• Title/Summary/Keyword: side-wall

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Analytical Solution of Two -dimensional Conduction in the Side Wall of a Thermocline System Enclosure (Thermocline 축열조 측벽에서의 열전도 해석)

  • Lee Joon Sik
    • The Magazine of the Society of Air-Conditioning and Refrigerating Engineers of Korea
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    • v.16 no.1
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    • pp.103-108
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    • 1987
  • The heat transfer processes taking place in the side wall of a thermocline enclosure have been analyzed for idealized conditions based on the assumption that, at any instant time, side wall heat transfer processses are independent of the thermocline bulk motion. However, the axial tempera-ture distribution in the thermocline core provides the means for specifying the liquid medium-side boundary condition to the enclosure side wall. A picture is drawn which reflects the side wan response to thermocline bulk motion within the frame work of a quasi-steady analytic approach. For valves of the parameters typical of systems of engineering interest, the analysis shows that a significant amount of heat transfer short - circuiting can take place along the side wall enclosure. This phenomenon is favored by high values of $H_l$ and low values of P and $H_g$ respec-tively. The location of the point of zero normal heat flux on the side wan can be expected to mark, approximately, the region of confluence of two sidewall boundary flows respectively driven by the buoyant effects.

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Effects of sheet and stamping process variables on side wall curl (딥 드로잉 벽면 만곡에 미치는 소재 및 가공조건의 영향)

  • 박기철;한수식;조태현;황상무
    • Proceedings of the Korean Society for Technology of Plasticity Conference
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    • 1998.03a
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    • pp.53-57
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    • 1998
  • In order to investigate the effects of the variables during the stamping process upon the side wall curl behavior, experiments and finite element analyses were done using a 90 degree draw-bending test. The variables considered were the die radius, the forming speed, the restraint force, the lubrication and the sheet grade. The experiments and simulation conditions were selected according to the design of experiment (DOE) approach. The effects of the restraint force, the lubrication and the forming speed were the same for both high strength and mild steels, but the effects of the die radius on the side wall curl were dependent on the magnitude of the die radius and the sheet grade. A straight side wall was observed for both high strength and mild steels when the die radius was about 2∼3 times of the sheet thickness. It was recommended that the restraint force, the forming speed and the friction be increased in order to reduce the side wall curl.

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A 4-axis NC Lettering System for the Side-wall of the Automobile Tire (타이어 사이드판의 문자 가공을 위한 4축 가공 시스템)

  • Lee, Cheol-Soo;Park, Gwang-Ryeol
    • IE interfaces
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    • v.11 no.2
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    • pp.65-78
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    • 1998
  • The letters of the automobile tire are usually engraved on the side-wall. The shape of the side-wall is a sculptured surface generated by the rotational sweeping of a profile curve. The letters laid on the side-wall are usually designed by a 2-dimensional CAD. It is impossible to machine the letters on the surface accurately by 3-axis NC machining, because the axis of cutter should be tilted to align with the normal vector of the surface. In this case. the degree of freedom for the machine is at least four. This paper describes an idea for tool path generation of a 4-axis machine by using the 2-dimensional CAD data of the letters and the surface of the side-wall. This study includes the following procedures; (1) measuring the profile of the side-wall surface and curve-fitting of the measured points. (2) the 'non-parallel projection' of the letters on the side-wall, and (3) an inverse kinematics of the 4-axis lettering machine. Procedures in this paper are programmed in C-language on Windows95 environment. With a PC based CNC controller and a 4-axis lettering machine. these are tested sucessfully for the practical use.

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EFFECT OF THE SHAPE OF IMPINGEMENT PLATE ON THE VAPORIZATION AND FORMATION OF FUEL MIXTURE IN IMPINGING SPRAY

  • Kang, J.J.;Kim, D.W.;Choi, G.M.;Kim, D.J.
    • International Journal of Automotive Technology
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    • v.7 no.5
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    • pp.585-593
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    • 2006
  • The effect of the shape of the side wall on vaporization and fuel mixture were investigated for the impinging spray of a direct injection(DI) gasoline engine under a variety of conditions using the LIEF technique. The characteristics of the impinging spray were investigated under various configurations of piston cavities. To simulate the effect of piston cavity configurations and injection timing in an actual DI gasoline engine, the parameters were horizontal distance from the spray axis to side wall and vertical distance from nozzle tip to impingement plate. Prior to investigating the side wall effect, experiments on free and impinging sprays for flat plates were conducted and these results were compared with those of the side wall impinging spray. For each condition, the impingement plate was located at three different vertical distances(Z=46.7, 58.4, and 70 mm) below the injector tip and the rectangular side wall was installed at three different radial distances(R=15, 20, and 25 mm) from the spray axis. Radial propagation velocity from spray axis along impinging plate became higher with increasing ambient temperature. When the ambient pressure was increased, propagation speed reduced. High ambient pressures tended to prevent the impinging spray from the propagating radially and kept the fuel concentration higher near the spray axis. Regardless of ambient pressure and temperature fully developed vortices were generated near the side wall with nearly identical distributions, however there were discrepancies in the early development process. A relationship between the impingement distance(Z) and the distance from the side wall to the spray axis(R) was demonstrated in this study when R=20 and 25 mm and Z=46.7 and 58.4 mm. Fuel recirculation was achieved by adequate side wall distance. Fuel mixture stratification, an adequate piston cavity with a shorter impingement distance from the injector tip to the piston head should be required in the central direct injection system.

An Experimental Study on the Cylinder Wall Temperature Characteristics for Load Variations in a Gasoline Engine (가솔린엔진의 부하(負荷)에 따른 실린더 벽면 온도특성(溫度特性)에 관(關)한 연구(硏究))

  • Kwon, K.R.;Ko, J.K.;Hong, S.C.
    • Journal of Power System Engineering
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    • v.3 no.1
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    • pp.16-22
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    • 1999
  • The purpose of this study is to prevent the stick, scuffing, scratch between piston and cylinder, is to contribute the piston design such as piston profile, clearance by calculating reaction force by over-lap of piston skirt, as measuring the temperature distributions of cylinder wall. The experiment has been peformed to obtain data during actual engine operation. Temperature gradient in peripheral and axial distributions of cylinder wall according to torque and speed of engine were measured by use of an 800cc class gasoline engine. The results obtained are summarized as follows ; 1) The temperature of cylinder wall at TDC was about $50{\sim}75^{\circ}C$ higher than temperature of cooling water. 2) The rear side temperature of top dead center was $141^{\circ}C$(1/4 load) in axial distribution, whereas the rear side of midway position temperature was $98^{\circ}C$. 3) The temperature of cylinder wall increased in according to rising temperature of cooling water. 4) The thrust side temperature of cylinder wall was about $15^{\circ}C$ in all load test. 5) The rear side temperature of top dead center was $159^{\circ}C$ (1/2 load) in peripheral distribution, it was about $39^{\circ}C$ higher than thrust side temperature.

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A Study on the Characteristics of Building the Japanese Castle at the Period of Japanese Invasion of Korea in 1592 and in 1597 (임진왜란과 정유재란시기 왜성 축조방법에 대한 연구)

  • Lee, Hyung-Jae
    • Journal of architectural history
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    • v.18 no.1
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    • pp.31-49
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    • 2009
  • Periodically, the Japanese Castle was created in the domestic of Japan and then 2 Invasions into Chosun was started. The Japanese Castle in the domestic of Japan was repaired several times by the building boom of castle before & after 2 invasions and so the initially-built type of castles was changed. Accordingly, there are much difficulties to understand the original shape of Japanese Castle. Through the Japanese Castle within Korea called as the fossil of Japanese Castle, I would like to examine & consider its building period and characteristics. The terminology called as [Two Side Stone's Wall] is that of castle which is not acknowledged in the Japanese Academic Circles. However, it means the two-fold wall of Japanese Castle which was widely applied to the fortification way in the Age of Japan Edo. The terminology of [Sori] says the stonework curve in the corner of Japanese Castle which is indicated best in the Japanese Castle. It calls the curve as like the fan frame. [Curb Stone's Wall] says the type of castle wall constructed with over 1 face in wall body of Japanese Castle. (1) About classifying the construction period of Japanese Castle, the curb stone's wall and the castle having no two side stone's wall must consider the building period as that of Japanese Invasion of Korea in 1592. If there was [Sori], the two-side stone's wall was used and the place which supported the documentary data, in particular, the place having the record of contraction is considered to be confirmed as the castle constructed in the period of Japanese Invasion of Korea in 1597. (2) The two-side-type stone's wall shown in the Modern Japanese Stone Castle is difficultly considered to be generated from the Japanese Castle at the period of Japanese Invasion of Korea in 1592 and in 1597. (3) The beautiful [Sori] shown in the Modern Japanese Stone Castle was started from the Japanese Castle of Korea at the period of Japanese Invasion of Korea in 1597. It is difficultly considered which its indication was firstly generated by the Chaesung-Folded Segment Structure.

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Experiments of Wave Heights in front of a Perforated Wall under Obliquely Incident Waves:Monochromatic Wave Conditions (경사입사파 조건에서 유공벽 전면의 파고분포에 대한 실험:규칙파 조건)

  • Lee, Jong In;Kim, Young Taek
    • KSCE Journal of Civil and Environmental Engineering Research
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    • v.32 no.5B
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    • pp.301-312
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    • 2012
  • This study investigates the wave height distributions in front of a perforated wall generated by obliquely incident monochromatic waves through laboratory experiments conducted in a wave basin. Attention is paid to the difference or similarity between a plain wall and a perforated wall. And the investigation is focused on the chamber width and side wall effects of a perforated wall on the propagation characteristics of waves. The main results of this study show that the normalized wave height along a perforated wall is a significant difference compare to a plain wall cases. The side wall in the chamber suppresses the growth of the stem waves.

A study of light output characteristics with various refractive indices and geometrical structures of the GaN based light-emitting device encapsulants (질화갈륨계 발광소자 봉지재의 굴절률 및 곡률 변화에 따른 광 출력 특성 연구)

  • Kim, Heyong-Jin;Yoo, Jin-Yeol;Kang, Young-Rae;Kim, Jae-Pil;Kwak, Joon-Seop
    • Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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    • v.26 no.7
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    • pp.1-8
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    • 2012
  • In this paper, we improved the light extraction efficiency by structural change of LEDs on conventional LEDs. We simulated the LEDs light emission as functions of LED side wall angle, various refractive indices the geometrical structures and analyzed the condition improved the light efficiency. We present the results of experimerns and simulations for light output power from LEDs for various refractive indices and the geometrical structures of the LED encapsulants. When the side wall angle range was from 40[$^{\circ}$] to 30[$^{\circ}$], the LED emission increased. LED side wall angle onto LED using the simulation system with a fine tuning of the structure of the LEDs side wall angle is fabricated. Additionally, we changed the side wall angle of LED package with spherical structure and flat structure. The result of spherical structure ray tracting is higher compared with flat structure about 14[%].

A Study on the Breakdown Characteristics of High Voltage Device using Field Limiting Ring and Side Glass Insulator Wall (전계제한테와 측면 유리 절연층을 사용한 고내압 소자의 항복 특성 연구)

  • Huh, Chang-Su;Chu, Eun-Sang
    • Proceedings of the KIEE Conference
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    • 1995.07c
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    • pp.1072-1074
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    • 1995
  • Zinc-Borosilicate is used as a side insulastor wall to make high breakdown voltage with one Field Limiting Ring in a p-n junction. It is known that surface charge can be yield at the interface of Zinc-Borosilicate Glass/Silicon system. When the glass is used as a side insulator wall, surface charge varied potential distribution and breakdown voltage improved more than 660V without using more FLR.

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Fabrication of electrodes on mcirochannel side wall using shadow evaporation effect (샤도우 증착 효과를 이용한 마이크로 채널내 측벽 전극 제작)

  • 강길환;김규만
    • Proceedings of the Korean Society of Precision Engineering Conference
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    • 2004.10a
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    • pp.1462-1465
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    • 2004
  • A new method to fabricate metal electrodes on side wall of the microchannel is presented. Coulter counter allows to count the number of cell passing through the microchannel by detecting impedance variation between two electrodes. The relative position of two electrodes is important for sensitivity of impedance measurement. 100nm thick Al electrodes are deposited on the channel side wall by means of shadow evaporation.

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