• 한국전산유체공학회지
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• 제11권3호
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• pp.8-13
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• 2006

The north panel of a geostationary satellite is used as one of the main radiators, on which communication equipment or bus equipment are installed. The thermal control of panel is designed by using embedded heat pipes and surface heat pipes (or external heat pipes) to spread out heat dissipated from equipment all over the radiator evenly and finally to reject the heat to the space through the radiator efficiently. This panel is also divided by several areas based on the operating temperature and dissipation of equipment in order to increase heat rejection capability of radiator. The thermal analysis is carried out for the hot case, Winter Solsitce EOL (End Of Life), in order to validate thermal design of the panel utilized 6 surface heat pipes and 8 embedded heat pipes. The sensitivity studies for the heat pipe failure case and no heat pipe case are performed and compared to its normal state. The heat transport capability of heat pipe is also obtained from these calculations.

• 한국기계가공학회지
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• 제15권5호
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• pp.25-30
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• 2016

This study investigates the heat transfer due to a change in the shape of a radiator panel inside a computer. As with models of radiator panels, models have the same surface areas. As the gap between heat transfer surfaces in model 1 becomes wider than those in model 2, the heat transfer at model 1 becomes smoother than that of model 2. By comparing the cooling processes between models 1 and 2 with respect to natural convection, a maximum temperature of $47.432^{\circ}C$ at model 1 becomes lower than that of model 2, at $49.821^{\circ}C$. Within the radiator panel, model 1 has been shown to be more effective than model 2. Accordingly, these results can be effectively applied to the shape design of radiator panels to imbue them with smoother and faster heat transfer through the finite element method.

• 한국전산유체공학회:학술대회논문집
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• 한국전산유체공학회 2010년 춘계학술대회논문집
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• pp.416-421
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• 2010

The north and south panel of a geostationary satellite are used for radiator panels to reject internal heat dissipation of electronics units and utilize several heat pipe networks to control the temperatures of units and the satellite within proper ranges. The design of these panels is very important and essential at the conceptual design and preliminary design stage so several thousands of nodes of more are utilized in order to perform thermal analysis of panel. Generating a large number of nodes(meshes) of the panel takes time and is tedious work because the mesh can be easily changed and updated by locations of units and heat pipes. Also the detailed panel model can not be integrated into spacecraft thermal model due to its node size and limitation of commercial satellite thermal analysis program. Thus development of a program was required in order to generate detailed panel model, to perform thermal analysis and to make a reduced panel model for the integration to the satellite thermal model. This paper describes the development and the verification of panel thermal analysis program with ist main modules and its main functions.

• 한국전산유체공학회지
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• 제15권3호
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• pp.66-72
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• 2010

The north and south panel of a geostationary satellite are used for radiator panels to reject internal heat and utilize several heat pipe networks to control the temperatures of units and the main structures of satellite within proper ranges. The design of these panels is very important and essential at the conceptual design and preliminary satellite design stage, so several thousands of nodes or more are utilized in order to perform detailed thermal analysis of panel. Generating a large number of panel nodes takes time and is tedious work because the nodes can be easily changed and updated by locations of units and heat pipes. Also the detailed panel model can not be integrated into spacecraft thermal model due to its node size and limitation of commercial satellite thermal analysis program. Thus development of a program was required to generate a detailed panel model, to perform thermal analysis and to make a reduced panel model for the integration to the satellite thermal model. This paper describes the development and the verification of the panel thermal analysis program with its main modules and functions.

• 항공우주기술
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• 제10권2호
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• pp.114-120
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• 2011

인공위성의 효율적인 열제어를 위해 알루미늄으로 만들어진 하니콤 패널과 OSR로 구성된 방열판을 사용한다. 또한 추가적으로 발열량이 많은 부품의 경우, 알루미늄으로 만들어진 더블러와 히트파이프 등을 이용하여 열제어를 수행한다. 최근 위성 전장 부품의 발열량의 증가로 정해진 위성의 크기, 발사 중량 및 비용으로 더 많은 열을 외부로 효율적으로 방출할 수 있는 방열 능력향상에 대한 필요성으로 새로운 열제어 물질에 대한 연구가 진행 중이다. 특히, 탄소 복합재는 일반적으로 열전도가 매우 높고, 가볍고, 기계적 강성에 좋은 특성이 있어 차세대 열제어를 위한 물질로 많은 연구가 진행되고 있다. 본 논문에서는 차세대 탄소 복합재인, APG(Annealed Pyrolytic Graphite)와 탄소-탄소 복합재(carbon-carbon composites)를 이용하여 통신패널의 열제어를 수행하는 경우와 기존의 열제어 방식과의 차이를 수치적으로 비교하였다.

• 한국주거학회논문집
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• 제15권4호
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• pp.55-63
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• 2004

The aims of this research are to find the difference of space origination between Korean-Chinese and Chinese multi-family housing unit plan and to find the main reason to make this difference. To do this research, twenty three different kinds of floor plans were surveyed and examined. The results are as follows; 1. The Chinese-Korean floor plan and Chinese floor plan in Ondol heating system are totally different, although in radiator and floor panel heating system are similar. The inner space origination between two races are different. That is to say, Chinese-Korean likes open space origination and Chinese likes closed space origination. 2. The main reasons to make differences seem to be living style, heating system, constructional method and the trade with South Korea. In the future time, the usage of floor panel heating system will be increased and various kinds of floor plan should be introduced.

• 한국항공우주학회지
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• 제39권5호
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• pp.474-480
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• 2011

지구의 저궤도에서 운용되는 영상센서는 극저온 환경에서 태양 복사 뿐 아니라 지구의 적외선 및 알베도(Albedo)의 영향을 받는다. 극한 환경에 노출되는 영상센서는 작동/비작 동시 허용 온도를 벗어나지 않도록 열설계가 필요하며, 정상상태 에너지 평형식을 통해 필요한 방열판 면적 및 히터 예비 설계 값을 설정한다. 일반적으로 위성체 패널에 주기를 갖는 발열장비가 장착되어, 패널의 일부를 방열판 면적으로 설계한다. 본 논문에서는 위성체와 분리하여 설계하는 영상센서의 열제어를 위하여, 내부에서 항상 발열하는 장비의 열을 히트파이프를 이용하여 패널에 장착된 방열판으로 효과적으로 전달하도록 설계하였다. 예비 설계값을 기준으로 수치해석에 기반을 두는 SINDA를 이용하여 궤도 열해석을 실시하여, 방열 면적 및 히터 설계는 쉽고 빠르게 계산되어졌다. 또한, 방열 성능을 유지하면서 질량을 줄이도록 방열판을 립형상(Rib-type)으로 설계하였으며, 궤도 열해석 결과, 영상센서의 열적 요구사항을 만족함을 검증하였다.

• 공업화학
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• 제10권1호
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• pp.118-123
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• 1999

본 연구에서는 자동차의 instrument panel로부터 분리, 회수된 재생 PC/ABS계에 흡착되어 있는 PU foam이 가공온도조건에 따라 PC/ABS계의 모폴로지 및 기계적 물성에 미치는 영향을 조사함으로써 상용화제 첨가없이 PU의 열적성질을 이용한 모폴로지 제어에 의해 큰 폭의 물성저하를 막아 재생 PC/ABS를 자동차 라디에디터 그릴 소재로 적용하고자 하였다. 가공 온도조건에 따른 PU의 열적특성에 초점을 맞추어 고온 ($260^{\circ}C$) 및 저온 ($220^{\circ}C$)에서 재생PC/ABS와 신재 PC/ABS를 다양한 조성으로 용융 블렌드하여 고차구조 및 기계적 물성을 조사하였다. 신재 함량이 증가함에 따라 물성이 향상되었고, 고온 및 저온용융 블렌드물의 물성에는 큰 차이가 없었으나 충격강도는 고온용융 블렌드물이 월등히 우수하였다. 이것은 PU foam이 고온에서 높은 전단응력을 받아 보다 미세하고 균일하게 분산되었기 때문이라는 것을 발견했다.

• 한국전산유체공학회지
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• 제13권2호
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• pp.48-54
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• 2008

COMS (Communication, Ocean and Meteorological Satellite) is a geostationary satellite and has been developing by KARI for communication, ocean and meteorological observations. It will be launched by ARIANE 5. Ka-band components are installed on South panel, where single solar array wing is mounted. Radiators, embedded heat pipes, external heat pipe, insulation blankets and heaters are utilized for the thermal control of the satellite. The Ka-band payload section is divided several areas based on unit operating temperature in order to optimize radiator area and maximize heat rejection capability. Other equipment for sensors and bus are installed on North panel. The ocean and meteorological sensors are installed on optical benches on the top floor to decouple thermally from the satellite. During the transfer orbit operation, satellite will be under severe thermal environments due to low dissipation of components, satellite attitudes and LAE(Liquid Apogee Engine) firing. This paper presents temperature and heater power prediction and validation of thermal control design during transfer orbit operation.

• 한국전산유체공학회:학술대회논문집
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• 한국전산유체공학회 2007년도 추계 학술대회논문집
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• pp.227-231
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• 2007

COMS (Communication, Ocean and Meteorological Satellite) is a geostationary satellite and has been developing by KARI for communication and ocean and meteorological observations. It will be launched by ARIANE 5. Ka-band components are installed on South panel, where single solar array wing is mounted. Radiators, embedded heat pipes, external heat pipe, insulation blankets and heaters are utilized for the thermal control of the satellite. The Ka-band payload section is divided several areas based on unit operating temperature in order to optimize radiator area and maximize heat rejection capability. Other equipment for sensors and bus are installed on North panel. The ocean and meteorological sensors are installed on optical benches on the top floor to decouple thermally from the satellite. During the transfer orbit operation, satellite will be under severe thermal environments due to low dissipation of components, satellite attitudes and LAE(Liquid Apogee Engine) firing. This paper presents temperature and heater power prediction and validation of thermal control design during transfer orbit operation.