• Title/Summary/Keyword: 예면경계법

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Numerical Simulation of Dendritic Growth of the Multiple Seeds with Fluid Flow (유체 유동을 동반한 다핵 수치상결정의 미세구조성장에 대한 수치해석적 연구)

  • Yoon, Ik-Roh;Shin, Seung-Won
    • Transactions of the Korean Society of Mechanical Engineers B
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    • v.33 no.7
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    • pp.469-476
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    • 2009
  • Most material of engineering interest undergoes solidification process from liquid state. Identifying the underlying mechanism during solidification process is essential to determine the microstructure of material thus the physical properties of final product. In this paper, effect of fluid convection on the dendrite solidification morphology is studied using Level Contour Reconstruction Method. Sharp interface technique is used to implement correct boundary condition for moving solid interface. The results showed good agreement with exact boundary integral solution and compared well with other numerical techniques. Effects of Peclet number and undercooling on growth of dendrite tip of both single and multiple seeds have been also investigated.

Direct-current Dielectrophoretic Motions of a Single Particle due to Interactions with a Nearby Nonconducting Wall (비전도성 벽과의 상호작용에 따른 단일 입자의 직류 유전영동 운동)

  • Kang, Sangmo
    • Transactions of the Korean Society of Mechanical Engineers B
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    • v.39 no.5
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    • pp.425-433
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    • 2015
  • In this paper, we have numerically investigated two-dimensional dielectrophoretic (DEP) motions of a single particle suspended freely in a viscous fluid, interacting with a nearby nonconducting planar wall, under an externally applied uniform direct-current electric field. Particularly, we solve the Maxwell equation with a large sharp jump in the electric conductivity at the particle-fluid interface and then integrate the Maxwell stress tensor to compute the DEP force on the particle. Results show that, under an electric field parallel to the wall, one particle is always repelled to move far away from the wall and the motion depends strongly on the particle-wall spacing and the particle conductivity. The motion strength vanishes when the particle is as conductive as the fluid and increases as the conductivity deviates further from that of the fluid.