• Title/Summary/Keyword: Distribution of Thermal Factor

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Analysis of Thermal Comfort Factor′s Distribution in Convective Heating Space (대류난방공간에서 온열쾌적조건의 분포상태 분석에 관한 연구)

  • 공성훈
    • Journal of the Korean housing association
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    • v.6 no.1
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    • pp.31-37
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    • 1995
  • The purpose of this study is to analyse the distribution of thermal sensation response and thermal environment condition in convective heating space. The contents of this study are as follows: 1)the spatial distributions of thermal conditions are measured 2)the thermal sensation vote of residents is taken in order to investigate the relation between thermal condition and human thermal sensation in sedentary condition 3)to analyse the distribution of subject's thermal sensation vote and thermal environment condition by two methods-regression method and graph method.

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A Study of Thermal Radiation from The Alumina Particle Cloud in The Plume Using View Factor Method (형상 계수를 이용한 알루미나 입자구름의 열복사 예측 기법 연구)

  • Ko, Ju-Yong;Kim, In-Sun
    • Proceedings of the KSME Conference
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    • 2007.05b
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    • pp.2044-2049
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    • 2007
  • In order to predict the thermal radiation induced from alumina particle cloud in the plume of solid propellant motor, view factor method is applied to space shuttle SRB and the result is compared with that of monte carlo method. For this purpose, radiative characteristics, such as particle cloud temperature distribution, effective emissivity or emissive power of particle cloud are studied. In the case of effective emissivity, inverse wavelength method is applied and plume reduction characteristic length is used for emissive power distribution. As a result, thermal radiation using view factor method gives more conservative results than that using monte carlo method. So it can be used for preliminary design of thermal protection system.

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An Analysis of Indoor Thermal Environment by Macro Model (매크로 모델에 의한 실내온열환경 검토)

  • Jung, Jae-Hoon
    • Proceedings of the SAREK Conference
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    • 2008.11a
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    • pp.584-589
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    • 2008
  • It is known that slab thermal storage which uses concrete slab as thermal material is effective in the load leveling and using the nighttime electric power. The temperature distribution is not constant in plenum in thermal storage time by beams, ducts such as several factor. It is considered that this fact will effect on efficiency of thermal storage and indoor thermal environment. The purpose of this paper is to examine the thermal environment inside plenum. A macro model was made for the analysis of indoor thermal environment as the first step. The flow rate distribution and temperature distribution of object room model was examined by use of basic equations such as airflow by the pressure difference between unit cells, heat flow by air and heat transfer.

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A Estimation of Thermal Fatigue Performance in Three-way Catalyst (삼원 촉매의 열적 내구 성능 평가)

  • Lee, Sung Riong;Cho, Seok-Swoo
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.14 no.1
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    • pp.13-19
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    • 2013
  • This study examines thermal safety on three-way catalyst that dominates 70% among whole exhaust gas purification device in 2003. Three-way catalyst maintains high temperature in interior domain but maintains low temperature on outside surface. Therefore this device shows tensile stress on outside surface. Temperature distribution of three-way catalyst was acquired by thermal flow analysis for predicted thermal flow parameter. Thermal stress analysis for three-way catalysis was performed based on this temperature distribution. Thermal safety of three-way catalyst was estimated by strength reduction factor and failure probability.

Research on the relationship between the thermal characteristics and the type of land cover in Beijing urban area by ASTER data

  • Zhu, QiJiang;Zhang, Xin;Bai, Xianghua
    • Proceedings of the KSRS Conference
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    • 2003.11a
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    • pp.277-279
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    • 2003
  • The study utilizes remote sensing as the main monitoring means. With different spatial high-resolution, multichannel ASTER remote sensing image as the main information in Beijing city zone; with regional border and statistical data as auxiliary factor a study between the thermal space distribution character and the underground medium is analyzed based on the GIS logical algorithm and synthetic analysis technology. Results show thermal forming mechanism and the rule of distribution is mainly related to the underground medium and the change of the city distribution. Different underground medium has different degree and intensity influence on the thermal space distribution. Furthermore, urban greenbelt and water areas can reduce the thermal effect and large-scale greenbelt creates green island effect. In addition, Road net, residential area, population density, heat resources and so on have some positive effect on the thermal distribution, which increase the local temperature and intensity on the other hand. It is important to study the thermal distribution and its related factors, which contributes to the plan, construction and development of the city.

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A Investigation of On-board Thermal Factor (함정 선내의 온열요소에 대한 조사 연구)

  • Jang M.S.;Koh C. D.;Moon I. S.;Lee C. J.;Kim S. H.
    • Journal of the Korean Society for Marine Environment & Energy
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    • v.8 no.1
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    • pp.31-38
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    • 2005
  • This paper is focused on the research of environmental and human factors for a design of PMVbased air conditioning system in the ship. In the results from environmental factor research, it is possible to dissatisfy thermally in the wheel house and communication room of 25 ton and engine room of 100 ton. The clothing and activity in the ship is modified using inland indoor characteristics. Thermal resistance of clothing may be more sensitive to PMV(predicted mean vote) than metabolic rate because of large deviation among maritime polices. The distribution of human factor is right long-tailed than standard normal distribution.

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Analysis on Thermal Environment of Marathon Course in 2011 Daegu World Championship in Athletics (대구 세계육상선수권대회 마라톤 구간의 열환경변화분석)

  • Baek, Sang-Hun;Oh, Sang-Hak;Jung, Yong-Hun;Jung, Eung-Ho
    • Journal of Environmental Science International
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    • v.20 no.7
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    • pp.881-890
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    • 2011
  • In this study, thermal environment changes for a marathon course of IAAF World Championship, Daegu 2011 were modeled to provide improvements of thermal environment, so that runners could have the maximum condition and citizens pleasant streets. The three biggest size of intersections were selected for the study. Envi-met, 3G microclimate model, were used for a thermal environment analysis and three different cases - present status, planting roadside tree scenario, and roof-garden scenario - were compared. The followings are the results of the study. 1. The highest thermal distribution were shown at 1 p.m., but there was no significant difference between a thermal distribution at 1 p.m. and that at 5 p.m. since a heat flux from buildings affects thermal distributions rather than insolation does. 2. Tree planting or adding environmental friendly factors might lead a temperature drop effect, but the effect was not significant for areas covered with impermeability packing materials such as concrete or asphalt (especally, for Site case 2) 3. The combination of tree planting and adding environmental friendly factors also brought a temperature drop effect (Site 1 and 2) and this case showed even better result if green spaces (especially, parks) were closed.

Analysis for Thermal Distribution of Low-voltage Condenser by the Variance of Voltage & Frequency (전압 및 주파수 변화에 따른 저압 콘덴서 열 분포 해석)

  • Kim, Jong-Gyeum
    • Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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    • v.24 no.4
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    • pp.43-49
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    • 2010
  • Power capacitor has been used to compensate for the low power factor of inductive load and to reduce harmonics generated by the power conversion device with reactor. The increase of voltage and current and thermal generation are extremely hard on the life of condenser. Current will be increased, provided that voltage and frequency of condenser increase also. The increase of voltage and frequency justly extends thermal generation. Both act on insulation stress and can afford to premature fault In this paper, we measured thermal distribution of condenser with infrared rays camera in case of variance of voltage and frequency. We were assured that the increase of voltage and frequency produces high heat and exceedingly shortens the life of condenser.

Effect of thermal conductivity degradation on the behavior of high burnup $UO_2$ fuel

  • Lee, Byung-Ho;Koo, Yang-Hyun;Sohn, Dong-Seong
    • Proceedings of the Korean Nuclear Society Conference
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    • 1996.05c
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    • pp.265-270
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    • 1996
  • The temperature distribution in the pellet was obtained from beginning the general heat conduction equation. The thermal conductivity of pellet used the SIMFUEL data that made clear the effect of burnup on the thermal conductivity degradation. Since the pellet rim acts as the thermal barrier to heat flow. the pellet was subdivided into several rings in which the outer ring was adjusted to play almost the same role as the rim. The local burup in each ring except the outer ring was calculated from the power depression factor based on FASER results. whereas the rim burnup at the outer ring was achieved by the pellet averaged burnup based on the empirical relation. The rim changed to the equivalent Xe film so the predicted temperature shooed the thermal jump across the rim. The observed temperature profiles depended on linear heat generation rate. fuel burnup. and power depression factor. The thermal conductivity degradation modelling can be applied to the fuel performance code to high burnup fuel,

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Premature Failure Prevention design of Three-way Catalyst Substrate using DOE (실험계획법을 이용한 삼원촉매담체의 조기 파손 예방 설계)

  • Lee, Dong-Woo;Cho, Seok-Swoo
    • Journal of the Korean Society for Precision Engineering
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    • v.27 no.7
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    • pp.101-108
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    • 2010
  • Domestic three-way catalyst satisfies exhaust gas conversion efficiency or pressure drop etc. but doesn't satisfy thermal durability. Thermal stress analysis for three-way catalyst was performed based on experimental temperature distribution. Thermal safety of three-way catalyst was estimated by safety factor. Aspect ratio variable had the most significant effect on thermal stress. Thickness variable had the least significant effect on thermal stress. Optimal conditions for premature failure prevention of three-way catalyst were as follows : (1) aspect ratio of three-way catalyst : 0.6:1 (2) 2.84mm thick (3) silicon nitride. The safety of Taguchi-optimized three-way catalyst were 4.7 times higher than that of existent three-way catalyst.