Detonation in Shocked Homogeneous High Explosives

Yoo, Choong‐Shik; Holmes, N. C.; Souers, P. C.

doi:10.1557/proc-418-397

Cited by 12 publications

(9 citation statements)

References 20 publications

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“…The shortest-time temperatures we could reliably determine were 3510 ± 220 K for NM at 5 ns and 3470 ± 250 K at 3.5 ns for NM/EDA, so the temperatures were identical within experimental error. These values are quite close to the ∼3600 K values obtained by Yoo and co-workers, − and by Bouyer and co-workers. , …”

Section: Resultssupporting

confidence: 91%

Ethylenediamine Catalyzes Nitromethane Shock-to-Detonation in Two Distinct Ways

2021

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Adding amines to liquid nitromethane (NM) is known to lower the threshold for the shock-to-detonation transition because amines catalyze proton transfer reactions that are the initial steps in the energy release process. We studied NM with 1 wt % ethylenediamine (NM/EDA) with 4 ns input shocks using time and space resolved diagnostics: photon Doppler velocimetry (PDV), optical pyrometry, and nanosecond video imaging. The 4 ns shocks are fast enough to time-resolve the reaction kinetics and the shock-to-detonation transition. We find that it is possible to shock ignite the NM/EDA without producing a detonation, so there is more to amine sensitization of the shock-to-detonation process than simply lowering the barrier to initial reactions. We find that although 1 wt % EDA has little effect on the ambient properties of NM, it dramatically alters the Hugoniot. The shock speed in NM/EDA is reduced, indicating that shocked NM/EDA is significantly more compressible than NM. Higher compressibility is associated with greater adiabatic heating, so EDA both lowers the barrier to proton transfer reactions and increases shock energy absorption. To explain the enhanced compressibility, we propose that shocking NM/EDA produces a reactive flow that has a much higher ionic strength than in NM. The sudden transformation from a molecular liquid to an ionic liquid with stronger intermolecular interactions is responsible for enhanced compressibility and shock heating.

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Section: Resultssupporting

confidence: 91%

Ethylenediamine Catalyzes Nitromethane Shock-to-Detonation in Two Distinct Ways

2021

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“…This means that shocked NM is transparent and we will consider that its absorption coefficient is the same as that for neat NM. Besides, Yoo et al [22] pointed out that shocked NM remains transparent in the spectral range 0.35-0.75 µm. The radiant temperature after shock entrance, prior to the detonation transition, reaches 2500 K. Such a temperature is not in agreement with Chaiken model, which predicts a shock temperature of about 1000 K. It is also clearly greater than those predicted by Lysne and Hardesty [23] (1100-1200 K) or Winey and Gupta [24] (1000 K).…”

Section: Discussionmentioning

confidence: 99%

Shock-to-detonation transition of nitromethane: Time-resolved emission spectroscopy measurements

Bouyer

Darbord

Hervé

et al. 2006

Combustion and Flame

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The objective of this work is to improve the knowledge of the shock-to-detonation transition of nitromethane. The study is based on a spectral analysis in the range 0.3-0.85 µm, with a 28-nm resolution, during experi-ments of plane shock impacts on explosive targets at 8.6 GPa. The time-resolved radiant spectra show that the detonation front, the reaction products produced during the superdetonation, and the detonation products are semitransparent. The temperature and absorption coefficient profiles are determined from the measured spectra by a mathematical inversion method based on the equation of radiative transfer with Rayleigh scattering regime. Shocked nitromethane reaches at least 2500 K, showing the existence of local chemical reactions after shock entrance. Levels of temperature of superdetonation and steady-state detonation are also determined.

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“…Kapila et al investigated the gaseous systems and found that the super detonation develops gradually by an initial weak detonation . Yoo et al classified the shock-induced chemical reaction processes in terms of three steps: First, an unreactive induction period This is followed by a shock initiated chemical reactions period This finally turns into a rapid exothermic reactions period …”

Section: Introductionmentioning

confidence: 99%

Enhancing the Detonation Properties of Liquid Nitromethane by Adding Nitro-Rich Molecule Nitryl Cyanide

et al. 2020

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Nitromethane (NM) is widely used in a variety of industrial applications because of its simple molecular structure and its good combustion and detonation properties. We propose to improve the detonation properties of NM by mixing with the recent synthesized NCNO 2 molecule. We used both ReaxFF reactive molecular dynamics (RMD) and quantum mechanics molecular dynamics (QMMD) to investigate the detonation properties. We find that the 1:1 mixture significantly improve detonation properties including Chapman-Jouguet (CJ) temperature, CJ pressure, and detonation velocity. This is because the number of nitrogen atoms increases the gaseous final products while producing fewer carbon clusters. The detonation properties are also enhanced by the increased initial density leading to higher gas expansion capability. Thus, NCNO 2 is a good additive to NM or a suitable replacement for liquid NM due to its simple molecular structure, huge energy release, and excellent detonation performance under low temperature conditions.

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Detonation in Shocked Homogeneous High Explosives

Cited by 12 publications

References 20 publications

Ethylenediamine Catalyzes Nitromethane Shock-to-Detonation in Two Distinct Ways

Ethylenediamine Catalyzes Nitromethane Shock-to-Detonation in Two Distinct Ways

Shock-to-detonation transition of nitromethane: Time-resolved emission spectroscopy measurements

Enhancing the Detonation Properties of Liquid Nitromethane by Adding Nitro-Rich Molecule Nitryl Cyanide

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