• Title/Summary/Keyword: Air-guide

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An Experimental Study on the Performance of a Surface Piercing Propeller in Tunnel (수면관통형 터널 프로펠러의 성능해석을 위한 실험적 연구)

  • Jeong, Seong-Wook;Lee, Seung-Hee
    • Journal of the Society of Naval Architects of Korea
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    • v.43 no.3 s.147
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    • pp.294-303
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    • 2006
  • A surface piercing propeller (SPP) in tunnel has been proposed recently as a new propulsion system for a high speed air cavity ship. The purpose of the present study is to investigate the characteristics of the SPP in tunnel through a series of model tests. A model propulsion system is placed on a dummy body made of Acrylics. The tunnel is divided into two regions by a guide vane extending from the inlet to the center of the propeller shaft. Air has been supplied from an air nozzle placed at the bottom of the dummy body and the changes in propeller performances caused by the air flow are investigated. The measurements are done for open water and in-tunnel conditions, both for fully and partially submerged propeller. The influence of the guide vane configurations on the propeller performance is also studied. The experiments are performed at the variable pressure circulation water channel of Inha University

Influence of the environments on the movement precision of the guide table using externally pressurized porous air bearing (다공질 정압공기 베어링을 이용한 직진 테이블에 있어 주위환경이 움직임 정밀.정확도에 미치는 영향)

  • 한응교;허석환;노병옥
    • Transactions of the Korean Society of Mechanical Engineers
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    • v.12 no.4
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    • pp.721-729
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    • 1988
  • Recently, the precision required by precision manufacturing and machinery related to electronics is within the domain of submicron that it is difficult to evaluate them by traditional measuring equipments and methods. Accordingly, precision of sub 0.1.mu.m super precise position-decision-apparatus and straight-guide air bearing have been researched and they are almost ready to be used. In utilizing straight-guide-table for super-precision-measurement which used externally pressurized porous air bearing as a way of externally pressurized air bearing, the high-precision-straight movement is the most crucial. In this study, the researcher conducted the experimental study with trial manufacture to see how the surrounding temperature and support condition influenced the selection and allocation of the machine composing element which is important to the high-precision-straight movement. The researcher finding showed that when the property of the rail part and support part of the semi-closed slider form is different, the heat generation of the working motor and surrounding temperature influence the high-precision-straight movement significantly and the researcher showed the influence of the condition of central load and eccentric load to the straight movement precision when the support stand of the straight-table was supported by numerical values.

An Experimental Study on the Performance of a Surface Piercing Propeller in Tunnel (수면관통형 터널 프로펠러의 성능해석을 위한 실험적 연구)

  • Jeong, Seong-Wook;Lee, Seung-Hee
    • Special Issue of the Society of Naval Architects of Korea
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    • 2007.09a
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    • pp.107-117
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    • 2007
  • A surface piercing propeller (SPP) in tunnel has been proposed recently as a new propulsion system for a high speed air cavity ship. The purpose of the present study is to investigate the characteristics of the SPP in tunnel through a series of model tests. A model propulsion system is placed on a dummy body made of Acrylics. The tunnel is divided into two regions by a guide vane extending from the inlet to the center of the propeller shaft. Air has been supplied from an air nozzle placed at the bottom of the dummy body and the changes in propeller performances caused by the air flow are investigated. The measurements are done for open water and in-tunnel conditions, both for fully and partially submerged propeller. The influence of the guide vane configurations on the propeller performance is also studied. The experiments are performed at the variable pressure circulation water channel of Inha University.

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A Study on the Optimal Design of Confluent Pipe for Waste Collection Piping System (쓰레기 자동집하시설 이송배관의 합류관 최적설계 연구)

  • Sung, Sun-Kyung;Park, Jun-Gil;Suh, Sang-Ho
    • Korean Journal of Air-Conditioning and Refrigeration Engineering
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    • v.24 no.5
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    • pp.428-432
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    • 2012
  • In the waste collection system, living waste is collected through the piping network. There are many confluent pipes in a piping network. These confluent pipes were often clogged up with waste. The optimal configuration of the confluent pipes has been defined by the design guide. However, nobody know how this design guide were determined. Therefore, in this paper, we found the design data for the confluent pipe configuration in order to avoid the waste clogging in a piping network. The distance between connected point on the confluent pipes should be longer than the previous design guide.

An Experimental Study on the Thermal Performance of Air filled Thermal Diode during Transfer Process (공기를 작동 유체로 하는 열다이오드의 천이 과정중 열성능에 관한 실험적 연구)

  • 황인주;장영근;박이동;김철주
    • Proceedings of the Korea Society for Energy Engineering kosee Conference
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    • 1996.10b
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    • pp.171-175
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    • 1996
  • thermal diode is a device which allows heat to be transferred in one direction by convection due to difference of density of fluid. Vertical plate for heat collection and radiation are of utility for design of thermal diode. It was considered the transient process of air filled thermal diode with guide vane which combined rectangular and parallelogrammic shape enclosures. Gr was kept constantly on 1.60$\times$1010 and error range was $\pm$2% during the experiment. Nu was examined when inclined angle are 15$^{\circ}$and 45$^{\circ}$and, also the experiments was carried out with and without guide vane as well. Specially, The effect of guide vane was sensitive. Developed region inclined angle, which is characteristic of system.

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Effects of an Inlet Guide Vane on the Flowrate Distribution Characteristics of the Nozzle Exit in a Defrost Duct System (성에제거 덕트 입구 가이드베인 형상이 노즐출구 유량분포특성에 미치는 영향)

  • Kim, Duck-Jin;Lee, Jee-Keun
    • Transactions of the Korean Society of Automotive Engineers
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    • v.16 no.4
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    • pp.88-96
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    • 2008
  • Effects of the duct inlet guide vane on the flowrate distribution characteristics of the defroster nozzle exit in a defrost duct system were investigated experimentally to design the optimum heating, ventilation and air conditioning (HVAC) system applied in an automotive compartment. A 3-dimensional hot-wire anemometer system was used to measure the velocity field in the vicinity of the defroster nozzle jet flow and the velocity distributions near the windshield interior surface. At first, two cases of with- and without-duct inlet guide vanes were considered as the test condition, and then three cases of the duct inlet guide vane were tested to determine the optimum guide vane shape and their positions. The arrangement of the duct inlet guide vanes has an effect on the improved flowrate distribution at the defroster nozzle exit and near the windshield interior surface. However, the application of the lots of guide vane to control the flow direction leads to increase the flow resistance, resulting in the decreased flowrate issuing from the defroster nozzle. The shape of the duct inlet guide vane affects not only the flowrate distribution between the driver side and the assistant driver side but also the reduction of the flow resistance in the defrost duct system.

Numerical Analysis for Characteristic of Flow and Disinfection Performance with Variation of Guide Wall in Clearwell (도류벽 형태에 따른 정수지 내 유동 특성과 소독능 변화에 대한 수치 해석적 연구)

  • Lee, Suk-Won;Park, Jun-Jung;Rhee, Gwang-Hoon
    • Proceedings of the SAREK Conference
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    • 2006.06a
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    • pp.767-772
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    • 2006
  • The SWTR(Surface Water Treatment Rule) requires achieving removal 99.9% Giardia and 99.99% Virus. To remove Giardia and Virus, disinfection process is essential process. CT is important index for Disinfection performance. CT value is expressed by CXT. C is represented by disinfection concentration and T is represented by $T_{10}$ which means 90% contact time in clearwell. To improve Disinfection performance, it is desirable to increase $T_{10}$. Primary factor affected $T_{10}$ is flow Pattern. Because guide wall change that flow pattern is uniform, we have installed guide wall to increase $T_{10}$. In this paper, we have performed numerical analysis for clearwell installed symmetric guide wall and center divided guide wall using CFD. We have analyzed flow pattern and $T_{10}$ in each clearwell. And. we compare symmetric guide wall with center divided guide wall in flow pattern and $T_{10}$.

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Development Method of BIM Data Modeling Guide for Facility Management : Focusing on Building Mechanical System (시설물 유지관리를 위한 BIM 데이터 입력기준 개발방안 : 건축 기계설비를 중심으로)

  • Won, Ji-Sun;Cho, Geun-Ha;Ju, Ki-Beom
    • Korean Journal of Air-Conditioning and Refrigeration Engineering
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    • v.25 no.4
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    • pp.216-224
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    • 2013
  • Facility data is created throughout the design and construction phase. But the most facility managers bear significant costs that arise from the lack of interoperability with facility lifecycle. This paper is concerned with the way to collect facility data using BIM technology. The aim of this paper is to suggest BIM data modeling guide for the facility management using the information that need to be delivered from design and construction phase to operation and management phase. The BIM data modeling guide focus on the properties of mechanical equipment. It is to be hoped that this study will contribute to collect facility data from as-built BIM data and to build facility management system database without difficulty.