• Title/Summary/Keyword: Morton Number

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Two-dimensional Numerical Simulation of the Rising Bubble Flows Using the Two Phase Lattice Boltzmann Method (2상 격자 볼츠만 방법을 이용한 상승하는 기포 유동 2차원 수치 모사)

  • Ryu, Seung-Yeob;Park, Cheon-Tae;Han, Seung-Yeul;Ko, Sung-Ho
    • The KSFM Journal of Fluid Machinery
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    • v.13 no.4
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    • pp.31-36
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    • 2010
  • Free energy based lattice Boltzmann method (LBM) has been used to simulate the rising bubble flows with large density ratio. LBM with compact discretization is able to reduce the spurious current of the static bubble test and be satisfied with the Laplace law. The terminal rise velocity and shape of the bubbles are dependent on Eotvos number, Morton number and Reynolds number. For single bubble flows, simulations are executed for various Eotvos number, Morton number and Reynolds number, and the results are agreed well with the experiments. For multiple bubbles, the bubble flow characteristics are related by the vortex pattern of the leading bubble. The coalescence of the bubbles are simulated successfully and the subsequent results are presented. The present method is validated for static, dynamic bubble test cases and compared to the numerical, experimental results.

Diagnosis of Morton's Neuroma Using MR Imaging scans (지간 신경종의 자기 공명 영상을 이용한 진단)

  • Hong, Ki-Do;Ha, Sung-Sik;Sim, Jae-Cheon;Kim, Jae-Young
    • Journal of Korean Foot and Ankle Society
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    • v.7 no.1
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    • pp.131-134
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    • 2003
  • Most interdigital neuroma can be diagnosed clinically. But, diagnostic local injection method, sonography and magnetic resonance image(MRI) have been used as secondary tests for clinical confirmation or surgery. Recently, there have been active discussions on the method of interdigital neuroma diagnosis for which sonography or MRI is used. For finding out the location or the number of interdigital neuroma particularly in non-typical clinical manifestation or surgery, MRIs, which are exellent in tissue contrast, may be quite helpful. This case had an interdigital neuroma showing non-typical manifestation. MRIs were used for clinical diagnostic confirmation and finding out the location and the number of interdigital neuroma. Thus, the validity along with literary consideration is being reported.

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Basic Analysis of Bubble Behavior in the Viscous Flow Domain with the Free Interface (자유표면을 가지는 점성 유동장내의 기포거동에 관한 기초해석)

  • I.R. Park;H.H. Chun
    • Journal of the Society of Naval Architects of Korea
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    • v.39 no.1
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    • pp.16-27
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    • 2002
  • A level-set method is used for analyzing the behaviors of gas bubbles in two fluids incompressible viscous flow domain. The governing equations are solved by using a finite volume method. The numerical results are verified by comparing with the experimental and other computational results. Computations for the deformations and motions of one or multi-bubbles in the flow domain with the initial undisturbed free interface are conducted. It can be seen that numerical results for different surface tension and density ratio arise very different behaviors of bubbles. When bubbles rise near the free interface, the free interface gives some great influence on the behaviors of bubbles. The present results computed by a level-set method give useful information about the properties of bubble motions and deformations.