• Title/Summary/Keyword: energetic materials

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Mathematical and Experimental Study for Mixed Energetic Materials Combustion in Closed System

  • Kong, Tae Yeon;Ryu, Byungtae;Ahn, Gilhwan;Im, Do Jin
    • Korean Chemical Engineering Research
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    • v.60 no.2
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    • pp.267-276
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    • 2022
  • Modelling the energy release performance of energetic material combustion in closed systems is of fundamental importance for aerospace and defense application. In particular, to compensate for the disadvantage of the combustion of single energetic material and maximize the benefits, a method of combusting the mixed energetic materials is used. However, since complicated heat transfer occurs when the energetic material is combusted, it is difficult to theoretically predict the combustion performance. Here, we suggest a theoretical model to estimate the energy release performance of mixed energetic material based on the model for the combustion performance of single energetic material. To confirm the effect of parameters on the model, and to gain insights into the combustion characteristics of the energetic material, we studied parameter analysis on the reaction temperature and the characteristic time scales of energy generation and loss. To validate the model, model predictions for mixed energetic materials are compared to experimental results depending on the amount and type of energetic material. The comparison showed little difference in maximum pressure and the reliability of the model was validated. Finally, we hope that the suggested model can predict the energy release performance of single or mixed energetic material for various types of materials, as well as the energetic materials used for validation.

Synthesis of Tetrazole-containing Energetic Copolymers (테트라졸을 포함한 에너지 함유 공중합체의 합성)

  • Shin, Jung-Ah
    • Journal of the Korea Institute of Military Science and Technology
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    • v.14 no.4
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    • pp.726-731
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    • 2011
  • Polymers containing tetrazole groups are very attractive as energetic materials. Copolymer having tetrazole groups could be obtained by 3-steps from commercially available epichlorohydrin. These methods provide a new synthetic pathway to construct polymers containing tetrazole groups from non-energetic polynitrile compounds. These polymers are expected to be good candidates for green and high energetic materials.

Preparation of Energetic Metal Particles and Their Stabilization (에너제틱 금속입자 제조 및 안정화 기술)

  • Lee, Hye Moon;Kim, Kyung Tae;Yang, Sangsun;Yu, Ji-Hun;Kim, Yong-Jin
    • Particle and aerosol research
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    • v.9 no.3
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    • pp.173-185
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    • 2013
  • Oxidations of metal generate large quantity of thermal and light energies but no toxic pollutants, so that metals with high calorific values, such as beryllium, boron, aluminum, magnesium, and lithium, are possible to be used as clean fuels instead of fossil fuels. However, they are so explosive due to very high oxidation rates that they should be stabilized by their surface passivation with oxides, organics and inorganics. For reasonable use of energetic metal particles as solid fuel, therefore, some detail information, such as thermal properties, preparation and passivation methods, and application area, of the energetic metals is introduced in this manuscript.

Development of Explosion Model of Energetic Materials Considering Shock to Detonation Transition and Damage by External Impact (외부 충격에 의한 손상을 고려한 화약과 추진제의 폭발모델 개발)

  • Kim, Bohoon;Yoh, Jai-ick
    • 한국연소학회:학술대회논문집
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    • 2012.11a
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    • pp.97-99
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    • 2012
  • A pressure-based BOIK model considering Shock to Detonation Transition(SDT) and damage due to external fragment or bullet stimuli impact on energetic materials and analytical approach for determination of free parameters are proposed. The rate of product mass fraction(${\lambda}$) consists of ignition term that represents the initiation due to shock compression and growth term that describes propagation of detonation wave and strain term representing the morphological deformation induced by external impact.

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Analytic model to determine the unknown parameters of JWL++ rate equation (JWL++ 반응속도식의 미정상수 결정을 위한 화약의 이론적 모델)

  • Kim, Bohoon;Yoh, Jai-ick
    • 한국연소학회:학술대회논문집
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    • 2012.04a
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    • pp.283-286
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    • 2012
  • The analytical model determining the unknown parameters of reaction rate equation which is necessary to simulate the combustion phenomena of energetic materials is proposed. The relationship between detonation velocity and size effect of energetic materials is derived from simplified JWL++ model. Theoretical model is used to investigate the combustion characteristics of certain energetic materials before running Hydrocode by pre-determination of unknown parameter, b. When b=0.8, the behavior of HANFO gunpowder is in the form of concave-up and ANFO explosives has the concave-down form in case of b=1.5. The analytical model provides efficient and highly accurate results rather than previous method which simulated the unconfined-rate-stick via the numerical means.

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Kinetics analysis of energetic material using isothermal DSC (등온 DSC를 이용한 고에너지 물질의 정밀 반응 모델 기법 개발)

  • Kim, Yoocheon;Park, Jungsu;Kwon, Kuktae;Yoh, Jai-ick
    • 한국연소학회:학술대회논문집
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    • 2015.12a
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    • pp.219-222
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    • 2015
  • The kinetic analysis of energetic materials using Differential Scanning Calorimetry (DSC) is proposed. Friedman Isoconversional method is applied to DSC experiment data and AKTS software is used for analysis. The frequency factor and activation energy are extracted as a function of product mass fraction. The extracted kinetic scheme does not assume multiple chemical steps to describe the response of energetic materials; instead, multiple set of Arrhenius factors are used in describing a single global step. The proposed kinetic scheme has considerable advantage over the standard method based on One-Dimenaionl Time to Explosion (ODTX). Reaction rate and product mass fraction simulation are conducted to validate extracted kinetic scheme. Also a slow cook-off simulation is implemented for validating the applicability of the extracted kinetics scheme to a practical thermal experiment.

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Friction-induced ignition and initiation modeling of HMX, RDX and AP based energetic materials (마찰 하중에 의한 HMX, RDX, AP기반 고에너지물질의 발화특성모델링 연구)

  • Gwak, Min-Cheol;Yoo, Ji-Chang;Yoh, Jai-Ick
    • 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.

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Fabrication and Oxidation Behaviors of Nickel-coated Aluminum Powders for Energetic Applications (에너제틱 응용을 위한 Ni코팅된 Al분말소재 제조 및 산화거동)

  • Kim, Kyung Tae;Woo, Jae Yeol;Yu, Ji Hun;Lee, Hye Moon;Lim, Tae Soo;Choi, Yoon Jeong;Kim, Chang Kee
    • Particle and aerosol research
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    • v.10 no.4
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    • pp.177-182
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    • 2014
  • In this study, nickel-coated aluminum (Ni/Al) powders were synthesized for the utilization of energetic applications. Oxide materials present at the surface of Al powders of $45{\mu}m$ in averaged size were removed by using sodium hydroxide(NaOH) solution which is used for controlling pH. Nickel material is coated into the surface of oxide-removed Al powders by electroless-plating process. The microstructure of fabricated Ni/Al powders shows that nickel layers with a few hundreds nm were very homogeneously formed onto the surface of Al powders. The oxidation behavior of Ni/Al exihibit somewhat faster oxidation rate than that of pure Al with surface oxidation. Also, the higher exothermic reaction was observed from the Ni/Al powders. From the result of this, nickel coating is very promising method to obtain highly reactive and safe Al powders for energetic applications.