• 제목/요약/키워드: Circulatory Oscillation

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회전요동하는 원통내의 유동특성 - 이론적 해석 (Fluid Flow in a Circular Cylinder Subject to Circulatory Oscillation-Theoretical Analysis)

  • 서용권;김현민
    • 대한기계학회논문집B
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    • 제20권12호
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    • pp.3960-3969
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    • 1996
  • A fluid flow inside a circular cylinder subject to horizontal and circular oscillation is analyzed theoretically. Under the assumption of small-amplitude oscillation, the governing equations take linear forms. The velocity field is obtained in terms of the first kind of Bessel function of order 1. It was found that a particle describes an orbit close to a circle in the central region and an arc near the side wall. We also obtained the Stokes' drift velocity induced by the traveling wave along the circumferential direction. The Eulerian streaming velocities at the edge of the bottom and side boundary layers were also obtained. It was shown that the vertical component of the steady streaming velocity on the side wall is almost proportional to the amplitude of the free surface motion.

회전요동하는 원통내의 유동 및 교반특성을 위한 수치해석적 연구 (Numerical Study on Fluid Flows and Stirring in a Circular Cylinder Subjected to Circulatory Oscillation)

  • 김현민;서용권
    • 대한기계학회논문집B
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    • 제23권3호
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    • pp.408-418
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    • 1999
  • Incompressible flow inside a circular cylinder Including periodically oscillating free surface waves was studied primarily by using a numerical method. We developed a finite difference scheme based on the MAC method applicable to three-dimensional free-surface flows, and applied it to the present flow model to study tho flow characteristics as well as the fluid stirring. To verify the validity of our scheme, we performed a simple experiment for flow visualization. We found that the numerical results show a reasonable agreement with the observed flow patterns.

회전요동하는 원통내의 유동특성 - 수치해석 및 실험 (Fluid Flow in a Circular Cylinder Subject to Circulatory Oscillation-Numerical Analysis and Experiment)

  • 서용권;박준관
    • 대한기계학회논문집B
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    • 제20권12호
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    • pp.3970-3979
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    • 1996
  • A fluid flow inside a circular cylinder subject to horizontal, circular oscillation is analyzed numerically and experimentally. The steady streaming velocities at the edges of the boundary layers on the bottom and side surfaces of the cylinder obtained in the previous paper are used as the boundary conditions in the governing equations for the steady flow motion in the interior region. The Stokes' drift velocity obtained in the previous paper also constitutes the Lagrangian velocity which is used in the momentum equations. It turns out that the interior steady flow is composed of one cell, ascending at the center and descending near the side surface, at the streaming Reynolds number 2500. However, at the streaming Reynolds number 25, the flow field is divided into two cells resulting in a descending flow at the center. The experimentally visualized flow patterns at the bottom surface agree well with the analytical solutions. The visualization experiment also confirms the flow direction as well as the center position of the cell obtained by the numerical solutions.