A Model for Shock to Detonation Transition in Porous Explosives Via Ramp Loadings

A Model for Shock to Detonation Transition in Porous Explosives Via Ramp Loadings PDF Author: James Richard Stewart
Publisher:
ISBN:
Category :
Languages : en
Pages : 280

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A Model for Shock to Detonation Transition in Porous Explosives Via Ramp Loadings

A Model for Shock to Detonation Transition in Porous Explosives Via Ramp Loadings PDF Author: James Richard Stewart
Publisher:
ISBN:
Category :
Languages : en
Pages : 280

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Prediction of Detonation Transition in Porous Explosives from Rapid Compression Loadings

Prediction of Detonation Transition in Porous Explosives from Rapid Compression Loadings PDF Author:
Publisher:
ISBN:
Category :
Languages : en
Pages : 70

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Book Description
Increasing the nitramine content of solid rocket propellants increases the overall performance of the system as well as the sensitivity to Shock to Detonation Transition (SDT) and Deflagration to Detonation Transition (DDT). This report deals primarily with the analysis and numerical modeling of a combined SDT/DDT event. The results show that in some instances a zone of burning granulated propellant, confined and adjacent to a zone of cast propellant, can provide a rapid enough pressure-rise rate to shock initiate the cast material. This type of detonation hazard scenario is a real possibility in any high-energy rocket motor environment. The modeling study also indicates areas where important assumptions need to be further researched. These include: (a) relations for dynamic (transient) collapse of the voids or pores; (b) relations for setting the volume percent of hot spots based on initial porosity; (c) the evaluation and expression for the chemical rate of decomposition of the reactive, shocked material; and (d) the assessment of two-phase mixture equilibrium. The predicted run-to detonation distance as a function of porosity for HMX explosive compares favorably with limited shock initiation experiments. There is no data available to check whether the predictions of ramp-wave compressions (where rise times exceed several microseconds) presented here are valid.

A Model for Shock Initiation of Porous Explosives by Ramp Induced Compression Processes

A Model for Shock Initiation of Porous Explosives by Ramp Induced Compression Processes PDF Author: Christopher Andrew Cudak
Publisher:
ISBN:
Category :
Languages : en
Pages : 258

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Modeling of Deflagration-to-Shock-to-Detonation Transition (DSDT) in Porous High Energy Solid Propellants and Explosives

Modeling of Deflagration-to-Shock-to-Detonation Transition (DSDT) in Porous High Energy Solid Propellants and Explosives PDF Author: Herman W. Krier
Publisher:
ISBN:
Category :
Languages : en
Pages : 30

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Book Description
This annual report represents the summary of work done on the modeling of processes leading from deflagration to detonation in porous or granular high energy propellants. Particular attention is paid to the analysis of shock development from compression waves forming ahead of confined burning in the original material. It is summarized that if the shock is sufficiently strong, it will lead to shock to detonation transition (SDT). During the development of the shock wave, the porous material may collapse into a solid plug of void free propellant because the speed at which the wave propagates increases as the material is compressed. The modeling effort presented indicates how two-phase unsteady combustion processes in granular material can couple to the solid mechanics of shock formation and eventually to a steady-state detonation. (Author).

Modeling of Deflagration-to-shock-to-detonation Transition (DSDT) in Porous High Energy Solid Propellants and Explosives

Modeling of Deflagration-to-shock-to-detonation Transition (DSDT) in Porous High Energy Solid Propellants and Explosives PDF Author: Herman Krier
Publisher:
ISBN:
Category :
Languages : en
Pages : 25

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Numerical Modeling of the Deflagration-to-detonation Transition

Numerical Modeling of the Deflagration-to-detonation Transition PDF Author:
Publisher:
ISBN:
Category :
Languages : en
Pages :

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Book Description
The effect of a confined porous bed of burning explosive in contact with a solid explosive is studied by computer simulation. The burning is modeled using a bulk burn model that is a function of the surface area and the pressure. Once pressure excursions occur from the confined burning the transition to detonation is modeled using a pressure-dependent heterogeneous explosive shock decomposition model called Forest Fire. The occurrence of detonation in the solid explosive is shown to be dependent upon the surface-to-volume ratio, the confinement of the porous bed, and the geometry of the system.

Scientific and Technical Aerospace Reports

Scientific and Technical Aerospace Reports PDF Author:
Publisher:
ISBN:
Category : Aeronautics
Languages : en
Pages : 1460

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Book Description
Lists citations with abstracts for aerospace related reports obtained from world wide sources and announces documents that have recently been entered into the NASA Scientific and Technical Information Database.

Energy Research Abstracts

Energy Research Abstracts PDF Author:
Publisher:
ISBN:
Category : Power resources
Languages : en
Pages : 756

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Modeling of Shock Development and Transition to Detonation Initiated by Burning in Porous Propellant Beds

Modeling of Shock Development and Transition to Detonation Initiated by Burning in Porous Propellant Beds PDF Author: Patrick Barry Butler
Publisher:
ISBN:
Category :
Languages : en
Pages : 172

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Shock Wave Compression of Condensed Matter

Shock Wave Compression of Condensed Matter PDF Author: Jerry W Forbes
Publisher: Springer Science & Business Media
ISBN: 3642325351
Category : Science
Languages : en
Pages : 388

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Book Description
This book introduces the core concepts of the shock wave physics of condensed matter, taking a continuum mechanics approach to examine liquids and isotropic solids. The text primarily focuses on one-dimensional uniaxial compression in order to show the key features of condensed matter’s response to shock wave loading. The first four chapters are specifically designed to quickly familiarize physical scientists and engineers with how shock waves interact with other shock waves or material boundaries, as well as to allow readers to better understand shock wave literature, use basic data analysis techniques, and design simple 1-D shock wave experiments. This is achieved by first presenting the steady one-dimensional strain conservation laws using shock wave impedance matching, which insures conservation of mass, momentum and energy. Here, the initial emphasis is on the meaning of shock wave and mass velocities in a laboratory coordinate system. An overview of basic experimental techniques for measuring pressure, shock velocity, mass velocity, compression and internal energy of steady 1-D shock waves is then presented. In the second part of the book, more advanced topics are progressively introduced: thermodynamic surfaces are used to describe equilibrium flow behavior, first-order Maxwell solid models are used to describe time-dependent flow behavior, descriptions of detonation shock waves in ideal and non-ideal explosives are provided, and lastly, a select group of current issues in shock wave physics are discussed in the final chapter.