Ignition and Growth Modeling of LX‐17 Hockey Puck Experiments

Tarver, Craig M.

doi:10.1002/prep.200400092

Cited by 57 publications

(53 citation statements)

References 13 publications

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“…Between the reactants and the products, two mixture rules are required as only the total explosive density is known and root finding procedures need to be followed to determine the individual reactants and products densities. Here, the closure conditions chosen are isobaric between the explosive and inert material as it has been proven to give better stability at the interfaces 13 , and isobaric and isothermal between the reactants and products as in similar studies [14][15][16][17] . For more details on aspects of the mathematical model the reader is referred to the work by Michael and Nikiforakis 11 .…”

Section: Mathematical Modelmentioning

confidence: 99%

“…The variation is attributed to the different experiments Rig RG1 RG2 to which the parameters were fitted but also to the particular process that the parameter set intents to model. The parameter data set for the explosive LX-17 used in this study is taken from the work of Tarver 16 and has been used in similar studies 15,17 . The parameters for the JWL EOS are shown in table I and the reaction rate parameters are shown in table II.…”

Section: Data Set and Non-dimensionalizationmentioning

confidence: 99%

“…The parameters for the JWL EOS are shown in table I and the reaction rate parameters are shown in table II. This set is suggested to be more suitable for detonation propagation rather than initiation 16 .…”

Section: Data Set and Non-dimensionalizationmentioning

confidence: 99%

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Detonation propagation in annular arcs of condensed phase explosives

et al. 2017

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We present a numerical study of detonation propagation in unconfined explosive charges shaped as an annular arc (rib). Steady detonation in a straight charge propagates at constant speed but when it enters an annular section, it goes through a transition phase and eventually reaches a new steady state of constant angular velocity. This study examines the speed of the detonation wave along the annular charge during the transition phase and at steady state, as well as its dependence on the dimensions of the annulus. The system is modeled using a recently proposed diffuse-interface formulation which allows for the representation of a twophase explosive and of an additional inert material. The explosive considered is the polymer-bonded TATB-based LX-17 and is modeled using two JWL equations of state and the Ignition and Growth reaction rate law. Results show that steady state speeds are in good agreement with experiment. In the transition phase, the evolution of outer detonation speed deviates from the exponential bounded growth function suggested by previous studies. We propose a new description of the transition phase which consists of two regimes. The first is caused by local effects at the outer edge of the annulus and leads to a dependence of outer detonation speed on angular position along the arc. The second regime is induced by effects originating from the inner edge of the annular charge and leads to the deceleration of the outer detonation until steady state is reached. The study concludes with a parametric study where the dependence of the steady state and the transition phase on the dimensions of the annulus is investigated.

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Section: Mathematical Modelmentioning

confidence: 99%

Section: Data Set and Non-dimensionalizationmentioning

confidence: 99%

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Detonation propagation in annular arcs of condensed phase explosives

et al. 2017

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“…The consequences of microstructural heterogeneity, not reflected in the thermo-mechanical description, are accounted for in an impressionistic way, as we shall see, in the formulation of the reaction rate. Separate JWL equations of state [16] are prescribed for each constituent; the equation of state for the reactant is fitted to the available shock Hugoniot data and the product equation of state to data from cylinder test and other metal acceleration experiments [11]. These equations have the following mechanical and thermal forms.…”

Section: Equations Of Statementioning

confidence: 99%

A study of detonation diffraction in the ignition-and-growth model

Kapila

Schwendeman

Bdzil

et al. 2007

Combustion Theory and Modelling

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Heterogeneous high-energy explosives are morphologically, mechanically and chemically complex. As such, their ab-initio modeling, in which well-characterized phenomena at the scale of the microstructure lead to a rationally homogenized description at the scale of observation, is a subject of active research but not yet a reality. An alternative approach is to construct phenomenological models, in which forms of constitutive behavior are postulated with an eye on the perceived picture of the micro-scale phenomena, and which are strongly linked to experimental calibration. Most prominent among these is the ignition-and-growth model conceived by Lee and Tarver. The model treats the explosive as a homogeneous mixture of two distinct constituents, the unreacted explosive and the products of reaction. To each constituent is assigned an equation of state, and a single reaction-rate law is prescribed for the conversion of the explosive to products. It is assumed that the two constituents are always in pressure and temperature equilibrium.The purpose of this paper is to investigate in detail the behavior of the model in situations where a detonation turns a corner and undergoes diffraction. A set of parameters appropriate for the explosive LX-17 is selected. The model is first examined analytically for steady, planar, 1-D solutions and the reaction-zone structure of Chapman-Jouguet detonations is determined. A computational study of two classes of problems is then undertaken. The first class corresponds to planar, 1-D initiation by an impact, and the second to corner turning and diffraction in planar and axisymmetric geometries. The 1-D initiation, although interesting in its own right, is utilized here as a means for interpretation of the 2-D results. It is found that there are two generic ways in which 1-D detonations are initiated in the model, and that these scenarios play a part in the post-diffraction evolution as well. For the parameter set under study the model shows detonation failure, but only locally and temporarily, and does not generate sustained dead zones. The computations employ adaptive mesh refinement and are finely resolved. Results are obtained for a rigid confinement of the explosive. Compliant confinement represents its own computational challenges and is currently under study. Also under development is an extended ignition-and-growth model which takes into account observed desensitization of heterogeneous explosives by weak shocks.

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“…A great deal of 1D, 2D and 3D experimental data has been used to parameterize detonation models for LX-17 (92.5% TATB plus 7.5% KelF binder) and PBX 9502 (95% TATB plus 5% KelF binder) [2][3][4][5]. Recently several new sets of experimental TATB PBX detonation data have been published.…”

Section: Introductionmentioning

confidence: 99%

Ignition and Growth Modeling of Detonating Tatb Cones and Arcs

Tarver¹,

Chidester²

2008

AIP Conference Proceedings

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Abstract. Previously established Ignition and Growth reactive flow models for the detonating triaminotrinitrobenzene (TATB) based plastic bonded explosives LX-17 and PBX 9502 are applied to recent experimental detonation propagation/failure experiments using unconfined cones, confined arcs, and unconfined arcs. The conical experiments are initially overdriven by the convergent geometry and then fail to detonate at smaller diameters than do unconfined cylindrical charges as the radial rarefaction wave lowers the shock pressure and temperature and thus decreases the chemical energy release rate. Unconfined TATB arcs detonate more slowly than cylindrical charges on the inner surface and exhibit large phase velocities on the outer surface. Confinement reduces but does not eliminate these effects. The Ignition and Growth model calculations based on parameters normalized to a great deal of one-, two-and three-dimensional detonation propagation data reproduce these features and agree closely with experimental detonation velocity and arrival time data.

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Ignition and Growth Modeling of LX‐17 Hockey Puck Experiments

Cited by 57 publications

References 13 publications

Detonation propagation in annular arcs of condensed phase explosives

Detonation propagation in annular arcs of condensed phase explosives

A study of detonation diffraction in the ignition-and-growth model

Ignition and Growth Modeling of Detonating Tatb Cones and Arcs

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