Modeling Hydrodynamic Behaviors in Detonation

Abstract

A multistage reaction model developed for general use from initiation through detonation of heterogeneous high explosives is used to specifically simulate the interface vclocimetry and plate push experiments of a triamino‐trinitrobenzene‐based explosive in detonation. A simplification of the unified model leads to a rate relation that ineludes only two dominant stages: a fast one that represents the major portion of reaction dictated by propagation and decomposition, and a slow one that reflects probably the formation of large carbon molecules. The apparent more energetic behavior of the equation of state near the detonation front is actually due to the slow reaction process.

PBX 9502 Products Equation of State

“…We have shown in the past that when the BKW EOS is utilized to simulate the aluminum plate push experiments previously described, the calculation overestimates the experiment in later time, indicating a more energetic condition in the low pressure region since this does not happen when a tantalum plate is used (6). Using the new JWL EOS and the reactive burn model, Fig.…”

Kinetics of electrical conductivity of TATB detonation products as an indicator of growth of carbon nanoparticles

“…It is commonly known that the macrokinetics of energy release in detonating HEs with a high content of carbon (e.g., TNT, TATB, and TNT-RDX mixtures) is characterized by two time scales: fast and slow (see, e.g., [10][11][12]). The fast kinetics is related to disintegration of the initial HE molecules and to formation of stable diatomic and triatomic molecules of detonation products and small carbon clusters (10 to 100 atoms).…”

Prediction of explosive cylinder tests using equations of state from the PANDA code

“…Frost, the predicted detonation properties and cylinder wall velocities for TATB-based explosives show larger discrepancies with experiment than do the other explosives. Some of these discrepancies are clearly due to nonideal behavior, which has been observed in the effect of diameter on detonation velocity [23] [24] and the effect of charge length on the energy imparted to a target [40] - [42]. Second, the velocity histories of thin plates accelerated by LX 14 also show effects due to the reaction zone [21].…”

“…The velocity (or energy) imparted to the target by the explosive is observed to increase with the length of the charge. Tang [42] has shown that these data can be reproduced using a two-step reactive burn model; about 85?40 of the energy is released by a fast reaction, which takes 20 ns, while the rest of the energy is released by a slow reaction that requires an additional 240 ns. The total reaction zone length in Tang's model is about 0.2 cm, which is comparable to the wall thickness in the cylinder tests.…”

“…3.1, TATB-based explosives exhibit nonideal behavior in that the infinite diameter detonation velocity is not attained for charge diameters as large as 13 cm [23] [24]. Nonideal behavior has also been seen in interface velocity and plate-push experiments on TATB explosives [40][41] [42]. The velocity (or energy) imparted to the target by the explosive is observed to increase with the length of the charge.…”