• Proceedings of the Korean Society of Propulsion Engineers Conference
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• 2008.11a
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• pp.283-287
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• 2008

The heat released during the external frictional motion is a factor responsible for initiating energetic materials under all types of mechanical stimuli including impact, drop, or penetration. We model the friction-induced ignition of HMX, RDX and AP/HTPB propellant using the BAM friction apparatus and one-dimensional time-to-explosion apparatus whose results are used to validate the friction ignition mechanism and the deflagration kinetics of energetic materials, respectively. The ignition times for each energetic sample due to friction are presented.

• Journal of the KSME
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• v.25 no.3
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• pp.209-215
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• 1985

충격파에 의해 폭말물에 일어나는 화학반응 진행현상을 Forest Fire 모델과 함께 고온 부위에 의한 점화와 표면연소자는 현상학적인 근거위에 개발한 모델 두가지(IAG, Sandia)를 설명하였고 이 위에 고온부위 개념에 물리적인 설명을 부여한 새로운 모델을 소개하였다. 나중 세가지 모 델들을 PBX-9404에 대한 여러 가지 실험결과와 비교하였는 바 화학반응 초기의 압력증가현상은 주로 점화항(고온 부위에 의한)에 기인하는 것으로써 모두 만족할만한 결과를 보여주고 있으며 후기의 현상은 실험치와 약간 달라지는것(크거나 혹은 작거나)이 보인다. 이 오차가 과연 어느 만큼 실험 오차이며, 또 어느만큼이 모델 오차인지에 대하여는 아직 자료의 불충분으로 확정지어 말할 수 없다. 예를 들어 그림 4에서는 실험결과가 이론결과 보다 압력을 더 큰 것으로 나타 내고 있으며 그림 5에서는 그 반대 현상을 보인다 앞으로 이 방면에 더 연구가 진행되어야 하 리라고 고려되며 연후에 이 모델들을 다른 폭발물에 적용시켜 일반화시키는 일이 남아 있다.

• Journal of the Korean Society of Propulsion Engineers
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• v.20 no.5
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• pp.19-30
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• 2016

We presented a hydrodynamic modeling necessary to accurately reproduce shock-induced detonation of pyrotechnic initiator. The methodology for such numerical prediction of shock propagation is quite straight forward if the models are properly implemented and solved in a well-formulated shock physics code. A series of SSGT(Small Scale Gap Test) and detailed hydrodynamic simulation are conducted to quantify the shock sensitivity of an acceptor that contains 97.5% RDX. A TBI(Through Bulkhead Initiator) system, consisting of a train configuration of Donor(HNS+HMX) - Bulkhead(STS) - Acceptor(RDX), were investigated to further validate the interaction between energetic and non-reactive materials for predicting the detonating response for successful operation of such small pyro device.

• Journal of the Korean Society of Propulsion Engineers
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• v.20 no.2
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• pp.75-85
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• 2016

A pyrotechnic system consisting of donor/acceptor pair separated by a gap relies on shock attenuation characteristics of the gap material and shock sensitivity of the donor and acceptor charges. Despite of its common use, numerical study of such pyrotechnic train configuration is seldom reported because proper modeling of the full process requires precise capturing of the shock wave attenuation in the gap prior to triggering a full detonation of high explosive and accurate description of the high strain rate dynamics of the explosively loaded inert confinements. We apply a Eulerian level-set based multimaterial hydrocode with reactive flow models for pentolite donor and heavily aluminized RDX as acceptor charge. The complex shock interaction, critical gap thickness, acoustic impedance, and go/no-go characteristics of the gap test are quantitatively investigated.

• Proceedings of the Korea Institutes of Information Security and Cryptology Conference
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• 2006.06a
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• pp.75-78
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• 2006

GF(2)위에서 최대길이를 갖는 n-셀 90/150 셀룰라 오토마타의 각 셀은 길이가 $2^n-1$인 수열을 생성한다. 이러한 셀룰라 오토마타의 임의의 셀에 대한 출력수열은 다른 셀에 대한 출력수열의 위치를 이동함으로써 얻을 수 있다. 본 논문에서는 주어진 셀룰라 오토마타의 상태전이행렬의 특성다항식에 의한 동차 선형점화식을 만족하는 충격반응수열을 이용하여 셀들의 위상이동차를 계산하는 알고리즘을 제안한다.

• Proceedings of the Korea Institute of Fire Science and Engineering Conference
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• 2011.11a
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• pp.466-469
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• 2011

Acrylic Polymer는 충격보강재 및 가공조제 등의 용도로 다양한 산업현장에서 사용되어지고 있는데, 본 제품 제조회사에서 고객사로 제품 납품 후 원료 투입 중 분진폭발이 발생하여 본 위험성평가를 의뢰하였다. 분진의 위험 특성에 대한 분석은 일반적으로 퇴적분진(Dust Layers)와 부유분진(Dust Clouds)으로 구별되어진다. 본 연구에서는 스위스 Kuhner사에서 제작된 분진폭발장치를 이용하여 아크릴 부유분진의 화재.폭발위험성에 대하여 고찰하였다. Acrylic Polymer 부유분진의 폭발위험성은 최대폭발압력 약 6bar, 최대폭발압력상승속도 67 bar/s, Kst 값은 $18m{\cdot}bar/s$로 폭발등급으로 구분하면 St1 [0$bar{\cdot}m/s$]으로 분류되어 "폭발에 의한 위험성이 낮은 분진"에 속하며, 최소점화에너지(MIE)는 300 mJ < MIE < 1,000 mJ로 Normal Sensitivity로서 정전기와 같은 점화원 제거만으로도 어느 정도 충분히 폭발 등을 방지 할 수 있을 것으로 판단된다.

• Proceedings of the Korean Society of Propulsion Engineers Conference
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• 2011.11a
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• pp.981-984
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• 2011

A high-resolution numerical study is carried out to investigate the transient process of the combustion and the shock-train developments in an ethylene-fueled direct-connect dual-mode scramjet combustor. Following the fuel injection, air-throttling is applied at the expansion part of the combustor to provide mass addition to block the flow to subsonic speed. The ignition occurs several ms later when the fuel and air are mixed sufficiently. The pressure build up by the combustion leads to the shock train formation in the isolator section that advances to the exit of the intake nozzle. Then, the air-throttling is deactivated and the exhaust process begins and the situation before the air-throttling is restored. Present simulation shows the detailed processes in the dual-mode scramjet combustor for better understanding of the operation regimes and characteristics.

• Transactions of the Korean Society of Mechanical Engineers B
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• v.38 no.6
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• pp.525-538
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• 2014

Safety of reactive systems is one of the most important research areas in the field of weapon development. A NoGo response or at least a low-order explosion should be ensured to prevent unexpected accidents when the reactive system is impacted by high-velocity projectile. We investigated the shock-induced detonation of cased reactive systems subject to a normal projectile impact to the cylindrical surface based on two-dimensional hydrodynamic simulations using the I&G chemical rate law. Two types of energetic materials, namely LX-17 and AP-based solid propellant, were considered to compare the dynamic responses of the reactive system when subjected to the threshold impact velocity. It was found that shock-to-detonation transition phenomena occurred in the cased LX-17, whereas no full reaction occurred in the propellant.

• Journal of the Society of Disaster Information
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• v.14 no.1
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• pp.89-100
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• 2018

when the explosive wastes to be treated as designated wastes are brought into the wastes treatment plant by mistake and lead to an explosion in the wastes disposal process, many people and property damage are involved. Waste should be treated properly. As mentioned in this paper, ignition reac- tion tests of ignitable re-burning of explosives packing material waste (solid butadiene) confirmed that ignition was easily occurred, and that even small ignition sources were easily ignited and burned quickly and explosively. In particular, when explosives are loaded into incineration wastes in large quantities and mixed with organic compound wastes, such as fire and explosion accidents caused by explosives packing materials at waste disposal sites, flammable and oxidative gases are generated due to mutual oxidation and pyrolysis It is confirmed that there is a possibility that ignition sources such as spark ignite and instantaneously lead to explosion. It is hoped that this study will be a small reference for on - site detection in the field of fire, and it is expected that the fire - fighting agency will be recognized as a fire investigation agency and will contribute to the improvement of the credibility.

• Proceedings of the Korean Society of Propulsion Engineers Conference
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• 2006.05a
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• pp.77-80
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• 2006

Insensitive Munitions(IM) of solid propulsion system are defined as munitions that fulfil the performance and operational requirements, but will minimize the violence of a reaction when subjected to inadvertant stimuli. It should be clear that the reaction violence of rocket motor subjected to thermal stimuli can be mitigated by reducing confinement prior to propellant reaction. Devices designed to do this by venting the rocket motor case are commonly referred to as mitigation devices. The objective of this paper is to introduce the technical information related to the pyrotechnic mitigation devices for insensitive munition of solid rocket motor.