Numerical Simulation on Dynamics and Thermal Decomposition of Spallation Polymer Particles Flying in Polymer Ablated Arcs

2015 ◽  
Vol 135 (11) ◽  
pp. 681-687 ◽  
Author(s):  
Takuya Nakagawa ◽  
Tomoyuki Nakano ◽  
Yasunori Tanaka ◽  
Yoshihiko Uesugi ◽  
Tatsuo Ishijima
2019 ◽  
Vol 9 (6) ◽  
pp. 596-603
Author(s):  
Rui Yu ◽  
Shusen Chen ◽  
Guanchao Lan ◽  
Jing Li ◽  
Chenglong Wei ◽  
...  

Thermal stimuli is one of the major external stiumuli resulting from an overheated explosion of a munition. In order to evaluate the influence of external thermal stiumuli on the thermal hazards of JEOL-1 (32 wt% octahydro-1,3,5,7-tetranitro-1,3,5,7-tetrazocine (HMX), 32 wt% 3-nitro-1,2,4-triazole-5-one (NTO), 28 wt% Al and 8 wt% binder system) explosive, accelerating rate calorimeter (ARC) is used to study the adiabatic thermal decomposition properties of JEOL-1 molding powders, and the slow cook-off properties of JEOL-1 are studied by experimental test and numerical simulation. The activation energy Ea, pre-exponential factor A, mechanism function f(α) and self-accelerating decomposition temperature (SADT) of adiabatic thermal decomposition of JEOL-1 molding powders are obtained according to ARC results. The response level of JEOL-1 polymer bonded explosive (PBX) columns exposed to an engulfing liquid pool fire is examined by the slow cook-off test. The ignition location, ignition temperature, ignition time and the transient temperature distributions of JEOL-1 PBX columns during the slow cook-off are obtained by numerical simulation. It can be concluded from this study that JEOL-1 is a low vulnerable explosive with high thermal safety.


2018 ◽  
Vol 669 ◽  
pp. 116-125 ◽  
Author(s):  
Shunyao Wang ◽  
Xu Peng ◽  
Huabo Li ◽  
Zichao Guo ◽  
Liping Chen ◽  
...  

2013 ◽  
Vol 734-737 ◽  
pp. 2116-2119
Author(s):  
Xiang Rong Zhang ◽  
Xu Dan ◽  
Lin Zhou

In order to compare the thermal sensitivity of several typical explosives, this article solved numerically one-dimensional transient heat conduction equation including thermal decomposition for explosives with finite difference method. The explicit difference equations under different boundary conditions were established, and the corresponding stability criterion was derived. The ignition times for typical explosives were calculated, which was used to evaluate thermal sensitivity of explosives.


Author(s):  
William J. Baxter

In this form of electron microscopy, photoelectrons emitted from a metal by ultraviolet radiation are accelerated and imaged onto a fluorescent screen by conventional electron optics. image contrast is determined by spatial variations in the intensity of the photoemission. The dominant source of contrast is due to changes in the photoelectric work function, between surfaces of different crystalline orientation, or different chemical composition. Topographical variations produce a relatively weak contrast due to shadowing and edge effects.Since the photoelectrons originate from the surface layers (e.g. ∼5-10 nm for metals), photoelectron microscopy is surface sensitive. Thus to see the microstructure of a metal the thin layer (∼3 nm) of surface oxide must be removed, either by ion bombardment or by thermal decomposition in the vacuum of the microscope.


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