• Transactions of the Korean Society of Mechanical Engineers
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• v.8 no.3
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• pp.274-287
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• 1984

밀폐용기 내의 자연대류에 의한 흐름현상에 고유하며 아직까지 해결되지 않고 있는 중요한 문제 는 그 내부흐름의 형태를 주어진 물리적인 조건으로부터 미리 예측할 수 없다는 것이다. 이는 이 문제의 해석적인 해결에 가장 큰 난점이 되고 있다. 본 논문에서는 multiple scales method를 이 용한 해석적인 모델을 개발하여 종횡비가 낮은 직각형 밀폐용기 내에서 운동력이 코어에 존재하 는 경우 그 내부 흐름형태를 scaling analysis를 통해 정성적으로 예측, 기존의 결과와 비교 검토 하였다.

• Transactions of the Korean Society of Mechanical Engineers
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• v.8 no.4
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• pp.375-384
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• 1984

본 연구에서는 종횡비가 낮은 직사각형 밀폐용기 내에 Rayleigh수가 충분히 커서 흐름의 운동력이 용기 양단에 존재하는 경우에 PartⅠ에서 개발된 해석적인 모델 을 근거한 scaling analysis를 통해 그 내부 흐름 형태를 정성적으로 예측, 기존의 결 과와 비교, 검토하였다. 해석결과, Prandtl수에 따라 여러가지 내부 흐름 형태가 존 재할 수 있음이 밝혀졌으며 용기 내 뚜렷한 경계층 흐름이 존재하기 위한 필요조건도 아울러 얻어졌다.

• Transactions of the Korean Society of Mechanical Engineers
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• v.13 no.6
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• pp.1330-1338
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• 1989

본 연구에서는 직각밀폐용기의 수평경계면이 단열인 경우뿐만 아니라 등온 조건을 갖는 경우에 대해 실험적으로 연구하여 경계조건의 변화가 직각밀폐용기내 흐름 및 열전달에 미치는 영향, 특히 등온조건을 갖는 경우 수직 온도차에 따르는 안정온도 구배효과로 예상되는 흐름의 억제, 지연효과를 작종 물리적 변수들의 영향과 함께 세밀히 조사하였다.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.39 no.12
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• pp.1166-1173
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• 2011

Electro-Mechanical Ignition Safety Device(EMISD) for solid rocket motor is designed and manufactured. The EMISD utilizes a true rotary solenoid for arming mechanism and an electric squib(initiator) for generating ignition energy. In order to prove the ignition capability of the EMISD, 10-cc Closed Bomb Test(CBT) is performed, which measures the pressure built by high temperature and high pressure gas generated by operating EMISD. The pressure built in the free volume of 10-cc closed bomb and the opening time of the ignition gas outlet are calculated using one dimensional gas dynamic model which is composed of the ideal gas equation and mass-energy conservation equation. Comparing the test result with model prediction, it is realized that the pressure built in the free volume of closed bomb due to the firing of EMISD, has the efficiency ratio of about 34%.

• Proceedings of the Korean Society of Propulsion Engineers Conference
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• 2011.11a
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• pp.332-335
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• 2011

Electro-Mechanical Ignition Safety Device(EMISD) for solid rocket motor is designed and manufactured. The EMISD utilizes a true rotary solenoid for arming mechanism and an electric squib(initiator) for generating ignition energy. In order to prove the ignition capability of the EMISD, 10-cc Closed Bomb Test(CBT) is performed, which measures the pressure built by high temperature and high pressure gas generated by operating EMISD.

• Explosives and Blasting
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• v.30 no.2
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• pp.43-51
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• 2012

The Demolition blasting has been applied for buildings and structures so far. In this study, however, a confined vessel blasting filled with water has been focused. A small amount of explosives were placed in a sealed vessel with water, perfect elastic body, supposed as a relay agent in it, and the blasting aspect was observed. Blasting pressure was standardized by Abel's equation of state. In result, if there was a relay agent in it, the pressure vessel was torn apart with smaller power than its tensile strength. If there was not, it needed 7.1~8.5 times as much power as the previous one, and the blasting pressure had not also affected the demolition and it had gone or vanished until it reached a certain point, In terms of pressure vessel made by steel, the elastic-plastic failure was took a place, and the first yield point happened along the welded area as a form of heating plastic failure we thought.

• Journal of the korean Society of Automotive Engineers
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• v.10 no.6
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• pp.61-71
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• 1988

본 논문에서는 Laser Rayleigh Pyrometer에 의한 광학계의 개조와 측정기술을 발전시켜 지금까지의 측정이 불가능한 밀폐용기내에서 분출화염의 온도측정을 시도하여 분출화염에 의한 착화나 소염의 연구에 중요한 자료를 얻고자 하는데 있다. 밀폐용기내에서의 온도측정은 대기개방형에서와 같이 Laser의 에너지를 증대시키기 위해 이용한는 다중반사 Mirror가 사용될 수 없을 뿐만 아니라 약한 Rayleigh산란빛에 의하여 입사창이란 Laser Trap으로 발생하는 강한 배경광 및 분출화염 뿐만 아니고 착화된 화염에서 대량의 화학발광은 피할 수 없다. 본 논문은 이와 같은 영향을 제거하는데 노력하여 밀폐용기내의 연소장에서 온도를 측정하였으며 또 측정가능성을 시사하였다.

• Proceedings of the Materials Research Society of Korea Conference
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• 2007.11a
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• pp.31.2-31.2
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• 2007

• Transactions of the Korean Society of Mechanical Engineers
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• v.10 no.2
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• pp.247-256
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• 1986

An experimental investigation was conducted to study natural convection due to temperature and concentration differences between the two opposite end walls of a rectangular enclosure of aspect ratio 0.2. Flow motion in the enclosure appears as a uni-cell flow pattern for the relatively lower concentration and higher temperature differences and vice versa, while it appears as a multicell flow pattern for the comparable temperature and concentration differences. In the multi-cell flow regime, when the cellular flow motiion is very slow, vertical temperature differences within the cells are negligible while the vertical concentration differences are large. In addition, both the temperature and concentration differences are negligible across the interface between the slowly moving cells. For the fast moving cellular flow motion, on thel contrary, vertical temperature differences within the cells are large while the vertical concentration differences are negligible. In this case, temperature differences are negligible and the concentration differences are large across the interface between the fase moving cells.

• KAPE Magazine
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• s.207
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• pp.8-9
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• 2013