• Title/Summary/Keyword: Partition wall

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Experimental Study for Natural Convection Flow in an Inclined Partitioned Square Enclosure (격판이 존재하는 경사진 정사각형 밀폐공간 내의 자연대류유동에 관한 실험적 연구)

  • Kim, Gwang-Hui;Kim, Yu-Gon
    • Transactions of the Korean Society of Mechanical Engineers B
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    • v.26 no.2
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    • pp.310-317
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    • 2002
  • In the present study, an experimental study of natural convection in a partitioned 2D square enclosure has been carried out. The square enclosure consist of two adiabatic vertical walls and the upper cold and the lower hot walls. A partition is positioned perpendicularly at the center of the left vortical insulated wall. The PIV measurements were performed with the variations of Rayleigh number, partition length and inclination of the enclosure. The working fluid is water with Prandtl number of 6.996 at 20$\^{C}$. The captured images were analyzed by using a cross-correlation (two-frame/single-exposure) PIV method.

Oscillatory Motion of Natural Convective Flow in Partially Divided Square Enclosure (수평격판을 갖는 4각형 밀폐공간내에서 자연대류의 진동유동)

  • 김점수;정인기;송동주
    • Transactions of the Korean Society of Mechanical Engineers
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    • v.16 no.10
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    • pp.1963-1970
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    • 1992
  • An oscillatory motion of the natural convection in a two dimensional, partially divided square enclosure heated from below, and fitted with a partition is investigated numerically. The enclosure was composed of the lower hot and the upper cold horizontal walls and the adiabatic vertical walls, and a partition was situated perpendicularly at the mid-height of the one vertical insulated wall. The governing equations are solved by using the finite element method with Galerkin method. The computations were performed with the variation of the length and the thermal conductivity of the partition, and Rayleigh number based on the temperature difference between horizontal walls and the enclosure height with water(Pr=4.95). also, the effect of the inclination angles was studied for the transition to the oscillating flow. As the results, it was found that the intensity and frequency of oscillatory motion were affected significantly by the Rayleigh number and the length of partition. The effect of oscillatory motion was weaken with the increase of the thermal conductivity of partition. The inclination angle for the transition was raised with the increase of Rayleigh number and the length of partition.

Effect of Sound Damping Sheet on Sound Transmission Loss in Building Structure (건축 구조물에의 차음시트 적용)

  • Kim, Sang-Ryul;Kim, Jae-Seung;Kim, Hyun-Sil;Kang, Hyun-Ju;Mah, Kyung-Up;Han, Mun-Sung
    • Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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    • 2000.06a
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    • pp.1723-1728
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    • 2000
  • This paper deals experimentally with the effect of the sound-damping sheet on building wall system; brick wall, light wall panel, and gypsum board. Experimental results show that when the sound-damping sheet is attached on wall systems, the mass and/or damping effects result in increasing of STL of wall system depending on the characteristics of the original partition. It is pointed out that the performances of sound damping sheets must be presented with specific wall structures that applied, not by the sound transmission loss of the sheet itself.

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A Study on the Operating System of the Architectural Standard Scale of Length(尺度, Korean foot) used in the Hwasong City Wall in the 18th Century (척도운용체계를 통해 본 18세기 화성건축의 건축구성에 관한 연구)

  • Lee, Ho-Rak;Lee, Sang-Hae
    • Journal of architectural history
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    • v.6 no.2 s.12
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    • pp.65-77
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    • 1997
  • The Hwasong City Wall was built for three years(1794-1796), but the real construction term was taken only 28 months. The wall and the buildings on the wall were built simultaneously, and the esttimated construction cost was highly restricted. These conditions were main factors for considering the high efficiency of construction productivity. This study examines these factors that are reflected in the operating system of the architectural standard scale of length, the architectural composition system in the Hwasong City Wall to reduce the construction cost. Through the study, following factors are found. 1.The rule of multiple proportion is found in the relationship between the partition distance, that is, span and the height of the girder which is related to the productivity of ready-made building members. 2.The ruling grade system of scale in the component members is found in the chang-bang(창방, penetration members)

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Effect of Heat/Mass Transfer in the turbine blade internal passage with various rib arrangement (회전하는 터빈 블레이드 이차유로내 요철 배열이 열/물질전달에 미치는 영향)

  • Lee, Sei-Young;Cho, Hyung-Hee
    • Proceedings of the KSME Conference
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    • 2001.11b
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    • pp.22-29
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    • 2001
  • The present study investigates the effects of various rib arrangements and rotating on heat/mass transfer in the cooling passage of gas turbine blades. The cooling passage has very complex flow structure, because of the rib turbulator and rotating effect. Experiments and numerical calculation are conducted to investigate the complex flow structures and heat transfer characteristics; the numerical computation is performed using a commercial code, FLUENT ver.5, to calculate the flow structures and the experiments are conducted to measure heat/mass transfer coefficients using a naphthalene sublimation technique. For the rotating duct tests, the test duct, which is the cross section of is $20mm\times40mm$ (the hydraulic diameter, $D_h$, of 26.7 mm, has two-pass with $180^{\circ}$ turning and the rectangular ribs on the wall. The rib angle of attack is $70^{\circ}$ and the maximum radius of rotation is $21.63D_h$. The partition wall has 10 mm thickness, which is 0.5 times to the channel width, and the distance between the tip of the partition wall and the outer wall of the turning region is 26.7 mm $(1D_h)$. The turning effect of duct flow makes the very complex flow structure including Dean type vortex and high turbulence, so that the heat/mass transfer increases in the turning region and at the entrance of the second pass. The Coriolis effect deflects the flow to the trailing surface, resulting in enhancement of the heat/mass transfer on the trailing surface and reduction on the leading surface in the first pass. However, the opposite phenomena are observed in the second pass. The each rib arrangement makes different secondary flow patterns. The complex heat/mass transfer characteristics are observed by the combined effects of the rib arrangements, duct rotation and flow turning.

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The Investigation of Structural Behavior with Variations in the Lower Stories of Complex Buildings using Push-over Analysis (Push-over 해석을 사용한 복합구조물의 하부골조 층수변화에 따른 거동분석)

  • 강병두;전대한;김재웅
    • Proceedings of the Computational Structural Engineering Institute Conference
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    • 2001.04a
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    • pp.398-405
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    • 2001
  • Upper wall-lower frame(complex building) can be divided into three partition, namely, upper wall, lower frame, and transfer system which link two partitions. The purpose of this study is to investigate the elasto-plastic response characteristics of structures with variation in the stories of lower frame of complex buildings. The conclusions of this study was following; 1) In the push-over analysis for vertically irregular building, the distribution of lateral forces is judged which consider the effects of higher mode. 2) In proportion as the stories of lower frame increase inter-story displacement of lower frame increased, but that of upper wall decreased. 3) The appearance of yielding hinge with variations in the lower stories of complex buildings differed in lower frame of each model, but was almost the same in upper wall.

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Comparative Study on the Structure of Vascular Cambium in Some Salicaceae (수종의 버드나무과 유관속 형성층의 구조에 관한 비교연구)

    • Korean Journal of Plant Resources
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    • v.11 no.3
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    • pp.326-334
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    • 1998
  • Vascular cambium in 16 species of Salicaceae is nonstoried in all of them and is made up of fusiform and ray initials. The growth of cambial girth occurred by pseudotransverse division of fusiform initials and subsequent apical intrusive growth of daughter initials. The measurements of fusiform initials in tangerntial sections have revealed that the average length varies from 252.2-437.1${\mu}{\textrm}{m}$ in investigated species, with the maximum being in Populus euramericana and the minimum in Salix purprea var. Multinervis. The length of fusiform initials depends on the length of the tapering end wall , therefore, the longer the length of the tapering end wall, therefore, the longer the length of the taperding end wall, the longer the length of fusiform initials. Ray initials have their own size, magnitude, and frequency of occrrence in each species. The relative proportion of ray initials fall about 15.0-24.5% in Salicaceae. Shrubby species of Salix have a lower ratio of ray initials than the species which possess wider trunks. New ray initials are originated from cut off the side or the end of fusiform initials and central partition of a fusiform initials.

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A Study on Improvement of the Performance of Pulsed AC Ion Bar (2) (바 형태 정전기제거장치의 정전기제거성능 향상을 위한 연구 (2))

  • Lee, Dong Hoon;Choi, Dong Soo;Kim, Sang Min;Park, Jin Chul
    • Journal of the Korean Society of Safety
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    • v.29 no.6
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    • pp.40-45
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    • 2014
  • In display such as LCD, LED, and AMOLED or semiconductor related industries are required to have static ionizer in order to produce reliable goods. The most general type of ionization is called, "corona discharge" that has a slight chances to generate unequal and unstable amount of each +/- ion to the target object. Then, the ionization performance will drastically decrease and end up with quality deterioration problem. continually "A study on the improvement of the performance of pulsed AC ion bar(1)", we have studied consecutive study to improve the current issue via appling "partition wall" at air nozzle surrounding. The results were that the charge decay time and the ion balance was maintained the satisfied range that was within 5 second and ${\pm}50$ V for a 180 days period of time. In additions, the contamination status on the electrode surface was investigated for a 180 days. The little particles was deposited on the electrode surface.

A Study on the Transformation of Openings in MyungRyun-Dangs of HyangGyo Architecture Located in Kyungbuk Province - Focused on the partition wall between Daechung and Bang - (경북지역 향교건축(鄕校建築) 명륜당(明倫堂)의 개구부(開口部) 변천(變遷)에 관한 연구 -대청(大廳)과 방(房) 사이의 경계벽(境界壁)을 중심으로-)

  • Chung, Myung-Sup;Kim, Il-Jin
    • Journal of architectural history
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    • v.1 no.1 s.1
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    • pp.33-43
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    • 1992
  • The purpose of this study is to investigate the transformation of openings installed on the partition wall between Daechung and Bang, through the case study on MyungRyunDangs of 19 HangGyos in Kyungbuk province. The way to carry out this study was to look through existing situations and to find out transformed traces of the openings in terms of their locations on several floor types. The transformation of the openings was analyzed chronologically into two cases of 'before 18C' and 'after 18C'. i) Before 18C ; the early type had double swing window on the front column spacing and single swing door on the rear, and the later type had swing door on the front column spacing and on openings on the rear. ii) After 18C; the earlist type was the same as the later type of 'before 18C', the next type had swing doors on both the front and the rear column spacing, and the last type had Sabunhap-swing door on the column spacing, iii) Through those transformations, the windows gradually replaced by the doors in the openings.

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