Initiation of nitromethane with relatively long-duration, low-amplitude shock waves

Walker, F.E.; Wasley, Richard J.

doi:10.1016/0010-2180(70)90003-9

Cited by 35 publications

(11 citation statements)

References 7 publications

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“…Nitromethane as a prototypical energetic material has been extensively investigated both in experimental and theoretical studies [1][2][3][4][8][9][10][11][12][13]. Thus, many elaborated experimental measurements and theoretical results are available and used for reference.…”

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confidence: 98%

Calculation of Hugoniot properties for shocked nitromethane based on the improved Tsien’s EOS

2010

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We have calculated the Hugoniot properties of shocked nitromethane based on the improved Tsien's equation of state (EOS) that optimized by "exact" numerical molecular dynamic data at high temperatures and pressures. Comparison of the calculated results of the improved Tsien's EOS with the existed experimental data and the direct simulations show that the behavior of the improved Tsien's EOS is very good in many aspects. Because of its simple analytical form, the improved Tsien's EOS can be prospectively used to study the condensed explosive detonation coupling with chemical reaction.

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confidence: 98%

Calculation of Hugoniot properties for shocked nitromethane based on the improved Tsien’s EOS

2010

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“…Our early studies provided substantial evidence for the acceleration of a non-initiating shock front by the release of a significant amount of energy at or very near the front. We observed initiation in nitromethane at much shorter times (lO-'s versus lo-' s) and by an apparently different mechanism than had been generally presumed (26). We also obtained photographs of the initiation patterns in both homogeneous and heterogeneous explosives at relatively low pressures that suggested new initiation models might be required(26327).…”

Section: The Free-radical Shock Initiation Modelmentioning

confidence: 75%

Quantum Mechanics and Molecular Dynamics Calculations provide new evidence for a free‐radical shock initiation model

Walker

1982

Propellants Explo Pyrotec

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Quantenmechanische und molekular-dynamische Berechnungen liefern einen neuen Beweis fur das Modell der freien Radikale bei Stonziindung Der Unterschied zwischen einem hydrodynamischen Modell fur die StoBziindung von Sprengstoffen und einem neueren mikroskopischen Modell der freien Radikale wird aufgezeigt. Die grundlegende Betrachtungsweise beim Modell der freien Radikale ist, daB die StoBenergie sehr koharent ist und daR diese stark genug ist, den mechanischen Bruch der kovalenten Bindungen herbeizufiihren. Die StoBfront bei der mikroskopischen Betrachtungsweise ist sehr schmal (-5 8, -15 A), ein thermisches Gleichgewicht an der Frontseite existiert nicht. Die freien Atome und Radikale, die gebildet werden in der StoBfront durch Scher-und Beschleunigungskrafte, leiten die chemische Reaktion ein, die zur Entstehung von Hot-spots und zur moglichen Zersetzung des Sprengstoffs fiihrt. Die Geschwindigkeit der Energiefreisetzung und die Schwingungsintensitat der kovalent gebundenen Atome sind Faktoren, die die Detonationsgeschwindigkeit festlegen. Zahlreiche Sprengstoffeigenschaften werden diskutiert, soweit das neue Modell dafijr Erklarungen liefert. Neue Erkenntnisse aus molekular-dynamischen und quantenmechanischen Berechnungen fur StoBwellen in kondensierten Systemen und friihere experimentelle Daten werden zur Stiitzung des Modells der freien Radikale aufgefuhrt. Calculs de mtcanique quantique et de dynamique moltculaire apportant une nouvelle preuve de la validitt du modele des radicaux libres pour I'amorCage par onde de choc On rappelle la difference entre un modele hydrodynamique dtcrivant I'amorGage des explosifs par onde de choc et un modele microscopique plus recent, qui fait appel aux radicaux libres. Dans le modele des radicaux libres on admet essentiellement que I'energie du choc est tres cohtrente et qu'elle suffit pour provoquer la rupture mecanique des liaisons covalentes. A I'tchelle microscopique, le front de choc est tres mince (-5 A -15 A) et il n'existe pas d'equilibre thermique au niveau du front. Les atomes et radicaux libres qui se forment dans le front de choc sous I'effet des forces de cisaillement et d'acceleration, declenchent la reaction chimique qui conduit a I'apparition de points chauds et eventuellement la dtcomposition de la substance explosive. Le taux d'energie libtrte et la frtquence de vibration des atomes B liaison covalente, sont des facteurs qui determinent la vitesse de detonation. A la lumiere des explications quc pcut ci1 Iournir cc nouveau modele, on examine difftrents comportements des explosifs.Pour confirmer le modele des radicaux libres, on fait appel a de nouvelles connaissances acquises dans le domaine des calculs de dynamique moltculaire et de mecanique quantique sur la propagation des ondes de choc dans les milieux condenses. ainsi q u ' i des donnees experimentales anttrieures. SummaryThe contrast between a hydrodynamic model for shock initiation of explosives and a newer microscopic free-radical model is presented. The primary considerations of the free-radical m...

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“…It is worthwhile to compare this physical mecha nism, on which our theoretical explanation [8] of explosive solid state Bridgeman effect transforma tions [9][10][11] was based, with physical kinetics basic to the Walker-Wasley theoretical concept [2,6,7] of det onation propagation in condensed explosives. Such a comparison allows us to draw an analogy between pro cesses at the preparative activation stage inside a pla nar detonation wave shock front and processes that accompany the frontal propagation of the Bridgeman effect inside a pellet.…”

Section: An Analysis Of the Known Resultsmentioning

confidence: 99%

“…The Walker-Wasley theory [2,6,7] constructed to describe shock wave propagation in condensed explo sives is based on a new so called physical kinetics prin ciple. It allows the occurrence of such detonation pro cesses to be explained at the microscopic level.…”

Section: An Analysis Of the Known Resultsmentioning

confidence: 99%

About one analogy for the activation stage of a detonation process in condensed systems

Асланов

2012

Russ. J. Phys. Chem. B

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The modern concepts of detonation processes in condensed systems are analyzed. A theoretical explanation of processes basic to nonthermal explosive solid state transformations at a high pressure sug gested earlier allows a deep analogy between these processes and processes at the activation detonation wave stage that occur inside its shock fore front and in its immediate vicinity to be established.

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Initiation of nitromethane with relatively long-duration, low-amplitude shock waves

Cited by 35 publications

References 7 publications

Calculation of Hugoniot properties for shocked nitromethane based on the improved Tsien’s EOS

Calculation of Hugoniot properties for shocked nitromethane based on the improved Tsien’s EOS

Quantum Mechanics and Molecular Dynamics Calculations provide new evidence for a free‐radical shock initiation model

About one analogy for the activation stage of a detonation process in condensed systems

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