• Title/Summary/Keyword: high explosives

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Modeling of high energy laser heating and ignition of high explosives (고출력 레이저에 의한 가열과 폭약의 점화 모델링)

  • Lee, Kyung-Cheol;Kim, Ki-Hong;Yoh, Jai-Ick
    • Journal of the Korean Society of Propulsion Engineers
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    • v.12 no.3
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    • pp.1-8
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    • 2008
  • We present a model for simulating high energy laser heating of metal for ignition of energetic materials. The model considers effect of ablation of steel plate with long laser pulses and continuous lasers of several kilowatts and the thermal response of well-characterized high explosives for ignition. Since there is enough time for the thermal wave to propagate into the target and to create a region of hot spot in the high explosives, electron thermal diffusion of ultra-short (femto- and pico-second) lasing is ignored; instead, heat diffusion of absorbed laser energy in the solid target is modeled with thermal decomposition kinetic models of high explosives. Numerically simulated pulsed-laser heating of solid target and thermal explosion of RDX, TATB, and HMX are compared to experimental results. The experimental and numerical results are in good agreement.

Numerical Modeling of the Detonation of Explosives Using Hydrodynamics Codes (유체 동역학 코드를 이용한 화약의 폭발과정에 대한 수치 모델링)

  • Park, Dohyun;Choi, Byung-Hee
    • Explosives and Blasting
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    • v.34 no.2
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    • pp.31-38
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    • 2016
  • The hydrodynamics code is a numerical tool developed for modeling high velocity impacts where the materials are assumed to behave like fluids. The hydrodynamics code is widely used for solving impact problems, such as rock blasting using explosives. For a realistic simulation of rock blasting, it is necessary to model explosives numerically so that the interaction problem between rock and explosives can be solved in a fully coupled manner. The equation of state of explosives, which describes the state of the material under given physical conditions, should be established. In this paper, we introduced the hydrodynamics code used for explosion process modeling, the equation of state of explosives, and the determination of associated parameters.

High energy laser heating and ignition study

  • Lee, K.C.;Kim, K.H.;Yoh, J.J.
    • Proceedings of the Korean Society of Propulsion Engineers Conference
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    • 2008.03a
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    • pp.525-530
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    • 2008
  • We present a model for simulating high energy laser heating and ignition of confined energetic materials. The model considers effect of ablation of steel plate with long laser pulses and continuous lasers of several kilowatts and the thermal response of well-characterized high explosives for ignition. Since there is enough time for the thermal wave to propagate into the target and to create a region of hot spot in the high explosives, electron thermal diffusion of ultra-short(femto- and pico-second) lasing is ignored; instead, heat diffusion of absorbed laser energy in the solid target is modeled with thermal decomposition kinetic models of high explosives are used. Numerically simulated pulsed-laser heating of solid target and thermal explosion of cyclotrimethylenetrinitramine(RDX), triaminotrinitrobenzene(TATB), and octahydrotetranitrotetrazine(HMX) are compared to experimental results. The experimental and numerical results are in good agreement.

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A Study Based on Molecular Orbital Theory of Polymerization of Oxolane High Explosives (Oxolane 고폭 화약류의 중합반응에 관한 분자 궤도론적 연구)

  • Kim, Joon-Tae
    • Applied Chemistry for Engineering
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    • v.21 no.3
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    • pp.278-283
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    • 2010
  • The cationic polymerization of oxolane high explosives which have pendant explosive groups such as azido, nitrato and hydrazino is investigated theoretically using the semiempirical MINDO/3, MNDO and AM1 methods. The nucleophilicity and basicity of oxolane high explosives can be explained by the negative charge on oxygen atom of oxolane. The reactivity of propagation in the polymerization of oxolane can be represented by the positive charge on carbon atom and the low LUMO energy of active species of oxolane. The reaction of the oxolane high explosives in oxonium ion form to the open chain carbenium ion form is expected by computational stability energy (17.950~30.197 kcal/mol) of the oxonium ion and carbenium ion favoring the carbenium ion. The relative equilibrium concentration of cyclic oxonium ion and carbenium ion is found to be a major determinant of mechanism, owing to the rapid equilibrium of these catoinic forms. Based on calculation, in the prepolymer propagation step, $S_N1$ mechanism will be at least as fast as that for $S_N2$ mechanism.

A Study on Prevention of Explosion Accidents (폭발재해 예방대책에 관한 소고)

  • Kim In Sung
    • Explosives and Blasting
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    • v.12 no.3
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    • pp.32-41
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    • 1994
  • The specific characters in recent Chemical processing and industrial plants are the handling of severe limit conditions such as high pressure, high and low temperature, high speed production and transportation plant automation and appearance of many new hazardous materials in numbers and quantity. The possibilities of these characters causing the accident and environmental pollution in industrial activities become very high. This paper describes the concrete policy In prevent the explosion accident out of the many accidents which are the safety of the safety engineering.

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A case study of large - long tunnel using the charging mechanization system of the bulk emulsion explosives (Bulk Emulsion 기계화 장전시스템을 이용한 대단면 장대터널 시공사례연구)

  • Yoon, Ji-Sun;Jang, Young-Min;Lee, Sang-Hun
    • Journal of Korean Tunnelling and Underground Space Association
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    • v.11 no.2
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    • pp.107-115
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    • 2009
  • Lately, the length of tunnel, the number of large-long tunnel over three lanes are steeply increased because of the request for high speed and straight road. Therefore, the maximization of excavation efficiency is needed in tunnel construction. Bulk Emulsion explosives charging system is the spearhead equipment using the radio remote control $&$ mechanization system compare with a traditional method Cartridge type. This study introduced the bulk emulsion explosives which is new method in tunnel blasting and verified the efficiency of bulk emulsion explosives for long-large tunnel. And we tried to compare Cartridge type efficiency with bulk emulsion explosives efficiency by the field test.

On the Tunneling technique in Japan (일본의 Tunnel기술)

  • Huh, Ginn
    • Explosives and Blasting
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    • v.12 no.4
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    • pp.10-21
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    • 1994
  • The Tunneling Technique has been developing highly in Japan. Induced NATM pattern is ap-plied as it-self but is an apportunity to upgrade technologes of Concernning. As a result, Nonnel system as Laser marking system is significant developed result. Japan-Korea Tunnel leasing by international High way project is regarded hope-full for the world peace. It has described Euro-Tunnel too.

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Minimum Burning Pressure of Emulsion Explosives (에멀젼폭약의 최소연소압력에 관한 연구)

  • 이승찬;고재순;이영호
    • Explosives and Blasting
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    • v.22 no.3
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    • pp.79-84
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    • 2004
  • It is well accepted that modem emulsion explosives are intrinsically much less sensitive than traditional products such as dynamites or black powder. However, they have still been involved in a significant number of accidental explosions. In October 1975, Canadian Research, Limited's, Energetic Research Laboratory in Quebec exploded. Although explanations for the incident varied, one logical explanation was that the pump used in transporting the emulsion dead headed, thereby turning mechanical work in to frictional heating under a zero flow rate. There is a minimum pressure required for combustion(MBP) to propagate in emulsion explosives. A stable deflagration may lead to a deflagration-to-detonation transition(DDT) in emulsion explosives. Tests were also performed on sensitized sampled consisting of 6 to 21% waters as well as 1 to 11% aluminium powder. It was founded the emulsion explosives consisting of 6% waters had the lowest minimum homing pressure(MBP) of 3 bar, and the 21% waters were unable to achieve sustained homing at pressures as high as 100 bar. The aluminium contained explosives tested here displayed a MBP higher than that of without emulsion. It appears that this test may offer a firm ground for the classification of emulsion explosives in view of the regulating the hazards associated with the various process used for their manufacturing and transport.