• Title/Summary/Keyword: Viscous finger

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CHARACTERISTICS OF INTERFACE BETWEEN TWO-PHASE FLUIDS FLOW IN A FURNACE WITH POROUS MEDIUM (다공성 매질이 존재하는 용광로 내부 이상유체 경계면의 특성)

  • Park, G.M.;Lee, D.J.;Lee, J.H.;Yoon, H.S.
    • Journal of computational fluids engineering
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    • v.21 no.1
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    • pp.110-116
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    • 2016
  • The present study numerically investigated the deformation of the interface of two-phase fluids flow in a blast furnace. To simulate three-dimensional(3D) incompressible viscous two-phase flow in the furnace filled with the air and molten iron, the volume of fluid(VOF) method based on the finite volume method has been utilized. In addition, the porous medium with the porosity has been considered as the bed of the particles such as cokes and char etc. For the comparison, the single phase flow and the two-phase flow without the porosity have been simulated. The two-phase flow without porosity condition revealed the smooth parabolic profile of the free surface near the outlet. However, the free surface under the porosity condition formed the viscous finger when the free surface was close to the outlet. This viscous finger accelerated the velocity of the free surface falling and the outflow velocity of the fluids near the outlet.

Micro-structural Evolutions of Polyimide Composite Films with Graphenes (그라핀을 포함하는 폴리이미드 멤브레인의 미세조직구조 변화)

  • Shim, Seong Eun;Kim, Jungsoo;Nam, Dae-Geun;Oh, Weontea
    • Journal of the Korean Institute of Electrical and Electronic Material Engineers
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    • v.27 no.1
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    • pp.56-60
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    • 2014
  • The polyimide composite membranes were prepared with polyimide composite solutions including graphenes by using the phase inversion method. The morphologies of these membranes were significantly changed according to the graphene loadings in composite solutions and the solvent systems of the composite solutions. The finger-like macro-voids were formed in the hollow fiber membranes which were prepared in the NMP solvent system with a small amount of ethanol. As increasing the content of the viscous alcohols such as glycerol or 1,3-propanediol in the composite solution, however, the morphologies of the hollow fiber membranes were changed to sponge-like types. In case of flat membranes, the increase of graphene content in polyimide composites causes that their membranes change from the finger-like macro-porous to sponge-like morphologies.