• Title/Summary/Keyword: The radiation heat

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A Study on the Thermal and Flow Characteristics of Wind and Radiant Heat Shield for Offshore by using Mesh Screen (메쉬 스크린을 적용한 해양구조물용 방풍 및 복사열 차단막 열유동특성에 관한 연구)

  • Yi, Chung-Seob;Chin, Do-Hun
    • Journal of the Korean Society of Manufacturing Process Engineers
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    • v.11 no.3
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    • pp.166-173
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    • 2012
  • This study is about comparison of thermal and flow characteristics on the wind & radiant heat shield with STS mesh type screen for offshore. Numerical analysis was conducted to find transmission coefficient in the mesh and then analyse the flow characteristics about wind & radiant heat shield. The experiment method of solar radiation has been used as thermal radiation source to get the performance of radiant heat shield measurement. The sensor radiation device has been used to measure the reduction of solar radiation with various size of cells and at a distance of 0.5m and 1m from the cold face of the wind & radiant heat shield.

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.

Study on Performance of Radiant Heat Shields for Offshore Installations (해양플랜트 복사열 차폐막의 차폐성능에 관한 연구)

  • Kim, Bong Ju
    • Journal of Ocean Engineering and Technology
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    • v.33 no.4
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    • pp.330-339
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    • 2019
  • Radiant heat shields are normally installed on offshore oil and gas platforms to protect personnel, equipment, and structures from the thermal radiation emitted by a flare system. A heat shield should be individually designed to reduce the thermal radiation to the target level, and then manufactured and installed after the performance verification. However, in general, a heat shield is designed and manufactured by trial and error based on the performance test. For this reason, it is difficult to develop and design radiant heat shields in the Korean shipbuilding and marine equipment industry because of the lack of performance test data and limited experience. In the present study, the results of experiments conducted to verify the performances of radiant heat shields were analyzed, and the thermal radiation characteristics and performance characteristics of the radiant heat shields were investigated. The insights and conclusions developed in the present study will be useful in terms of the design and development of radiant heat shield, as well as in their performance verification tests.

A Study on Heat Simulation for Heat Radiation in 150W LED (150W LED등기구 방열을 위한 열 해석에 관한 연구)

  • So, Byung Moon
    • Journal of the Semiconductor & Display Technology
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    • v.15 no.4
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    • pp.79-85
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    • 2016
  • For long life time and high efficiency, not necessary in improvement of LED chip structure, but also improve heat radiation for decrease heat in LED chip. In this study, efficiency decline factor has been investigated in LED lamp as study heat characteristic, luminance flux and heat resistance. When LED lamp temperature was increased, about 7% loss of luminance flux. In consequence of temperature analysis, width of fin was the most important factor of heat radiation. As a result, secure the enough heat path is very important factor of LED lamp design.

An Experimental Study on the Effects of a Radiation Shield on the Thermal Load of a Cryochamber (복사 차폐막이 극저온 용기의 부하에 미치는 영향에 관한 실험적 연극)

  • Kim, Young-Min;Park, Seong-Je;Kang, Byung-Ha
    • Proceedings of the SAREK Conference
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    • 2005.11a
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    • pp.365-370
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    • 2005
  • Infrared (lR) detectors are widely used for such applications as thermoelstic stress analysis, medical diagnostics and temperature measurement. Infrared detectors commonly need to be refrigerated below 80 K, and thus a cooling system should be equipped together with the detector system. The cooling load, which should be removed by the cooling system to maintain the nominal operating temperature of the detector, critically depends on the insulation efficiency of the cryochamber housing the detector. Cryochamber considers the conduction heat transfer through a cold finger, the gases conduction and radiation heat transfer. The thermal loads of an infrared detector Cryochamber with radiation shield are investigated experimentally in present study. Since the effect of radiation heat transfer on thermal loads is significant, radiation shields is installed in the cold finger part to protect heat input through radiation. It is found that the thermal load can be substantially reduced by increasing the number of radiation shield.

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A Study on Radiation Heat Transfer of Wafer Transfer Module Using Computational Flow Visualization (전산유동가시화를 활용한 웨이퍼 이송장치의 복사열전달에 관한 연구)

  • Min Gi, Chu;Ji Hong, Chung;Dong Kee, Sohn;Han Seo, Ko
    • Journal of the Korean Society of Visualization
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    • v.20 no.3
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    • pp.58-66
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    • 2022
  • The high heat emitted from the process module and heat jacket may cause errors in semiconductor process equipment. Barriers were designed to reduce the temperature of surface on transfer module. A designed barrier was compared and analyzed by numerical analysis using ANSYS Fluent. The average temperature of barrier and effect of radiation heat transfer were also compared through absorbed radiative heat flux of the barrier. The adoption of the barrier had an effect on the radiative heat transfer reduction of the transfer module rod. The effect of the angles of barrier from 50° to 90° on the heat transfer was investigated using the absorbed radiative heat flux with the average temperature. The angle of barrier of 50° reduced the temperature up to 9.6 %.

Numerical Investigations of Enhancement of a Convective Fin Efficiency by Convection-Radiation Gonjugate Heat Transfer (대류-복사 복합 열전달을 고려한 대류 핀효율의 향상에 관한 수치적 연구)

  • 이동렬;김호용;이재곤;박용국;김기대
    • Journal of Advanced Marine Engineering and Technology
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    • v.25 no.1
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    • pp.146-154
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    • 2001
  • In almost all real situations, there will be a radiant interchange between adjacent fins with the base surface as well as with the external environment. In the problem of this study, a rectangular fin is attached to a based. Our concern is whether the convective fin efficiency can be increased by the radiation heat exchanged between the fin and the base surface and how much. If the fin temperature toward the tip increased by the effect of radiation, the convective heat transfer increase due to the temperature difference between the ambient temperature and the surface temperature of the fin. If this true, the efficiency of the fin due to the radiation will increase. Attention is directed toward several parameters which have major roles on getting values of the fin efficiencies in several different values of parameters. Many different cases are, therefore, to be examined to have maximum fin efficiency by varying the values of each parameter.

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An Investigation of Radiation Heat Transfer on The Horizontal Fin of An External Fuel Tank by Flame of a Flying Flare (날아가는 섬광탄이 연료탱크 수평핀에 미치는 복사열전달 연구)

  • Jung, Daehan;Kang, Chihang;Kim, Sitae
    • Journal of the Korea Institute of Military Science and Technology
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    • v.17 no.2
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    • pp.197-203
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    • 2014
  • In this paper, the effect of unsteady radiation on the horizontal fin of an external fuel tank by flame of a flying flare was analysed to see the temperature increase of the fin and the thermal impact on the fin. Radiation between two surfaces was calculated using the concept of radiation resistance of surface and space including radiation, irradiation and shape factor for two flying trajectories of a flare, maximum temperature of 2200 K, emissivity of 0.95, flying velocity of 30 m/s, and thermal surface area of $0.01m^2$. The result shows that the temperature increase of the fin is 0.236 K, and the thermal effect on the fin is ignorable. And it was found that temperature is increased a little because small amount of heat energy can be radiated due to the short exposure time to the heat source.

Introduction of Japanese Ocean Flux data sets with Use of Remote sensing Observations (J-OFURO)

  • Kubota, Masahisa
    • Proceedings of the KSRS Conference
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    • 1999.11a
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    • pp.231-236
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    • 1999
  • Accurate ocean surface fluxes with high resolution are critical for understanding a mechanism of global climate. However, it is difficult to derive those fluxes by using ocean observation data because the number of ocean observation data is extremely small and the distribution is inhomogeneous. On the other hand. satellite data are characterized by the high density, the high resolution and the homogeneity. Therefore, it can be considered that we obtain accurate ocean surface by using satellite data. Recently we constructed ocean surface data sets mainly using satellite data. The data set is named by Japanese Ocean Flux data sets with Use of Remote sensing Observations (J-OFURO). Here, we introduce J-OFURO. The data set includes shortwave radiation, longwave radiation, latent heat flux, sensible heat flux, and momentum flux etc. Moreover, sea surface dynamic topography data are included in the data set. Radiation data sets covers western Pacific and eastern Indian Ocean because we use a Japanese geostationally satellite (GMS) to estimate radiation fluxes. On the other hand, turbulent heat fluxes are globally estimated. The constructed data sets are used and shows the effectiveness for many scientific studies.

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