• Proceedings of the Korean Society of Dyers and Finishers Conference
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• 2009.11a
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• pp.67-68
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• 2009

• Proceedings of the SAREK Conference
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• 2004.06a
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• pp.118-118
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• 2004

• Journal of Drive and Control
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• v.6 no.2
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• pp.17-25
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• 2009

• Journal of Drive and Control
• /
• v.9 no.4
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• pp.105-118
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• 2012

• Proceedings of the Korean Society of Rheology Conference
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• 2006.06a
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• pp.135-138
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• 2006

• Journal of the Speleological Society of Korea
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• v.34 no.35
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• pp.23-31
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• 1993

환선굴은 이른바 복합형이면서도 토출형의 석회동굴이다. 동굴내 지형의 기복이 다양하고 동굴 내부에 수많은 대소의 폭포와 여울이 걸려 있는 동굴유가 풍부한 동굴이며 동굴의 2차생성물은 이 동굴의 지표면을 이루고 있는 지층이 빈약하므로 2차생성물의 성장이 활발하지 못한 동굴이다. 동굴 천정의 지층 구조로 보아 제 Ⅰ지구에서는 비교적 이차생성물이 발달되고 있으나 그밖의 동굴 내부지역에서는 발달이 미약하다.(중략)

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2007.05a
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• pp.633-640
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• 2007

In this paper, 3-D reciprocating compressor is taken into flow-structure interaction analysis. The full cycle process consisted of cylinder expansion and compression has been modeled without considering flow leakage through cylinder wall. Fully-coupled FSI analysis of this compressor model was iteratively solved and gives sufficient result with the experimental test. The study is emphasized to thoroughly investigate discharge valve motion, opening and closing, in order to determine discharge valve region which is prone to have high effective stress. The cylinder pressure is successfully validated before conducting impact analyses between discharge valve and other susceptible supported structure. Velocity profile has been obtained in FSI analysis is used as initial condition to carry out further impact analyses. Stress result of discharge valve and valve spring gives preliminary estimation of higher stress area due to its impact phenomena.

• Proceedings of the Korean Society of Propulsion Engineers Conference
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• 2005.11a
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• pp.220-223
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• 2005

System design parameters of gas generator cycle liquid rocket engines were investigated and compared in the present study. Characteristic velocity of combustor, pressure drop of combustor injector, exit pressure of pump, pump efficiency and specific power of turbine were considered as a system design parameter. The result shows the characteristic velocity is in the range of 1700-1770 m/s, pressure drop of combustor injector, 4-10 bar, pump exit pressure ratio to combustion pressure, 120-230%, pump efficiency, 60-80%, specific power of turbine, $0.28-0.58MW{\cdot}s/kg$.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.13 no.4
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• pp.1503-1510
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• 2012

In this research, various cases of centrifugal impeller for HVAC system have been numerically analyzed by changing center angle of blades and length of outlet. Commercial CFD code, FLUENT has been used to calculate velocity, pressure, turbulence intensity, and temperature that can lead numerous results. Regardless of warming up, when the heater power level was increased, the temperature inside surrounding impeller also increased due to flowing outer air, but the temperature decreased because of flowing inner air. Consequently, the variation of central angle of blades and length of outlet led difference of velocity and flow rate which can reduce $CO_2$ in gas emission.

• Korean Journal of Air-Conditioning and Refrigeration Engineering
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• v.30 no.2
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• pp.51-57
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• 2018

Recently, global warming has been a serious issue on the worldwide, and the importance of energy conservation is increasing. In most buildings, energy consumption increases due to cooling, heating, and ventilation. Because of these issues, researches have been carried out to reduce building energy. However, in most conventional forced-air system, the guidelines for the Air Handling Unit (AHU) discharge air temperature are not fully established. The purpose of this study is to assess the impact of AHU discharge air temperature, which is one of the important control variables, on the overall energy consumption and thermal comfort characteristics by modeling conventional forced-air system using EnergyPlus. In addition, recommendations for energy reduction in conventional AHU is provided.