a Chemical Reaction, Concentration, Law of Mass Action, Arrhenius Law, Variations of Reaction Rate, Temperature and Concentration in a Chemical Reaction with Time, Role of Activation Energy - THERMAL EXPLOSIONS: Calculation of Heat Release Rates in Typical Chemical Explosions, Dependence on Concentration, Volume and Energy Release Per Unit Mass in a Lumped Mass System, Loss Rates through Heat Transfer, Thermal Theory of Explosions - THERMAL EXPLOSIONS (Contd.): Preheat, auto-ignition and Ignition Energy in the Context of Thermal Theory, Characteristic Heat Loss and Characteristic Heat Release Times, Damkohler Number, Solving Problem of Thermal Explosion in the Worst Industrial Disaster at Texas City - REQUIREMENTS FOR AN EXPLOSION: Role of Induction and Reaction Times in an Explosion, Importance of High Activation Energy, Characteristic Times, Conditions for an Explosion to Occur - FLAMES: Relaxation of Lumped Mass Assumption in Thermal Theory, Ignition, Flame Travel, Burning Velocity and Flame Speed, Estimation of Burning Velocity, Thickness of Flame - FLAMES (Contd.): Laminar and Turbulent Burning Velocities, Quenching Thickness, Peclet number, Davys Safety Lamp, Maximum Experimental Safety Gap, Flame Kernel, Estimation of Ignition Energies - FLAMMABILITY LIMITS: Introduction, Upper and Lower Limits, Estimation and Mechanism, Upward and Downward Flame Propagation and Limits, Minimum Oxygen Concentration and Maximum Safe Oxygen Concentration (MSOC), Solving for MSOC - FLAMMABILITY LIMITS (Contd.): Calculations involving limits, Explosions involving Volatile Liquids, Flash Point Temperature and Fire Point Temperature. Saturation Temperature, Fog, SMOG, Analysis of Explosion of Boeing 747 in TWA 800 Flight.

COMBUSTION WAVES: Introduction, Reaction Hugoniot, Realizable States on the Reaction Hugoniot, Rayleigh Line, Chapman Jouguet Points - DETONATIONS AND DEFLAGRATIONS: Introduction, One Dimensional Theory, Chapman Jouguet Detonation, Zeldovich-von Neuman-Doring Idealized Model of a Detonation, von Neuman Pressure Spike, Pressure, Density and Temperature behind a Detonation- DETONATION: Three Dimensional Mutiheaded Structure of a Detonation, Detonation Cell Size, Modeling of the Initiation of a Detonation, Detonation Kernel like a Flame Kernel, Deflagration to Detonation Transition, Blockages in Flow, Quasi-detonations - FLAMES AND DETONATION: Solving Problems Regarding Flames and Detonations for Propane- Air Explosion at Port Hudson, Missouri and Worlds Largest Man Made Explosion at Ural Mountains, Siberia - GASEOUS EXPLOSIONS: Unconfined, Confined and Partially Confined Gas Explosions, Maximum Pressure and Severity, Role of Blockages, Explosions in Tunnels and Safety, Review of Problems related to Explosion at Falk Corporation at Wisconsin and in Downtown Stockholm - DUST EXPLOSIONS: Introduction, Minimum Explosive Concentration and Dust Particle Size, Estimation of Concentration in Gravity Feed and Forced Feed, Detonation, Smoldering and Secondary Explosions - DUST EXPLOSIONS (Contd.): Solving Problems in Dust Explosions, Severity, Sensitivity, Minimum Ignition Energy and Index of Explosibility of Dust Mixtures, St Classification, Non-volatile Dusts - PHYSICAL EXPLOSIONS: Introduction, Use of Liquid - Vapor Phase Equilibrium for Flash Vaporization, Estimation of Energy Release, Solving Problems - CRYOGENIC EXPLOSIONS AND EXPLOSIONS IN PRESSURE VESSELS: Rollover in Cryogenic Fluid Storage and Physical Explosions, LNG Containers, Explosions in Pressure Vessels, Solving Problems of Pressure Vessel Explosions - CONDENSED PHASE EXPLOSIVES: Introduction, Chemistry of Explosives, Explosives based on Saturated Chains Comprising Straight Chain and Ring Compounds, Alkadienes and Aromatic Compounds, Detonation in Explosives - EXPLOSIVES: Condensed Phase Explosives based on Fulminates, Azides, Acetalide, and Stephnates, Characteristics of condensed Phase Explosives, Enhancement of Energetics, Plastic Explosives, Low, Primary and Secondary Explosives.

TNT EQUIVALENCE AND YIELD: Introduction, Energy and Blast Equivalence, Yield, Problem Solving - ATMOSPHERIC DISPERSION: Introduction, Temperature Inversion, Pasquill Classification of Atmosphere, Dispersion of a Parcel in the Atmosphere, Atmospheric Stability - ATMOSPHERIC DISPERSION (Contd.): Diffusion Equation and Gaussian Solution, Standard Deviation Coefficients, Dispersion in Three Dimensions, Puff and Plume, Dispersion Coefficients, Dispersion of Buoyant and Heavy Gases - ATMOSPHERIC DISPERSION (Contd.): Solving Problems on Dispersion with Specific Reference to Dispersion of Vapor from a Ruptured Pipeline and for the Bhopal Gas Tragedy - DAMAGES FROM EXPLOSIONS: Quantification of Damages to Life and Property, Cumulative Distribution, Dose, Probit and Standard Deviation, Linear Response using Probit, Probit Parameters - RISK ANALYSIS: Introduction, ALARP, Fault Tree and Event Tree Analysis, Gates, Hazop, Other Methods, Problem Solving - SAFETY ASPECTS: Explosion and Fire Safety, Vents and Burst Doors, Maximum Safe Experimental Gap and Critical Size, Ignition Energy, Fire and Explosion Triangle, Accidental Energy Sources.

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