Manner Virginia W, Cawkwell Marc J, Spielvogel Kyle D, Tasker Douglas G, Rose John W, Aloi Michael, Tucker Robert, Moore Jeremiah D, Campbell Maria C, Aslam Tariq D
High Explosives Science & Technology, Los Alamos National Laboratory, Los Alamos, New Mexico 87545, United States.
Theoretical Division, Los Alamos National Laboratory, Los Alamos, New Mexico 87545, United States.
J Am Chem Soc. 2024 Sep 25;146(38):26286-26296. doi: 10.1021/jacs.4c08424. Epub 2024 Sep 11.
We present a new integrated experimental and modeling effort that assesses the intrinsic sensitivity of energetic materials based on their reaction rates. The High Explosive Initiation Time (HEIT) experiment has been developed to provide a rapid assessment of the high-temperature reaction kinetics for the chemical decomposition of explosive materials. This effort is supported theoretically by quantum molecular dynamics (QMD) simulations that depict how different explosives can have vastly different adiabatic induction times at the same temperature. In this work, the ranking of explosive initiation properties between the HEIT experiment and QMD simulations is identical for six different energetic materials, even though they contain a variety of functional groups. We have also determined that the Arrhenius kinetics obtained by QMD simulations for homogeneous explosions connect remarkably well with those obtained from much longer duration one-dimensional time-to-explosion (ODTX) measurements. Kinetic Monte Carlo simulations have been developed to model the coupled heat transport and chemistry of the HEIT experiment to explicitly connect the experimental results with the Arrhenius rates for homogeneous explosions. These results confirm that ignition in the HEIT experiment is heterogeneous, where reactions start at the needle wall and propagate inward at a rate controlled by the thermal diffusivity and energy release. Overall, this work provides the first cohesive experimental and first-principles modeling effort to assess reaction kinetics of explosive chemical decomposition in the subshock regime and will be useful in predictive models needed for safety assessments.
我们展示了一项新的综合实验与建模工作，该工作基于反应速率评估含能材料的固有灵敏度。高爆炸药起爆时间（HEIT）实验已被开发出来，用于快速评估炸药材料化学分解的高温反应动力学。这项工作在理论上得到了量子分子动力学（QMD）模拟的支持，该模拟描绘了不同炸药在相同温度下如何具有截然不同的绝热诱导时间。在这项工作中，对于六种不同的含能材料，HEIT实验和QMD模拟之间的炸药起爆特性排名是相同的，尽管它们包含各种官能团。我们还确定，QMD模拟获得的均匀爆炸的阿伦尼乌斯动力学与从持续时间长得多的一维爆炸时间（ODTX）测量中获得的动力学非常吻合。已经开发了动力学蒙特卡罗模拟来对HEIT实验的耦合热传输和化学过程进行建模，以明确地将实验结果与均匀爆炸的阿伦尼乌斯速率联系起来。这些结果证实，HEIT实验中的点火是不均匀的，反应从针壁开始，并以由热扩散率和能量释放控制的速率向内传播。总体而言，这项工作提供了首次连贯的实验和第一性原理建模工作，以评估亚冲击状态下炸药化学分解的反应动力学，并且将对安全评估所需的预测模型有用。
