• Title/Summary/Keyword: Splash

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Performance Evaluation of Molten Metal Splash Protective Fabrics (용융금속 방호보호복소재의 성능수준 평가)

  • Park, Pyoung-Kyu;Jin, Lu;Yoon, Kee-Jong
    • Korean Journal of Hazardous Materials
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    • v.6 no.2
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    • pp.55-61
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    • 2018
  • In this study, the molten metal protective performance of various molten metal protective clothing materials such as herringbone twill laminated aluminium foils, oxydized-polyacrylonitrile laminated with aluminium deposited polyethylene terephthalate films, twill fabric laminated with aluminium deposited polyethylene terephthalate films and nonwoven laminated with aluminum deposited polyethylene terephthalate films, were evaluated according to modified EN ISO 9185. The results showed that the molten metal protective performance of tested samples improved with the increase in fabric structure density, weight and thickness. In addition the effect of the thickness of aluminum foil on the molten metal protective performance is not significant. It was found the fabric is more important in the molten metal splash protective clothing.

A Study on the Characteristics of the Liquid Sheet Formed by a Splash Plate Nozzle at Low Jet Velocities (충돌벽 노즐의 저속 제트에 의한 액막 특성 연구)

  • H. U. Park;J. D. Kim;G. E. Song;B. S. Kang
    • Journal of ILASS-Korea
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    • v.29 no.2
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    • pp.75-82
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    • 2024
  • In this study, the thickness of the liquid sheet formed by a splash plate nozzle at low jet velocities was measured by the direct contact method. The spatial distribution characteristics of the sheet thickness in the radial and circumferential directions, and the effects of jet velocity and liquid viscosity were analyzed. The wavy surface was observed for low viscosity water, but not for high viscosity glycerol solutions. The sheet thickness decreased as the circumferential angle or the distance from the impinging point increased. The sheet thickness increased as the liquid viscosity increased. Comparison with the theoretical predictions for two impinging jets showed some differences from the measurement results.

Soil Detachment by Single and Multiple Waterdrops (우적(雨滴)에 의한 토양(土壤) 침식(侵蝕))

  • Miller, W.P.;Kim, Kye-Hoon
    • Applied Biological Chemistry
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    • v.38 no.2
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    • pp.151-156
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    • 1995
  • Single-drop splash/detachment studies and multiple-drop splash/detachment experiments were carried out to measure detachment by single and multiple drops. A raindrop tower 7.0 m in height was used to study soil splash by single drop raindrop impact over time on repacked soil samples in containers 76.2 mm in diameter. The waterdrop diameter and kinetic energy were 4.1 mm and $1.22{\times}10^{-3}$ J $drop^{-1}$, respectively. The samples consisted of five agricultural topsoils sieved to <2 mm, varying from sandy loam to clay loam in texture. The average weight of splashed soil particles after 75 drops did not show any significant difference between the five soils. The average weight of particles splashed by the first 15 drops showed that the sandy Pelham soil splashed to a greater degree than the others, and was therefore more detachable (p=0.05) than the other soils. The average weight of particles splashed by the last 15 drops also showed that the Pelham soil was the most detachable, with Cecil, Appling, Dyke, and Worsham soils being progressively less detachable. The effect of multiple drops on detachment was studied under a nozzle-type rainfall simulator at 74.9 mm $h^{-1}$ intensity for 85 min using the same soils as the single drop experiments. The total soil splash value for 85 min on Appling, Cecil, Dyke, Pelham, and Worsham soils were 6121, 6206, 4183, 5160, and 3247 g $m^{-2}$, respectively. There were no obvious relationships between soil loss measured from the different experiments.

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RADIAL FLOW AND DROPLETS SPLASH OBSERVED ON A WALL IMPINGEMENT JET (벽면 충돌분무의 반경방향 흐름과 액적 비산에 관한 고찰)

  • KIM, Young-Il
    • Journal of the Korean Society of Industry Convergence
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    • v.3 no.1
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    • pp.37-42
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    • 2000
  • 액체 분무가 벽면의 평평한 면에 충돌할 때의 거동에 대해 실험을 통하여 조사하였다. 각 분사노즐과 벽면까지의 거리 그리고 분사 속도에 있어서 충돌점에서의 액체 액막의 비산 거동과 평면에서의 액막의 흐름에 대하여 관찰하였다. 충돌점에서 비산하는 액적의 비산율을 정량적으로 측정하였다. 분사속도가 증가에 의해 충돌 거동은 5개의 영역으로 분류되며, 분사속도가 증가하면 비산율도 증가하게 된다. 또한, 충돌거리가 분무의 분열점보다 길때의 분사량의 약 반 정도가 비산하게 되는 결과가 얻어졌다.

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Effect of Welding Power Source on Splash in Spot Welding of Zinc Coated Steel (아연도금강판의 저항용접 시 날림발생에 미치는 용접전원의 영향)

  • 고미혜;이용기;이영배;조상명
    • Proceedings of the KWS Conference
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    • 2004.05a
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    • pp.63-65
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    • 2004
  • 아연도금강판은 일반 냉연강판에 비해 내식성과 내구섣이 우수하여 자동차, 토목, 건축, 가전산업 등 여러 분야에 널리 사용되고 있다. 그러나 저항용접 시 낮은 용점의 아연이 전극을 오염(Pick up)시켜 적정 용접전류가 높아지고 연속타점 시 저극의 오염으로 인해 날림(Splash)를 발생시켜 작업환경과 모재에 악영향을 주고있다. (중략)

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LES of Turbulent Mixing of Non-Reactive Flow in Gas Generator (가스발생기 비-반응 유동의 난류 혼합에 대한 LES 해석)

  • Lee, Chang-Jin
    • Journal of the Korean Society for Aeronautical & Space Sciences
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    • v.36 no.12
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    • pp.1171-1179
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    • 2008
  • LES analysis was conducted with in-house CFD code to investigate the turbulence evolution and interaction due to turbulence ring and splash plate in the gas generator. The calculation results show that the installation of turbulence ring can introduce additional turbulences and significantly improve turbulent mixing in the downstream flow. However, the addition of splash plate in the downstream of TR(Turbulence Ring) brings totally different shape of perturbation energy and enstrophy distribution into turbulent mixing. This enhancement can be done by the formation of the intensively strong vorticity and mixing behind the plate. Pressure drop was found to be a reasonable level of about 1% or less of initial pressure in all calculation cases. Also, calculation results revealed that the variation of shape and intrusion length of TR did not greatly affect the characteristics of turbulent mixing in the chamber. Even though the effect of installation location of splash plate on the turbulent mixing was not investigated yet, calculation results conclude the addition of splash plate leads to the increase in turbulent mixing with an acceptable pressure drop.

The Analysis of Chloride Penetration at Concrete and Repair Material under Tidal and Splash Zone (조간대와 비말대의 콘크리트와 보수재의 염분침투 특성분석)

  • Lee, Joon-Gu;Cho, Young-Kwoun;Kim, Meyong-Won;Kim, Kwan-Ho;Joo, Jae-Hong;Kim, Han-Joung
    • Proceedings of the Korea Concrete Institute Conference
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    • 2010.05a
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    • pp.207-208
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    • 2010
  • The building that supply tidal and splash zone was constructed near Seamangeum Gate Bridge. The specimens that will be tested for maintenance of gate bridge were exposed on the tidal and splash zone, totally about 650. The characteristics of strength, salt penetration profile, field application of surface repair material and section recover material will be acquired by periodical test. The program was developed to obtain optimal maintenance strategy of gate bridge as a marine concrete structure and to deposit experimental data, lab. test result, field test result, on its D/B. On this paper, the comparison of concrete and recover material in the salt penetration characteristics was expressed. The quantitative analysis of salt contents in concrete surface was most important so the improvement for the machine of gathering power of concrete and the apparatus of measuring chloride contents was proceeded at this time. The two conclusions were summarized like as - The resistance of chloride attack of concrete was appeared 2.5 times bigger than that of recover material - The resistance of chloride attack of polymer series was appeared more higher than that of others.

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Experiments Research for Steel Corrosion of Reinforced Concrete Specimens in the Splash Zone (비말대 거치 철근콘크리트 시험체의 철근부식에 관한 연구)

  • 이상국;류금성;정영수;유환구;김국한
    • Proceedings of the Korea Concrete Institute Conference
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    • 1999.10a
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    • pp.755-758
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    • 1999
  • Reinforced concrete is in general known as high durability construction material under normal environments due to strong alkalinity of cement. Marine and harbour concrete in the tidal and the splash zone at seashore are exposed to cyclic wet and dry saltwaters which cause to accelerate corrosion of reinforcing steel in concrete. If corrosion resistance of concrete gets to weaken due to carbonations and cracks in cover concrete, furthermore, concrete durability rapidly decreases by corrosion of reinforcement steel embedded in concrete. The objective of this study is to develop appropriate corrosion protection systems so as to enhance the durability of concrete by controlling the cover depth of concrete and by using corrosion inhibitors as concrete admixtures.

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Numerical Simulation of Multiphase Flows with Material Interface due to Density Difference by Interface Capturing Method (경계면 포착법에 의한 밀도차이에 따른 물질경계면을 갖는 다상유동 수치해석)

  • Myon, Hyon-Kook
    • Transactions of the Korean Society of Mechanical Engineers B
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    • v.33 no.6
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    • pp.443-453
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    • 2009
  • The Rayleigh-Taylor instability, the bubble rising in both partially and fully filled containers and the droplet splash are simulated by an in-house solution code(PowerCFD), which are typical benchmark problems among multiphase flows with material interface due to density difference. The present method(code) employs an unstructured cell-centered method based on a conservative pressure-based finite-volume method with interface capturing method(CICSAM) in a volume of fluid(VOF) scheme for phase interface capturing. The present results are compared with other numerical solutions found in the literature. It is found that the present method simulates efficiently and accurately complex free surface flows such as multiphase flows with material interface due to both density difference and instability.

The Characteristics of Strength of Concrete Specimens under Tidal Environment (해양환경에 폭로된 콘크리트 실험체의 역학적 특성)

  • Lee, Joon-Gu;Kim, Meyong-Won;Kim, Kwan-Ho;Joo, Jae-Hong;Kim, Han-Joung
    • Proceedings of the Korea Concrete Institute Conference
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    • 2009.05a
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    • pp.277-278
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    • 2009
  • The building that supply tidal and splash zone was constructed near Seamangeum Gate Bridge. The specimens that will be tested for maintenance of gate bridge were exposed on the tidal and splash zone, totally about 650(Fig. 1). The characteristics of strength, salt penetration profile, field application of surface repair material and section recover material will be acquired by periodical test. The program was developed to obtain optimal maintenance strategy of gate bridge as a marine concrete structure and to deposit experimental data, lab. test result, field test result, on its D/B. On this paper, we hope to introduce two years exposure data as compressive strength, the modulus of elasticity, the modulus of dynamic elasticity, field adoption of repair and recover materials. As briefly speaking the results, possion's ratio, elasticity, strength was general, but the recover materials have some problems. There was crack between concrete and recover material and delamination figures.

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