• Journal of Powder Materials
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• v.7 no.1
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• pp.35-41
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• 2000

Al2O3$.$SiC particle was prepared was prepared by the self-propagting high temperature sYthesis(SHS) process from a mixture of SiO2, Al and C powders, The fabricated Al2O3$.$SiC particle was applied to 2024Al/(Al2O3$.$SiC)pcomposite as a reinforcement. Aluminum matix composites were fabricares by the powder extrusion method using the synthesized Al2O3$.$SiC particle and commercial 2024Al powder. Theoptimum preparation conditions for Al2O3$.$SiC partticle by SHS process were described. The influence of the Al2O3$.$SiC voiume fraction on the mechanical was composite was also discussed. Despite adiabatic temperature was about 2367K, SHs reaction was completed not by itself, but by using pre-heating. Mean particle size of final particle synthesized was 0.73 ${\mu}$m and most of the particle was smaller than 2${\mu}$m. Elastic modulus and tensile strength of the composite increased with increase the volume fraction of reinforcement but, tensile strength depreciated at 30 vol% of reinforcement.

• Transactions of the Korean Society of Automotive Engineers
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• v.8 no.5
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• pp.96-104
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• 2000

It is well known that combustion stability under idle and part-load conditions directly affect fuel economy and exhaust emission. In practice, there have been a lot of studies so that a significant improvement in combustion stability has been achieved in this research field. However, applying published results to the development process of mass production engine, there are still many problems which are solved previously. In this study, initial flame behavior and flame propagation characteristic were investigated statistically in order to optimize combustion chamber shapes in the development stage of mass production S.I. engine. To the purpose, the authors applied the flame image capturing system to single cylinder optical engine. The captured flame images were effectively analyzed by using the image processing program which was developed by the authors and adopted new threshold algorithm instead of conventional histogram analysis. In addition, the cylinder pressure was also measured simultaneously to compare evaluated flame results with cylinder pressure data in terms of the combustion characteristics, combustion stability, and cycle-to-cycle combustion variability.

• Korean Journal of Materials Research
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• v.18 no.6
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• pp.313-317
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• 2008

[ $LaFeO_3$ ] powders were synthesized using a method involving solution combustion, and the surface properties of these powders were examined by x-ray photoelectron spectroscopy. As the amount of fuel increased during the synthesis, the $LaFeO_3$ powders became amorphous with a large plate-like shape. It was found that the O 1s spectra were composed of two types of photoelectrons by deconvolutioning the spectra. Photoelectrons with higher binding energy come from adsorbed oxygen ($O^-$) whereas those with lower energy come from lattice oxygen ($O^{2-}$). The ratio of adsorbed and lattice oxygen increased as the ratio of the fuel and nitrate (${\Phi}$) increased. The binding energy of both types of oxygen increased as ${\Phi}$ increased due to the formation of carbonates.

• Transactions of the Korean Society of Automotive Engineers
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• v.12 no.6
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• pp.46-53
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• 2004

Heat release analysis is a very important method for understanding the combustion phenomena inside an engine cylinder. In this study, one-zone heat release analysis was used with the measured cylinder pressures of a HSDI(high speed direct injection) and IDI(indirect injection) diesel engines, Those have benefits of simple equation, fast speed, reliability. The objective of the study is to compare the combustion characteristics between a HSDI and an IDI. The result shoes that the maximum heat release rate of a HSDI is higher than that of an IDI because of long ignition delay period. The heat release curve of an IDI is more linear than that of a HSDI, thus is similiar to that of a SI engine. The combustion efficiency of a HSDI is higher than that of an IDI because of the smaller heat transfer loss of a HSDI. There is a suggestion here that an IDI engine has broad heat transfer area which include two combustion chambers, the connection passage of combustion chambers, etc.

• JOURNAL OF ELECTRICAL WORLD
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• s.301
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• pp.68-73
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• 2002

미쓰비시(삼릉)전기는 1999년 5월치바현 이치가와시 동빈에$''$특정가정용기기재상품화법(통칭 : 가전리사이클법)$''$에 대응하기 위하여 일본국내 최초의 전기제품 리사이클 플랜트를 가동시켰다. 이 플랜트에서는 종합전기메이커로서의 특징을 살려 연소를 수반하지 않는 철저한 머티어리얼 리사이클, 물을 쓰지 않는 완전건식에 의한 소재(素材)의 분리$\cdot$분별(分別)을 실현하였다. 최대의 특징은 수(手)작업에 의한 부분분해와 기계분해(파쇄에 의한 소재분리)를, 리사이클률, 경제성, 환경부하성의 3가지 관점에서 조화를 시키고 있는 점이다. 본고에서는 리사이클 플랜트의 개요를 소개하고 리사이클률 향상과 리사이클 처리비용 저감을 위해 대처해 온 다음의 3개 항목에 대하여 기술한다. (1) 플라스틱찌꺼기(殘材) 리사이클설비의 개발 주파쇄분리(主破碎分離) 프로세스에서 배출되는 금속과 염화비닐을 포함한 플라스틱찌꺼기를 처리하여, 플라스틱을 고로환원재(高爐還元材)로서 유효 활용할 수 있도록 하였다. (2)효율적인 물류(物流)레이아웃 및 수해체방식(手解體方式)의 설계 공장내의 폐제품(廢製品)$\cdot$분별물(分別物)에 대한 보관장소, 반송수단$\cdot$경로를 최적 설계하여 처리비용을 요하는 수해체 작업을 효율적으로 할 수 있도록 업무흐름을 설계하였다. (3)리사이클공장 관리시스템의 구축 공장관리의 효율화와 배출자(排出者)에 대한 리사이클정보가 분명하게 나타날 수 있게 하기 위하여 리사이클공장관리시스템을 개발하여 도입하였다.

• Proceedings of the Korean Society of Propulsion Engineers Conference
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• 2010.11a
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• pp.261-264
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• 2010

Dual Pulse Rocket Motor is a solid rocket motor with two grains separated by a bulkhead and rupture disc. The elasto-plastic explicit dynamic analysis of rupture disc was conducted by the finite element method. The effect of the slit geometry of rupture disc with radial slit was parametrically analyzed in terms of rupture time and shape. The results can be used to control the rupture pressure by changing the slit geometry of rupture disc.

• Journal of the Korean Society of Propulsion Engineers
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• v.5 no.3
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• pp.79-86
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• 2001

The six-components force measurements systems for rocket motors are used to measure multi components force generated by TVC(Thrust Vector Control) motors. This paper suggested the modeling scheme which is used in preliminary design and test analysis procedure and which can be applied to the existing other test stand in operation. The model whose parameters are determined by least square method makes the design engineer build the test stand to satisfy all kinds of requirements such as accuracy, operating condition and structural stability without tradeoff among the requirements. The experimental results shows that the proposed model has better accurate performances than those of other existing model.

• Proceedings of the Korean Society of Propulsion Engineers Conference
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• 2010.05a
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• pp.105-112
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• 2010

Dual Pulse Rocket Motor is a solid rocket motor with two grains separated by a bulkhead and rupture disc. The elasto-plastic explicit dynamic analysis of rupture disc was conducted by finite element method. The effect of the slit geometry of a rupture disc was analyzed for rupture time and shape by the parametric study. The results can be used to control the rupture pressure by the change the slit geometry of a rupture disc.

• Journal of the Korean Society of Propulsion Engineers
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• v.17 no.6
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• pp.38-47
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• 2013

Traditional propellants release toxic gases during combustion that are harmful to the environment. This study describes a novel synthetic process of two high nitrogen containing tetrazines, TATTz and BTATz, which can be adapted as solid fuels for a solution to environmental concerns. The compounds were characterized by NMR, IR spectroscopy, and differential scanning calorimetry(DSC). Detonation properties were calculated with the EXPLO5 program based on calculated heats of formation and measured densities.

• Proceedings of the Korean Society of Propulsion Engineers Conference
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• 2017.05a
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• pp.766-774
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• 2017

Software has been developed for simulating particle dispersion in a circular pipe with sudden-expansion, which models the fuel feeding system of a combustor that uses metal powder like aluminum as fuel. The Lagrangian based discrete tracer point method was employed for a plug flow of particles that satisfies local turbulent velocity fluctuations. A radial velocity component was created to improve the flow turning outwards in the recirculation zone. The particle distribution patterns from both with and without the component were directly compared with the experiments near the reattachment.