• Journal of computational fluids engineering
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• v.12 no.3
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• pp.62-68
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• 2007

A conceptual thermal design is performed for the optical payload system of a geostationary satellite. The optical payload considered in this paper is GOCI(Geostationary Ocean Color Imager) of COMS of Korea. The radiative thermal control system is employed in order to expect a small thermal gradient in the telescope structure of GOCl. Two design margins are applied to the dedicated radiator dimensioning, and three kinds of configuration to the heater power sizing. A Monte-Carlo ray tracing method and a network analysis method are utilized to calculate radiative couplings and thermal responses respectively. At the level of conceptual design, sizing thresholds are presented for the radiator and heater on the purpose of determining the mass and power budget of the spacecraft.

• 한국전산유체공학회:학술대회논문집
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• 2005.04a
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• pp.91-95
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• 2005

A heat dissipation modeling method of EEE parts is developed for thermal design and analysis of an satellite electronic equipment. The power consumption measurement value of each functional breadboard is used for the heat dissipation modeling method. For the purpose of conduction heat transfer modeling of EEE parts, surface heat model using very thin ignorable thermal plates is developed instead of conventional lumped capacity nodes. The thermal plates are projected to the printed circuit board and can be modeled and modified easily by numerically preprocessing programs according to design changes. These modeling methods are applied to the thermal design and analysis of CTU and verified by thermal cycling and vacuum tests.

• Journal of computational fluids engineering
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• v.13 no.2
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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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• 2007.10a
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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.

• Proceedings of the Computational Structural Engineering Institute Conference
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• 2011.04a
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• pp.579-582
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• 2011

본 논문에서는 9 % Ni강 LNG 저장탱크 조사를 통해서 유한요소해석을 수행하여 구조건전성을 평가하였으며 실용에서 활용할 수 있는 자료를 제시하였다. 과거의 LNG 저장탱크의 설계는 2차원 선에서만 유한요소해석이 수행되었으나 보다 진보된 하드웨어와 소프트웨어의 발전으로 3차원 유한요소해석이 가능케 되었다. 본 연구에서는 9 % Ni 강 LNG 저장탱크 내조의 정적 구조 해석이 상용 유한 요소 해석 프로그램인 ABAQUS를 통해 수행되었다. LNG 저장 탱크 내조 시공 시 용접부 형상을 참고하여 용접부 모델을 고려한 해석을 각각 수행하였다. 용접부의 탄성계수의 변화를 통하여 최대응력과 최대변위를 계산하였다. 실제 LNG tank의 운용 시 발생하는 하중은 자중과, 수두 압과, 온도차에 의한 열응력이며 이들이 복합적으로 작용하였을 시, 용접선을 고려하지 않은 모델에 대해서는 최대응력이 207 MPa이며, 동일 조건에서 용접선을 포함한 모델에 대해 해석을 수행한 결과로서 최대응력이 그보다 약 100 MPa 정도 상승한 결과가 나타났다. 하중조건에서 온도차에 의한 열응력을 고려함과 고려하지 않음을 비교함으로서 실제 열응력에 대해서는 내조에 큰 영향을 미치지 않음을 확인하였다.

• Proceedings of the Korean Vacuum Society Conference
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• 2014.02a
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• pp.140.2-140.2
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• 2014

인공위성은 우주공간의 고진공 상태와 태양 복사열에 의한 고온 및 극저온이 반복되는 가혹한 환경으로 인해 주요 부품의 기능장애가 초래되므로 발사전 지상에서 열진공 시험장비를 이용한 열진공시험을 수행한다. 위성체의 열진공 시험에 사용되는 열교환기인 베이스플레이트(Baseplate)는 우주 열환경을 모사하기 위하여 직접 방열판 표면에 고온 및 저온의 유체를 공급하여 시험 요구에 따른 필요한 열을 공급하게 된다. 일반적으로 우수한 성능의 위성체 부품의 검증을 위해서 지상의 열환경 시험은 접촉식 히터 및 열교환기를 사용하게 되는데, 이때 적절한 히터 및 블로워 파워를 선정하고 챔버 슈라우드와 열교환에 있어 간섭이 없도록 장비를 운용해야 한다. 본 연구에서는 상용프로그램을 이용하여 열진공 시험용 베이스플레이트에 대하여 전산해석을 수행하였으며, 이를 통해 베이스플레이트 내의 작동 유체의 입구 압력에 의한 열진공 시험용 열교환기의 성능 특성을 관찰하였다.

• Computational Structural Engineering
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• v.7 no.4
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• pp.151-158
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• 1994

The free vibrations of thermally buckled, simply supported, symmetrically laminated, rectangular, and quasi-isotropic plates are investigated. The nonlinear postbuckling analysis is performed by the finite element method based on the first order shear deformable plate theory with the use of von Karman type nonlinear strains and the Duhamel-Newman type constitutive law. The postbuckling solutions are used to obtain free vibration responses of buckled plates. Several numerical examples for quasi-isotropic laminated plates are considered. The effects of width-to-thickness ratios and aspect ratios on the free vibration characteristics of buckled plates are investigated.

• 한국전산유체공학회:학술대회논문집
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• 2011.05a
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• pp.173-178
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• 2011

Nowadays, SELENE-2 is under development for the moon explorer rover in Japan. AXS(Active X-ray Spectrometer) sensor development among the candidated payloads will be on going by the world-wide co-operation. The thermal design, analysis and test will be specially performed by Korean institutes. CFD techniques are used for the conceptual design and analysis. Thin-shell plate meshes being applied by Monte-Carlo Ray Tracing Method are generated for the thermal radiation analysis. Lumped capacity model is employed for the thermal conduction simulation of the AXS payload itself. Various shapes of the payload configuration with thermal boundary conditions are proposed and selected on the purpose of the analysis of the initial design. The results of the analysis are supposed to be used as the baseline for the further detailed design of the AXS payload in the future.

• Journal of the KSME
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• v.34 no.8
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• pp.632-642
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• 1994

이 글의 앞부분에서는 소각로 관련 선진기술 중에서 소각 연소실부분에 대한 내용을 검토하고, 저공해화를 위한 연소실을 설계할 때 고려해야 할 인자들을 도출한다. 이러한 설계인자들에 대한 정량적인 평가는 설계개념 확인 및 설계인자의 검토를 위한 연소, 유동, 열전달 등 실험실 규모의 실험과 열유동의 전산해석 기법을 활용하여 설계변수의 최적화를 통해 이루어진다. 이 글에서는 컴퓨터. 프로그램을 사용하는 전산유동해석, 축소 모형장치를 사용하는 실험 등 열유동 해석법과 고형 폐기물의 연소특성을 분석하는 실험적.이론적 접근법을 소개한다.

• Computational Structural Engineering
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• v.8 no.2
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• pp.141-145
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• 1995

This paper deals with a time-domain boundary element technique suitable for the analysis of linear viscoelastic materials in the presence of transient temperature field. Thermorheologically simple behavior has been assumed. Following an exposition of the boundary element formulation, the numerical results of example problem have been presented.