Bulletin of the American Physical Society
20th Biennial Conference of the APS Topical Group on Shock Compression of Condensed Matter
Volume 62, Number 9
Sunday–Friday, July 9–14, 2017; St. Louis, Missouri
Session H3: Detonation and Shock-Induced Chemistry: Sub-Detonation Response |
Hide Abstracts |
Chair: Jack Yoh, Seoul National University Room: Grand Ballroom FG |
Tuesday, July 11, 2017 9:15AM - 9:30AM |
H3.00001: Modelling of Deflagration to Detonation Transition in Porous PETN of Density 1.4 g / cc with HERMES John Reaugh, John Curtis, Mary-Ann Maheswaran The modelling of Deflagration to Detonation Transition in explosives is a severe challenge for reactive burn models because of the complexity of the physics; there is mechanical and thermal interaction of the gaseous burn products with the burning porous matrix, with resulting compaction, shock formation and subsequent detonation. Experiments on the explosive PETN show a strong dependence of run distance to detonation on porosity. The minimum run distance appears to occur when the density is approximately 1.4 g / cc. Recent research on the High Explosive Response to Mechanical Stimulation (HERMES) model for High Explosive Violent Reaction has included the development of a model for PETN at 1.4 g / cc., which allows the prediction of the run distance in the experiments for PETN at this density. Detonation and retonation waves as seen in the experiment are evident. The HERMES simulations are analysed to help illuminate the physics occurring in the experiments. JER's work was performed under the auspices of the US DOE by LLNL under Contract DE-AC52-07NA27344 and partially funded by the Joint US DoD/DOE Munitions Technology Development Program. LLNL-ABS-723537 [Preview Abstract] |
Tuesday, July 11, 2017 9:30AM - 9:45AM |
H3.00002: Deflagration to Detonation Transition (DDT) Simulations of HMX Powder Using the HERMES Model Bradley White, John Reaugh, Joseph Tringe We performed computer simulations of DDT experiments [1] with Class I HMX powder using the HERMES model (High Explosive Response to MEchanical Stimulus) in ALE3D. Parameters for the model were fitted to the limited available mechanical property data of the low-density powder, and to the Shock to Detonation Transition (SDT) test results [2]. The DDT tests were carried out in steel-capped polycarbonate tubes. This arrangement permits direct observation of the event using both flash X-ray radiography and high speed camera imaging, and provides a stringent test of the model. We found the calculated detonation transition to be qualitatively similar to experiment. Through simulation we also explored the effects of confinement strength, the HMX particle size distribution and porosity on the computed detonation transition location. [1] Tringe J W, \textit{et al.}, \textit{AIP Conf. Proc.}, \textbf{1793}, 060024 (2017); doi: 10.1063/1.4971580 [2] Garcia F, \textit{et al.}, \textit{J. Phys. Conf. Ser.}, \textbf{500} (2014) 052048. This work was performed under the auspices of the US DOE by LLNL under Contract DE-AC52-07NA27344. [Preview Abstract] |
Tuesday, July 11, 2017 9:45AM - 10:00AM |
H3.00003: Optimizing LX-17 Thermal Decomposition Model Parameters with Evolutionary Algorithms Jason Moore, Matthew McClelland, Craig Tarver, Peter Hsu, H. Keo Springer We investigate and model the cook-off behavior of LX-17 because this knowledge is critical to understanding system response in abnormal thermal environments. Thermal decomposition of LX-17 has been explored in conventional ODTX (One-Dimensional Time-to-eXplosion), PODTX (ODTX with pressure-measurement), TGA (thermogravimetric analysis), and DSC (differential scanning calorimetry) experiments using varied temperature profiles. These experimental data are the basis for developing multiple reaction schemes with coupled mechanics in LLNL’s multi-physics hydrocode, ALE3D (Arbitrary Lagrangian-Eulerian code in 2D and 3D). We employ evolutionary algorithms to optimize reaction rate parameters on high performance computing clusters. Once experimentally validated, this model will be scalable to a number of applications involving LX-17 and can be used to develop more sophisticated experimental methods. Furthermore, the optimization methodology developed herein should be applicable to other high explosive materials. [Preview Abstract] |
Tuesday, July 11, 2017 10:00AM - 10:15AM |
H3.00004: Numerical Simulation of Pre-heated Confined PBX Charge Under Low Velocity. Cai Hu, yanqing wu, Fenglei Huang, Yan liu Impact sensitivity and thermal safety are very important for explosive safety usage.To investigate the effect of thermal softening on impact sensitivity of HMX-based PBX, a finite element model aiming at pre-heated confined PBX charge sbujected to bullets impact has been established. The predicted ignition starting area of the explosive charge was evaluated based on volume strain and equivalent strain contours. It showed that the ignition starting area moves towards the center of the explosives from the surface with increase of heating temperature. The threshold velocity does not increase monotonically with the pre-heating temperature increases. Instead, the threshold velocity rises till 360 m/s when the cook-off temperature is lower than 75${^\circ}$, then decreases the increased temperature. The results imply that our PBX has the lowest impact sensitivity at about 75${^\circ}$. These numerical results agree very well with the corresponding experiment results conducted by Dai et al.. The influence of thermal softening on the impact sensitivity has been analyzed. As the strength decreases, more impact energy will be absorbed. At the same time, shear resistance ability will be weaken and volume compression work may play a more important role to ignition. [Preview Abstract] |
Tuesday, July 11, 2017 10:15AM - 10:30AM |
H3.00005: Abstract Withdrawn
|
Tuesday, July 11, 2017 10:30AM - 10:45AM |
H3.00006: A full scale hydrodynamic simulation of pyrotechnic combustion Bohoon Kim, Seung-gyo Jang, Jack Yoh A full scale hydrodynamic simulation that requires an accurate reproduction of shock-induced detonation was conducted for design of an energetic component system. A series of small scale gap tests and detailed hydrodynamic simulations were used to validate the reactive flow model for predicting the shock propagation in a train configuration and to quantify the shock sensitivity of the energetic materials. The energetic component system is composed of four main components, namely a donor unit (HNS$+$HMX), a bulkhead (STS), an acceptor explosive (RDX), and a propellant (BKNO3) for gas generation. The pressurized gases generated from the burning propellant were purged into a 10 cc release chamber for study of the inherent oscillatory flow induced by the interferences between shock and rarefaction waves. The pressure fluctuations measured from experiment and calculation were investigated to further validate the peculiar peak at specific characteristic frequency ($\omega $c $=$ 8.3 kHz). In this paper, a step-by-step numerical description of detonation of high explosive components, deflagration of propellant component, and deformation of metal component is given in order to facilitate the proper implementation of the outlined formulation into a shock physics code for a full scale hydrodynamic simulation of the energetic component system. [Preview Abstract] |
Follow Us |
Engage
Become an APS Member |
My APS
Renew Membership |
Information for |
About APSThe American Physical Society (APS) is a non-profit membership organization working to advance the knowledge of physics. |
© 2024 American Physical Society
| All rights reserved | Terms of Use
| Contact Us
Headquarters
1 Physics Ellipse, College Park, MD 20740-3844
(301) 209-3200
Editorial Office
100 Motor Pkwy, Suite 110, Hauppauge, NY 11788
(631) 591-4000
Office of Public Affairs
529 14th St NW, Suite 1050, Washington, D.C. 20045-2001
(202) 662-8700