Simulations of Gas Phase Detonations

Simulations of Gas Phase Detonations PDF Author:
Publisher:
ISBN:
Category : Explosions
Languages : en
Pages : 42

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Book Description
Detailed numerical simulations of supersonic reactive flow and gas phase detonation problems are very expensive due to their computer time and memory requirements. The bulk of this cost is in integrating the ordinary differential equations describing chemical reactions. A global induction parameter model has thus been developed which describes the chemical induction time of a mixture and allows for release of energy over a finite time period. The specific gases for which it has been calibrated are stoichiometric mixtures of hydrogen and methane in air. The relatively inexpensive induction parameter model is then used in time-dependent one- and two-dimensional simulations of supersonic reactive flows. (Author).

Simulations of Gas Phase Detonations

Simulations of Gas Phase Detonations PDF Author:
Publisher:
ISBN:
Category : Explosions
Languages : en
Pages : 42

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Book Description
Detailed numerical simulations of supersonic reactive flow and gas phase detonation problems are very expensive due to their computer time and memory requirements. The bulk of this cost is in integrating the ordinary differential equations describing chemical reactions. A global induction parameter model has thus been developed which describes the chemical induction time of a mixture and allows for release of energy over a finite time period. The specific gases for which it has been calibrated are stoichiometric mixtures of hydrogen and methane in air. The relatively inexpensive induction parameter model is then used in time-dependent one- and two-dimensional simulations of supersonic reactive flows. (Author).

Numerical Simulation of Gas-phase Detonation Transmission

Numerical Simulation of Gas-phase Detonation Transmission PDF Author: Elaine S. Oran
Publisher:
ISBN:
Category :
Languages : en
Pages :

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Modeling Explosions and Blast Waves

Modeling Explosions and Blast Waves PDF Author: K. Ramamurthi
Publisher: Springer Nature
ISBN: 3030743381
Category : Technology & Engineering
Languages : en
Pages : 408

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Book Description
b="" The book provides a concise description of the physical processes and mathematical models for explosions and formation of blast waves from explosions. The contents focus on quantitatively determining the energy released in the different types of explosions and the destructive blast waves that are generated. The contribution of flames, detonations and other physical processes to the explosion phenomenon is dealt with in detail. Gaseous and condensed phase explosions are discussed and the yield of explosions with their TNT equivalence is determined. Time scales involved in the explosion process and the scaling procedure are ascertained. Explosions over the ground, in water, and the interaction of explosions with objects are examined. In order to keep the text easily readable, the detailed derivation of the mathematical equations is given in the seven appendices at the end of the book. Case studies of various explosions are investigated and simple problems and their solutions are provided for the different topics to assist the reader in internalizing the explosion process. The book is a useful reference for professionals and academics in aeronautics, mechanical, civil and chemical engineering and for personnel working in explosive manufacture and high-energy materials, armaments, space, defense, and industrial and fire safety.

AMR Code Simulations of Turbulent Combustion in Confined and Unconfined SDF Explosions

AMR Code Simulations of Turbulent Combustion in Confined and Unconfined SDF Explosions PDF Author:
Publisher:
ISBN:
Category :
Languages : en
Pages : 10

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Book Description
A heterogeneous continuum model is proposed to describe the dispersion and combustion of an aluminum particle cloud in an explosion. It combines the gas-dynamic conservation laws for the gas phase with a continuum model for the dispersed phase, as formulated by Nigmatulin. Inter-phase mass, momentum and energy exchange are prescribed by phenomenological models. It incorporates a combustion model based on the mass conservation laws for fuel, air and products; source/sink terms are treated in the fast-chemistry limit appropriate for such gas dynamic fields, along with a model for mass transfer from the particle phase to the gas. The model takes into account both the afterburning of the detonation products of the booster with air, and the combustion of the Al particles with air. The model equations were integrated by high-order Godunov schemes for both the gas and particle phases. Numerical simulations of the explosion fields from 1.5-g Shock-Dispersed-Fuel (SDF) charge in a 6.6 liter calorimeter were used to validate the combustion model. Then the model was applied to 10-kg Al-SDF explosions in a vented two-room structure and in an unconfined height-of-burst explosion. Computed pressure histories are in reasonable (but not perfect) agreement with measured waveforms. Differences are caused by physical-chemical kinetic effects of particle combustion which induce ignition delays in the initial reactive blast wave and quenching of reactions at late times. Current simulations give initial insights into such modeling issues.

A Numerical Study of the Initiation of Cylindrically Symmetric Gas Phase Detonation

A Numerical Study of the Initiation of Cylindrically Symmetric Gas Phase Detonation PDF Author: Bruce Alan Feay
Publisher:
ISBN:
Category : Acoustic phenomena in nature
Languages : en
Pages : 300

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Numerical Simulations of Thermobaric Explosions

Numerical Simulations of Thermobaric Explosions PDF Author:
Publisher:
ISBN:
Category :
Languages : en
Pages : 16

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Book Description
A Model of the energy evolution in thermobaric explosions is presented. It is based on the two-phase formulation: conservation laws for the gas and particle phases along with inter-phase interaction terms. It incorporates a Combustion Model based on the mass conservation laws for fuel, air and products; source/sink terms are treated in the fast-chemistry limit appropriate for such gas dynamic fields. The Model takes into account both the afterburning of the detonation products of the booster with air, and the combustion of the fuel (Al or TNT detonation products) with air. Numerical simulations were performed for 1.5-g thermobaric explosions in five different chambers (volumes ranging from 6.6 to 40 liters and length-to-diameter ratios from 1 to 12.5). Computed pressure waveforms were very similar to measured waveforms in all cases - thereby proving that the Model correctly predicts the energy evolution in such explosions. The computed global fuel consumption?(t) behaved as an exponential life function. Its derivative {dot {mu}}(t) represents the global rate of fuel consumption. It depends on the rate of turbulent mixing which controls the rate of energy release in thermobaric explosions.

Gaseous Detonations

Gaseous Detonations PDF Author: M.A. Nettleton
Publisher: Springer Science & Business Media
ISBN: 9400931492
Category : Medical
Languages : en
Pages : 266

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Book Description
My introduction to the fascinating phenomena associated with detonation waves came through appointments as an external fellow at the Department of Physics, University College of Wales, and at the Department of Mechanical Engineering, University of Leeds. Very special thanks for his accurate guidance through the large body of information on gaseous detonations are due to Professor D. H. Edwards of University College of Wales. Indeed, the onerous task of concisely enumerating the key features of unidimensional theories of detonations was undertaken by him, and Chapter 2 is based on his initial draft. When the text strays to the use of we, it is a deserved acknow ledgement of his contribution. Again, I should like to thank Professor D. Bradley of Leeds University for his enthusiastic encouragement of my efforts at developing a model of the composition limits of detonability through a relationship between run-up distance and composition of the mixture. The text has been prepared in the context of these fellowships, and I am grateful to the Central Electricity Generating Board for its permission to accept these appointments.

A simulation of the fluctuations of international atomic time

A simulation of the fluctuations of international atomic time PDF Author: James Anderson Barnes
Publisher:
ISBN:
Category : Atomic frequency standards
Languages : en
Pages : 72

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Numerical Simulation of Detonation in Condensed Phase Explosives

Numerical Simulation of Detonation in Condensed Phase Explosives PDF Author: D. A. Jones
Publisher:
ISBN:
Category : Blast effect
Languages : en
Pages : 33

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AIAA Journal

AIAA Journal PDF Author: American Institute of Aeronautics and Astronautics
Publisher:
ISBN:
Category : Aeronautics
Languages : en
Pages : 1380

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