• Title/Summary/Keyword: 유기유동

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A Study on the Degradation of Isopropyl Alcohol with $TiO_2$-coated Plastic Optic Fibers (광촉매 코팅 광섬유의 IPA 분해 특성 연구)

  • Yu Dong-Si;Joo Hyun-Ku;Ha Jin-Wook
    • Proceedings of the KAIS Fall Conference
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    • 2005.05a
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    • pp.283-286
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    • 2005
  • 본 연구에서는 광촉매 $TiO_2$/p-25를 POF에 코팅하여 IPA 분해 활성을 고찰한 결과, 코팅 시 용매의 조건은 에탄올에서 IPA의 분해효율이 가장 우수하였고 무기바인더(KR-400), 유기바인더(A-9540) 및 무$\cdot$유기 복합바인더(GPTMS, TMOS)중에서 유기 바인더인 A-9540을 사용했을 때 효율이 가장 우수한 것으로 나왔다. 유기 바인더는 광분해반응에 의하여 바인더 자체가 분해되고 무기 바인더는 부착성이 떨어졌다. 유$\cdot$무기 복합 바인더 중에서 광분해 효율이 뛰어난 TMOS를 바인더로 선정하여 TMOS/P-25의 비율을 0.05부터 1로 바꾸어 광분해 실험을 수행한 결과, 바인더로써 TMOS의 첨가는 IPA분해 효율을 낮게 하였다.

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Self-discharge characteristic analysis of Vanadium Redox Flow Battery on temperature and SOC (온도와 SOC에 따른 바나듐 산화 환원 유동 배터리의 자가 방전 특성 분석)

  • Han, Dongho;Kim, Jonghoom;Yoo, Kisoo
    • Proceedings of the KIPE Conference
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    • 2018.07a
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    • pp.231-233
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    • 2018
  • 바나듐 산화 환원 유동 배터리는 긴 수명주기와 높은 에너지효율로 리튬 이온 배터리를 대체할 차세대 배터리로 주목받고 있다. 에너지가 저장되는 전해질을 순환시키면서 충전 과방전이 이루어진다는 이차전지 인 만큼 유지 보수 비용을 획기적으로 절감할 수 있고 사용자의 요구조건에 따라 출력과 에너지 용량을 매우 쉽게 조절할 수 있다는 장점이 있다. 하지만, 바나듐 산화 환원 유동 배터리를 다양한 어플리케이션에 적용하기 위하여 바나듐 배터리 운용에서 여러 가지 요소들을 고려하여야 한다. 본 논문에서는 충전 및 방전을 지속했을 때의 용량 감소하는 바나듐 산화 환원 유동 배터리의 특성을 고려하여 가장 까다로운 문제 중 하나인 휴지 기간에서의 자가 방전에 대해 온도와 SOC에 따라 특성 분석을 실시하였다.

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A Study on Effect of Flow Characteristics for Turbine Impeller Shape (Turbine Impeller 형상이 유동특성에 미치는 영향에 관한 연구)

  • Jeon, Eon-Chan;Youn, Gi-Ho;Kang, Chang-Hun
    • Journal of the Korean Society of Manufacturing Process Engineers
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    • v.13 no.4
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    • pp.36-43
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    • 2014
  • Recently, research has been conducted to develop the ORC (organic Rankine cycle), to recover waste heat from facilities such as industrial plants ultimately to create mechanical or electrical energy. The ORC system consists of a heat exchange, a condenser, a pump and a boiler. In this paper, 84 flow analyses were conducted with 21 cases and three variables, i.e., a number of large wings, a number of small wings, and RPMs. R245fa was used as a refrigerant. The flow cavitation phenomenon was investigated through a flow analysis, and a flow stream analysis was conducted.

Vertical Convection Flow around V-Shaped Structures in Uniform Current (조류 중에 놓인 V-형 구조물 주위의 연직순환류에 대한 연구)

  • Yang, Chan-Kyu;Hong, Keyyong
    • Journal of the Society of Naval Architects of Korea
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    • v.34 no.4
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    • pp.148-157
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    • 1997
  • In this paper, the flow around a V-shaped plate positioned against horizontal flow is numerically simulated by using finite volume method and experimentally visualized in two dimensional tank by dye injection method. The upwelling flow artificially induced by V-shaped plate mixes the stratified stagnant flow. It can be applied to mitigate the eutrophication and stratification of sea in the vicinity of offshore structures.

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A Study on the Characteristics and Cleanliness of Fluidic Strip Process of Environment-Friendly Aqueous Stripper (친환경 수계 박리액의 유동박리 공정 특성 및 청정성 연구)

  • Lee, Ki-Seong;Lee, Jaeone;Kim, Young Sung
    • Clean Technology
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    • v.24 no.3
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    • pp.175-182
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    • 2018
  • In this research, we investigated the cleanliness by optimizing the water content of the aqueous stripper in fluidic strip process. The stripping properties of the photoresist with optimized aqueous stripper were compared with the commercial organic stripper. The stripping performance was evaluated by electrical and optical characteristics on the surface of the transparent electrode that compare with stripped the transparent electrode surface and the rare surface before patterning by the photoresist. As a result of the photoresist stripping process of the organic stripper and the aqueous stripper optimized for water content, the aqueous stripper exhibited better electrical and optical characteristics than the organic stripper. In the case of the fluidic strip process with organic stripper, the photoresist dissolves in the stripper solution during stripping which can cause re-adsorption by contamination. Whereas that the aqueous stripper under development seems to decrease the photoresist dissolution in the stripper solution. Because the cyclodextrin contained in the stripper captures organic photoresist into hall of cyclodextrin which stripped through swelling and tearing. The photoresist residue captured by the cyclodextrin can be filtered. After the fluidic stripping process by different chemical stripping mechanism, the cleanliness of the organic stripper and aqueous stripper was compared and analyzed.

On the Viscous Flow Around Breaking Waves Generated by a Submerged Cylinder(Part 3 : Survey of Flow Field Using PIV Technique) (몰수실린더에 의하여 생성되는 쇄파주위 점성유동의 고찰(제3부 : PIV를 이용한 순간유동장 해석))

  • B.S. Hyun;Y.H. Shin;K.S. Choi
    • Journal of the Society of Naval Architects of Korea
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    • v.37 no.2
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    • pp.38-45
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    • 2000
  • A breaking-wave caused by a cylinder moving under the free-surface is studied, which is designed to unveil the interaction between breaker and cylinder using PIV at CWC. The detailed structures of the vortical flow is obtained from the velocity field measured by PIV technique. The vorticity distribution behind the breaker and originated from the breaker. It has been obvious that the vortices from breaker greatly affect the whole wake field at S/D=1. Certainly PIV was confirmed to be a very versatile means to investigate the complex flow fields such as breaking wave.

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Study on the Vortex Shedding Phenomena Near Free Surface (자유수면 근처에서의 보오텍스 방출 현상에 관한 고찰)

  • Seok-Won Hong;Pan-Mook Lee
    • Journal of the Society of Naval Architects of Korea
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    • v.28 no.2
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    • pp.118-131
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    • 1991
  • The effects of free surface on vortex shedding phenomena around a bluff body were studied by both numerical simulation and flow visualization experiments. A vortex method, which approximates the vorticity field as the sum of discrete vortices; was used for the numerical simulation. Flow visualization experiments were performed in the KRISO cavitation tunnel. Hydrogen bubble was used as illumination material. Free surface elevation was also measured during experiments. The hydrodynamic drag and lift were predicted by numerical simulation. The predicted period of vortex shedding was compared with the results of experiments.

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The Numerical Calculation of the Velocity Components Induced by a Havelock Source (Havelock Source에 의한 유기 속도 성분의 수치 계산)

  • Seon-Hyung Kang
    • Journal of the Society of Naval Architects of Korea
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    • v.29 no.1
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    • pp.43-54
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    • 1992
  • A method of evaluating the velocity components induced by a Havelock source is presented in this paper. The mathematical manipulation of x, y and z-derivative of the Green function of the Havelock source by the use of contour integration on the complex plane has resulted in the expressions that can be readily incorporated with computer program. The accuracy and efficiency that can be secured by the use of the present mathematical expressions have been convincingly found to be highly satisfactory.

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