Analysis of Shell Material Influence on Detonation Process in High Explosive Charge

2016 ◽  
Vol 715 ◽  
pp. 27-32 ◽  
Author(s):  
Igor Balagansky ◽  
Alexey Vinogradov ◽  
Lev Merzhievsky ◽  
Alexander Matrosov ◽  
Ivan Stadnichenko
Keyword(s):  
Explosive Charge ◽  
Symmetry Axis ◽  
High Explosive ◽  
Detonation Front ◽  
Detonation Pressure ◽  
Ceramic Shell ◽  
Shell Material ◽  
Detonation Products ◽  
Transverse Waves ◽  
Detonation Process

The influence of the shell material (copper and silicon carbide) on the detonation process in cylindrical high explosive charge is experimentally and numerically investigated. We observed the significant differences of wave pictures in the detonation products and in the shells, which were due to differences in the sound velocities in the shells and rapid destruction of the ceramic shell under explosion loading. The specific features of a wave picture at the interface HE/ceramics due to desensitization of explosive under loading by an advanced wave in the shell were detected. Those features lead to decreasing of detonation pressure, blurring of the detonation front, and to increasing of mass velocity behind detonation front that is typical for under-compressed detonation. On the symmetry axis of HE charge in the ceramic shell behind the detonation front the long zone with practically constant pressure was observed. We have identified the mechanism of transmission of disturbances from the periphery to the symmetry axis of the HE charge. The source of the emergence of this zone is identified as transverse waves propagating directly behind the detonation front from the periphery to the symmetry axis of the HE charge.

The Performance of Pressure Vessel Using Concentric Double Cylindrical High Explosive

2004 ◽  
Vol 126 (4) ◽  
pp. 409-413 ◽  
Author(s):  
Toru Hamada ◽  
Yuichi Nakamura ◽  
Shigeru Itoh
Keyword(s):  
High Velocity ◽  
High Explosive ◽  
Maximum Pressure ◽  
Detonation Pressure ◽  
Low Velocity ◽  
High Explosives ◽  
Detonation Process ◽  
Set Up ◽  
Overdriven Detonation ◽  
Detonation Phenomenon

The detonation pressure from the steady detonation of high explosives is a characteristic. Nevertheless, in materials processing using high explosives, there are cases when the detonation pressure does not match the intended pressure. In this investigation, as a new method of generating the overdriven detonation effectively, a double cylindrical high explosive set up using two kinds of explosives was developed, and its basic performance is analyzed. The concentric double cylindrical high explosive set up was composed of a high velocity explosive and a low velocity explosive, and the overdriven detonation was performed in the low velocity explosive. In this experiment, the ion gap was set up in the high velocity explosive and low velocity explosive respectively, and the detonation velocity was measured. The detonation pressure was also measured by setting up a manganin gauge (Kyowa Electric Instrument Co., Ltd.,) at the position where the generation of the overdriven detonation phenomenon was expected. Furthermore, the overdriven detonation process of the concentric double cylindrical high explosive was continually observed by numerical analysis and the framing photography. From the experimental results, the very high pressure region including the mach stem was observed in the low velocity explosive, and the overdriven detonation phenomenon was confirmed. The maximum pressure value of the concentric double cylindrical high explosive set up was 2.3 times higher than the Chapman-Jouguet pressure of the single explosive.

Interaction of detonation products of a cylindrical high-explosive charge with a surrounding gas

1981 ◽  
Vol 17 (3) ◽  
pp. 344-346
Author(s):  
V. I. Mali ◽  
A. K. Rebrov ◽  
G. A. Khramov ◽  
S. F. Chekmarev
Keyword(s):  
Explosive Charge ◽  
High Explosive ◽  
Detonation Products

Shock-Wave Initiation of a High-Explosive Charge to Create Axially Symmetric Detonation Front

2015 ◽  
Vol 43 (10) ◽  
pp. 3365-3368
Author(s):  
Alexandra Gurinovich ◽  
Pavel Bogdanovich ◽  
Alexander Komorny
Keyword(s):  
Shock Wave ◽  
Explosive Charge ◽  
High Explosive ◽  
Detonation Front ◽  
Axially Symmetric

scholarly journals Melting Point of Carbon Particles behind the Gas Detonation Front

2022 ◽  
Vol 16 (2) ◽  
pp. 59-70
Author(s):  
E. S. Prokhorov
Keyword(s):  
Melting Point ◽  
Detonation Front ◽  
Molar Fraction ◽  
Experimental Studies ◽  
Oxygen Mixture ◽  
Detonation Products ◽  
Gas Detonation ◽  
Nanoscale Particles ◽  
Carbon Particles ◽  
Carbon Condensate

A mathematical model of gas detonation of fuel-enriched mixtures of hydrocarbons with oxygen has been formulated, which makes it possible to numerically study the equilibrium flows of detonation products in the presence of free carbon condensation. Reference data for graphite were used to describe the thermodynamic properties of carbon condensate. The calculations are compared with the known results of experimental studies in which, when detonating an acetylene-oxygen mixture in a pipe closed at one end, it is possible to obtain nanoscale particles from a carbon material with special properties. It is assumed that the melting point of such a material is lower than that of graphite and is about 3100 K. Only with such an adjustment of the melting temperature, the best agreement (with an accuracy of about 3 %) was obtained between the calculated and experimental dependence of the detonation front velocity on the molar fraction of acetylene in the mixture.

Numerical Study of Detonation Propagation in an Insensitive High Explosive Arc with Confinement Materials

2020 ◽  
pp. 2050117
Author(s):  
Yupei Qin ◽  
Kuibang Huang ◽  
Huan Zheng ◽  
Yousheng Zhang ◽  
Xin Yu
Keyword(s):  
Stainless Steel ◽  
Steady State ◽  
Detonation Wave ◽  
High Explosive ◽  
Numerical Study ◽  
Detonation Front ◽  
Outer Boundary ◽  
Outer Part ◽  
Transition Phase ◽  
Detonation Propagation

Detonation propagation in a confined circular arc configuration of an insensitive high explosive PBX9502 is investigated via numerical simulation in this paper. We introduce a steady detonation wave entering the explosive arc with confinements of stainless steel, and then it undergoes a transition phase and reaches a new steady state with a constant angular speed eventually. The influences of the inner and the outer confinements on the propagating detonation wave as well as the characteristics of the detonation driving zone (DDZ) in the steady state are discussed, respectively. Ignition and Growth (I&G) reaction rate and Jones–Wilkins–Lee (JWL) equations of state for the reactants and the products of PBX9502 are employed in the numerical simulations on the basis of a two-dimensional Eulerian code. The equation of state for stainless steel is in the Grüneisen form with a linear shock speed–particle speed Hugoniot relationship. Our results show that the inner confinement dominates the evolution of the detonation wave and the outer confinement only takes effect in a local region near the outer boundary within a limited initial stage during the transition phase. As for the steady state, the existence of the inner confinement makes the DDZ possess a certain width on the inner boundary. While as to the outer part of the detonation wave, the width of the DDZ decreases until the sonic locus intersects with the detonation front shock, which results in the detachment of the DDZ from the outer boundary and makes the detonation propagation fully independent of the outer confinement.

Transformation of Structure in Carbon Steel Specimen under Loading by Mach Stem, Formed in Preliminary Compressed High Explosive Charge TG-40

2011 ◽  
Vol 673 ◽  
pp. 89-94 ◽  
Author(s):  
Ivan A. Bataev ◽  
Igor A. Balagansky ◽  
Anatoly Bataev ◽  
Kazuyuki Hokamoto
Keyword(s):  
Carbon Steel ◽  
Explosive Charge ◽  
High Explosive ◽  
Steel Specimen ◽  
Explosive Loading ◽  
Metallographic Analysis ◽  
Heterogeneous Structure ◽  
Mach Stem ◽  
Localized Deformation ◽  
Current Loading

A structure of a carbon steel specimen after explosive loading is investigated. The loading was executed by Mach stem, formed in high explosive charge that was preliminary compressed by advanced wave in ceramic bar. In the original condition the specimen had a typical for low carbon steel ferrite-pearlite structure. Metallographic analysis has shown that during the process of the explosive loading the following structural changes took place: formation of numerous deformation twins in both ferrite grains and pearlite colonies (i.e. in two-phase structure); formation of extended bands of localized deformation, which are not crystallographically connected with the original ferrite-pearlite structure; fine grains formation in zones of severe plastic flow. The size of the ferrite grains is by an order of magnitude less than the original grains size. According to the authors’ opinion, above-noted structural peculiarities demonstrate that loading conditions achieved in the current loading scheme differ from common. The phenomenon of non-typical twinning in heterogeneous structure (pearlite) indirectly evidences that extremely high stresses and strain rates took place in the specimen during the loading.

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