• Title/Summary/Keyword: 열 복사

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Radiation Damage by the Pool Fire of LNG Storage Tank (LNG 저장 탱크의 Pool Fire에 의한 복사열 피해)

  • Sohn Jung-Hwan;Hahn Yoon-Bong
    • Journal of the Korean Institute of Gas
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    • v.2 no.1
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    • pp.14-22
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    • 1998
  • In this work, in order to quantitatively predict the radiation flux and propose an idea about how to reduce the radiation damage, the radiation flux caused by pool fire of an LNG storage tank has been calculated using the RISC (Risk and Industrial Safety Consultant) proposed model under various conditions. Model predictions showed that the most important parameter affecting the radiation flux by the LNG pool fire is the wind speed. The extent of radiation damage to a target from fire flame was more significant with variation of wind speed at a low wind speed than with that at a high wind speed. It was found that the radiation damage by the former is substantially reduced with planting windbreak system around the plant. Since the windbreak is most economical than any other method, it is strongly suggested to plant a tree belt in the factory surroundings, especially near by the area of gas storage facilities, linking with water cooling and fire protection systems.

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Studies of Parallelism and Performance Enhancements of Computing View Factor for Satellite Thermal Analysis (인공위성 열해석을 위한 복사형상계수 계산기법의 병렬화 및 성능향상 기법 연구)

  • Kim, Min-Ki
    • Journal of the Korean Society for Aeronautical & Space Sciences
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    • v.43 no.12
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    • pp.1079-1088
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    • 2015
  • Parallelism and performance enhancement of calculating view factors in KSDS developed by KARI is introduced in this paper. View factor is an essential parameters of radiation thermal analysis for a spacecraft, and the amount of computation of them is not negligible. Especially, independent integration of view factors at each position of the orbit because the relative displace between solar panel and main body of a satellite varies with the position on the orbit. This paper introduces a range of parallelism of computing view factor and their performance, detection of obstructions by spatial search algorithm based on KD-Tree, and the reduction of the calculation of view factors of a satellite with relative motion between solar panel and main body, called updating fractional view factor matrix, for satellite thermal analysis.

Numerical study on thermophoretic deposition of highly absorbing emitting particles suspended in a non-isothermal two-phase flow system (비등온 이상유동 시스템에 부유된 고흡수, 방사하는 입자의 열환산적 부착현상에 대한 수치적 연구)

  • Yoa, S. J.
    • Journal of the korean Society of Automotive Engineers
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    • v.11 no.5
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    • pp.90-100
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    • 1989
  • 본 논문은 이상유동 시스템에 부유도니 슈트, 미분탄과 같은 고 흡수, 방사하는 입자에 의한 열 확산 현상에 대한 복사효과를 수치적으로 검토하였다. 가스, 입자유동의 지배방정식들은 오일러 관점의 two-fluid model 의 근간에서 수행되었으며, 에너지 방정식의 비선형 복사생성항은 P-1 근사방법에 의해 계산되었다. 복사효과가 증가될 때에 열확산적 입자의 벽면에 대한 부착율은 상당히 낮아짐을 보였으며 열확산 현상의 스토크스 수에 따른 효과도 고려되었다.

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A Combustion Characteristic Analysis of Quercus Variabilis and Pinus Densiflora Fallen Leaves Using Radiation Heat Flux (복사열을 이용한 소나무와 굴참나무 낙엽의 연소특성 분석)

  • Park, Hyung-Ju;Kim, Eung-Sik;Kim, Jang-Hwan;Kim, Dong-Hyun
    • Fire Science and Engineering
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    • v.21 no.3
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    • pp.41-46
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    • 2007
  • The combustion characteristics of surface forest fire fuels was analysed using variable external irradiation level. The characteristics such as ignition time, ignition temperature, critical heat flux and mass loss rate were measured. Fuel samples were exposed to incident heat fluxes from 8 to $50\;kW/m^2$. For the measurement of various combustion characteristics, the size of specimen holder was $100\;mm{\times}100\;mm{\times}12\;mm$ and the fuel samples grinded by electric mill were the fallen leaves of Quercus variabilis and Pinus densiflora. As results, the occurrence of ignition is possible to the heat flux more than $9\;kW/m^2$. The fuel of Pinus densiflora keeps its high temperature longer than that of Quercus variabilis during the combustion process. The results of measurement shows that the maximun and average mass loss rate of Quercus variabilis larger than that of Pinus densiflora.

A Development of Thermal Radiation Plume Modelling for Heat Transfer to KSLV-II Engine Base (한국형 발사체 기저부 열전달 해석을 위한 플룸 복사 모델링 개념 개발)

  • Kim, Seong-Lyong;Ko, Ju-Yong;Kim, In-Sun
    • Proceedings of the Korean Society of Propulsion Engineers Conference
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    • 2012.05a
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    • pp.507-514
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    • 2012
  • In the present research, NASA LRB plume radiation models are reconstructed with Thermal Desktop software, where the radiation to vehicle base environment can be calculated. The calculation shows the similar radiation heat compared to NASA prediction. Based on LRB plume radiation model, a KSLV-II thermal radiation model is proposed.

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Development of Radiation Heat Shield of Monopropellant Thruster for Spacecraft (우주비행체 단일추진제 추력기의 복사 열차폐막 개발)

  • 이균호;유명종;최준민;김수겸
    • Journal of the Korean Society for Aeronautical & Space Sciences
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    • v.34 no.10
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    • pp.92-98
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    • 2006
  • An 1 lbf of NASA standard monopropellant thruster, MRE-1, is used for KOMPSAT (Korea Multi-Purpose Satellite) which is launched in 2006 and provides reliable and cost-effective means for attitude and maneuvering control system. The monopropellant thruster obtains required thrust by thermal decomposition process of propellant through catalyst bed. During firing, the decomposition plays a role of a heat source that may occur an excessive radiation heat transfer to peripheral structures and electronics in relatively low temperature condition.Therefore, the radiation heat shield is needed to prevent the critical radiative heat exchange between thruster and satellite during firing. This paper summarizes an overall development process of radiation heat shield from the design engineering up to the manufacturing.

A Study on Thermal Characteristics of Stratospheric Airship Considering Radiation Heat Transfer (복사 열전달에 의한 성층권 무인 비행선의 열 특성 연구)

  • Kim Seung-Min;Lee Sang-Myeong;Roh Tae-Seong;Choi Dong-Hwan
    • Proceedings of the Korean Society of Propulsion Engineers Conference
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    • 2005.11a
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    • pp.285-288
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    • 2005
  • A Stratospheric airship should stay long to achieve its original mission. Meanwhile, to obtain what the solar radiation and heat transfer have an effect on Stratospheric condition, heat analysis has been done. For this work, Stratospheric heat condition's been examined and for the numerical analysis, by using Gridgen, grids of airship have been generated. And by using STAR-CD, the study about heat characteristic of airship model was carried out. Especially, with changing the position of the Sun, the temperature change of the airship body was focused on. With this background, the possibility of realizing the simulation of the effects solar radiation have on the Stratospheric airship.

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An Experimental Study on the Radiant Heat of the Firedoors in Fire (화재시 방화문의 복사열에 관한 실험적 연구)

  • Jeon, Jun-Pyo;Jeon, Soo-Min;Cho, Nam-Wook;In, Ki-Ho;Rie, Dong-Ho
    • Fire Science and Engineering
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    • v.25 no.3
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    • pp.8-13
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    • 2011
  • The fire compartments which are composed of fire walls and fire doors for buildings are compulsorily required to minimize the fire damage in Korea. The performance standards of fire doors for compartments are regulated by the notification of the ministry of land, transport and maritime affairs and are mainly about the Integrity of the doors not insulation. In this study, we measured the radiant heat of six different kinds of fire doors in fire and analyzed the results and presented the reasons of the need to consider adding the radiant heat standard for fire doors to the notification.

Investigation of the Radiative Heating from Aircraft Plume with Particles (입자에 의한 항공기 플룸의 열복사 가열에 관한 연구)

  • Go, Gun-Yung;Yi, Kyung-Joo;Lee, Sung-Nam;Kim, Won-Cheol;Baek, Seung-Wook;Kim, Man-Young
    • Journal of the Korean Society for Aeronautical & Space Sciences
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    • v.40 no.9
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    • pp.737-744
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    • 2012
  • The finite volume method for radiation is applied for the analysis of radiative base heating by SE and PE of the aircraft exhaust plume. The exhaust plume is considered as an absorbing, emitting, and scattering medium, while the base plane is assumed to be cold and black. The radiative properties of non-gray gases are obtained through the WSGGM, and the particle is modelled as spheres. The present method is validated by comparing the results with those of the backward Monte-Carlo method and then the radiative base heating characteristics are analyzed by changing such various parameters as particle concentration, temperature, and scattering phase function. The results show that the radiative heat flux coming into the base plane decreases with altitude and distance, but it increases as the particle temperature increases. The forward scattering of particles increases PE while it decreases SE.