• Title/Summary/Keyword: Louver

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The Study on the Thermal Performance of the Automobile Radiators. (자동차용 라디에이터의 방열량에 관한 연구)

  • 최인규;이진호
    • Transactions of the Korean Society of Mechanical Engineers
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    • v.1 no.2
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    • pp.95-103
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    • 1977
  • The expermental research was carried out to investigate the thermal performance of the locally manufactured radiators for 1300cc automobiles. The choice of .epsilon. value (the ratio of water tube surface area to the total heat transfer area ) resulted in remarkable difference in their performance including the Louver effect, the overrall heat tranfer coefficient and the heat dissipation capability.

Heat Transfer and Friction Characteristics of Louver Fin and Tube Heat Exchangers under Wet Conditions (루버핀-관 열교환기의 습조건에서의 열전달 및 마찰특성에 대한 실험 연구)

  • Kwon, Young Chul;Chang, Keun Sun
    • Applied Chemistry for Engineering
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    • v.19 no.1
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    • pp.73-79
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    • 2008
  • An experimental study was conducted to investigate the effect of a tube row, a fin pitch and an inlet humidity on air-side heat and mass transfer performance of louvered fin-tube heat exchangers under wet conditions. Experimental conditions were varied by three fin pitches, two rows, two inlet relative humidities. Experimental results showed that the heat transfer performance decreased and the friction increased with the decrease of fin pitch, for 2 row heat exchanger. The effect of fin pitch on heat transfer performance was negligible with 3 row heat exchanger. The changes in relative humidity was not affected heat transfer and friction. However, the mass transfer performance was slightly decreased with the increase of relative humidity and with the decrease of fin pitch. The mass transfer performance of the louvered fin-tube heat exchanger decreased with the decrease of the fin pitch and was different according to the number of tube row.

Comparison of Heat Transfer Performance and Pressure Drop of Fin-Tube and Aluminum Heat Exchangers (핀-튜브 열교환기와 알루미늄 열교환기의 전열성능과 압력강하 특성비교)

  • Chang, Keun-Sun;Lee, Hyun-Su;Kim, Jae-Duck
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.10 no.2
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    • pp.222-229
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    • 2009
  • This study presents comparison of heat transfer and air side friction characteristics in a condenser condition of air conditioner between Louver fin-tube heat exchangers and aluminum parallel heat exchangers. All experiments are performed using an air-enthalpy type calorimeter, which is designed based on the method described in ASHRAE standards. The air velocities crossing the heat exchanger tubes are varied from 0.7 to 1.6 m/s with 0.3 m/s interval, maintaining air dry temperature and relative humidity at $20^{\circ}C$ and 60% respectively. Water temperature and flow rate inside the tube are $70^{\circ}C$ and 10 LPM, respectively. Experimental results show that the heat transfer performances of aluminum heat exchangers are 17-163% higher than those of Louver fin-tube heat exchangers based on the data per unit volume, mass, and heat transfer area, whereas air side pressure drops of aluminum heat exchangers are 19-81% lower.

Multi-dimensional wind vibration coefficients under suction for ultra-large cooling towers considering ventilation rates of louvers

  • Ke, S.T.;Du, L.Y.;Ge, Y.J.;Tamura, Y.
    • Structural Engineering and Mechanics
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    • v.66 no.2
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    • pp.273-283
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    • 2018
  • Currently, the dynamic amplification effect of suction is described using the wind vibration coefficient (WVC) of external loads. In other words, it is proposed that the fluctuating characteristics of suction are equivalent to external loads. This is, however, not generally valid. Meanwhile, the effects of the ventilation rate of louver on suction and its WV are considered. To systematically analyze the effects of the ventilation rate of louver on the multi-dimensional WVC of ultra-large cooling towers under suctions, the 210 m ultra-large cooling tower under construction was studied. First, simultaneous rigid pressure measurement wind tunnel tests were executed to obtain the time history of fluctuating wind loads on the external surface and the internal surface of the cooling tower at different ventilation rates (0%, 15%, 30%, and 100%). Based on that, the average values and distributions of fluctuating wind pressures on external and internal surfaces were obtained and compared with each other; a tower/pillar/circular foundation integrated simulation model was developed using the finite element method and complete transient time domain dynamics of external loads and four different suctions of this cooling tower were calculated. Moreover, 1D, 2D, and 3D distributions of WVCs under external loads and suctions at different ventilation rates were obtained and compared with each other. The WVCs of the cooling tower corresponding to four typical response targets (i.e., radial displacement, meridional force, Von Mises stress, and circumferential bending moment) were discussed. Value determination and 2D evaluation of the WVCs of external loads and suctions of this large cooling tower at different ventilation rates were proposed. This study provides references to precise prediction and value determination of WVC of ultra-large cooling towers.

Wind tunnel study of wind loading on rectangular louvered panels

  • Zuo, D.;Letchford, C.W.;Wayne, S.
    • Wind and Structures
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    • v.14 no.5
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    • pp.449-463
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    • 2011
  • Drag forces on a rectangular louvered panel, both as a free-standing structure and as a component in a generic low-rise building model, were obtained in a wind tunnel study. When tested in a building model, the porosity ratio of the wall opposite the louvered panel was varied to investigate its effect on the loading of the louvered panel. Both mean and pseudo-steady drag coefficients were obtained. Comparisons with the provisions for porous walls in contemporary loading standards indicate that for some opposite wall porosity ratios, the standards specify significantly different wind loads (larger and smaller) than obtained from this wind tunnel study.

The Effect on the Heating and Cooling Load of Building by Slat Angle Variation of Venetian Blind (베네치안 블라인드의 슬래트 각도변화가 건물의 냉난방 부하에 미치는 영향)

  • Cho, S.H.;Shin, K.S.
    • Korean Journal of Air-Conditioning and Refrigeration Engineering
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    • v.7 no.2
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    • pp.171-183
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    • 1995
  • Generally, among many kinds of shading devices such as venetian blind, sunscreen, louver and curtain, venetian blind is using widely because the mechanism is so simple and easy to use solar insolation by controlling the slat angle. Analysis of time dependent heat transfer through the window with venetian blind is very important in order to use it effectivly. Therefore, in this study, theoretical thermal analysis method was developed to analyze time dependent heat transfer through a double pane window with and without venetian blind, and was made one module of TRNSYS(A Transient Simulation Program)program. By this way, it was analyzed that how much the variation of slat angle, slat colour and slat absorptivity of venetian blind would be affected on the heating and cooling load of building, and also which colour and angle of slat was optimal for the heating and cooling load of building.

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A Study on Ventilation Characteristics of Cargo-oil pump room (화물유 펌프실의 환기특성에 관한 연구)

  • 박찬수;조대환
    • Journal of Advanced Marine Engineering and Technology
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    • v.24 no.1
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    • pp.134-141
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    • 2000
  • In this study, a scaled model chamber was built to investigate ventilation characteristics of the Under floor Air-conditioning System. Experimental study was performed in model for cargo-oil pump room with inlet and outlet by visualization equipment with laser apparatus. Instant simultaneous velocity vectors at whole field were measured by 2-D PIV system(CACTUS'2000) which adopted two-frame grey-level cross correlation algorithm. The flow pattern reveals the large scale counterclockwise forced-vortex rotation from upside louver to lower scupper toward diagonal corner and also found small eddies at bottom layer

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Technique Development Tendency for Ice Class Louver (아이스 클래스(Ice-Class)루버의 기술개발 동향)

  • Seo, Kwang-Oog;Shim, Eui-Bo;No, Byeang-Su;Cho, Dae-Hwan
    • Proceedings of the Korean Institute of Navigation and Port Research Conference
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    • 2015.07a
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    • pp.41-42
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    • 2015
  • 극해 지역은 채굴가능 매장량의 30% 정도의 각종 천연자원이 매장되어 있으며 기후변화로 인해 북극해 항로를 이용한 운항 및 자원의 수송과 저장을 위해 빙해 선박과 극지용 해양구조물의 수요가 증가하고 있다. 이 연구에서는 아이스 클라스 등 방한기술에 근거하여 빙해 선박에 탑재되는 루버의 기술개발 동향에 대해 고찰 하였다.

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3-dimensional Numerical Analysis on Thermal Performance of an Oil Cooler (3차원 오일쿨러 방열성능 수치해석)

  • Park, Sang-Jun;Lee, Young-Lim
    • Proceedings of the KAIS Fall Conference
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    • 2010.11b
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    • pp.944-946
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    • 2010
  • 열교환기는 공조 및 기타 산업현장에서 많은 수요가 창출되고 있는데 본 논문에서는 3차원 수치해석을 이용하여 수송기계의 오일쿨러나 연료쿨러에 쓰이는 전형적인 열교환기에 대한 방열 성능을 해석하였다. 열교환기의 핀 타입 중 wavy 및 louver에 대하여 열교환기 성능 실험 데이터를 이용하는 3차원 열교환기 모델을 완성하고 통과 풍량에 따른 열교환량을 예측하였다. 이는 열교환기를 통과하는 풍속이 균일하지 않을 때 열교환량을 예측할 수 있어 설계 정확성 향상에 기여할 수 있다.

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A Study on the Lighting Environment Improvement of the VDT Workspaces in Computer Room (컴퓨터실에 있어서 VDT작업공간의 조명환경 개선에 관한 연구)

  • Jung, Jin-Hyun
    • Journal of the Korean Institute of Educational Facilities
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    • v.4 no.3
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    • pp.31-39
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    • 1997
  • The purpose of this study was to improve the lighting environment of the VDT workspaces in computer laboratory. This study was carried out through the field measurements on the computer laboratory and a survey using the questionnaire about the VDT workspaces. The major findings of the study were as follows: (1) It was unbalanced among the illumination, luminance, and color distributions in the the VDT workspaces. (2) The difference of brightness between the CRT screen and its surroundings have presented on the whole unbalanced. (3) It was proved that the artificial light source of the ceiling lighting should use the parabolic louver luminaire limiting the radiant luminance.

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