Detonation Initiation from Spontaneous Hotspots Formed During Cook-Off Observed in Molecular Dynamics Simulations
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- 作者：Yanhong Hu ; Donald W. Brenner ; Yunfeng Shi
- 刊名：Journal of Physical Chemistry C
- 出版年：2011
- 出版时间：February 10, 2011
- 年：2011
- 卷：115
- 期：5
- 页码：2416-2422
- 全文大小：935K
- 年卷期：v.115,no.5(February 10, 2011)
- ISSN：1932-7455
文摘
Hotspots that form spontaneously during cook-off (a process in which an explosive is annealed) have been observed in 3D molecular dynamics simulations of a model energetic material. Hotspots that are unable to reach a critical radius of 1.5 nm self-extinguish, whereas hotspots that exceed the critical radius continue to grow with a radial velocity that becomes supersonic. The value of the critical hotspot radius observed in the simulations is in excellent agreement with that predicted from the Frank-Kamenetskii classical initiation theory. The rate of formation of N2, which includes both hot spot nucleation and growth, displays Arrhenius behavior with respect to the initial annealing temperature with an activation energy of 0.5 eV, which is roughly half of that previously determined for thermal decomposition. New equations based on Johnson鈭扢ehl鈭扐vrami鈭扠olmogorov kinetics are proposed for describing the extent of detonated material that could provide new insight into mechanisms of critical hotspot nucleation.