• 제목/요약/키워드: Contractive and dilative motion

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A Numerical Simulation for Contractive and Dilative Periodic Motion on Axisymmetric Body

  • Kim, Moon-Chan
    • Journal of Ship and Ocean Technology
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    • 제3권1호
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    • pp.1-11
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    • 1999
  • Numerical simulation for the axisymmetric body with contractive and dilative periodic motion is carried out. The present analysis shows that a propulsive force can be obtained in highly viscous fluid by the contractive and dilative motion of axisymmetric body. An axisymmetric code is developed with unstructured grid system for the simulation of complicated motion and geometry. It is validated by comparing with the results of Stokes approximation with the problem of uniform flow past a sphere in low Reynolds number($R_n$ = 1). The validated code is applied to the simulation of contractive and dilative periodic motion of body whose results are quantitatively compared with the two dimensional case. The simulation is extended to the analysis of waving surface with projecting part for finding out the difference of hydrodynamics performance according to variation of waving surface configuration. The present study will be the basic research for the development of the propulsor of an axisymmetric micro-hydro-machine.

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수축팽창 운동에 의한 축대칭 마이크로-하이드로-머신의 추진을 위한 수치 시뮬레이션 (A Numerical Simulation for the Propulsion of Axisymmetric Micro-Hydro-Machine by Contractive and Dilative Motion)

  • 김문찬
    • 한국전산유체공학회:학술대회논문집
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    • 한국전산유체공학회 2001년도 춘계 학술대회논문집
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    • pp.30-37
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    • 2001
  • A Numerical simulation for the propulsion of axisymmetric body by contractive and dilative motion is carried out. The present analysis shows that a propulsive force can be obtained in highly viscous fluid by a contractive and dilative motion of axisymmetric body. An axisymmetric analysis code is developed with unstructured grid system for the simulation of complicated motion and geometry. The developed code is validated by comparing with the results of stokes approximation with the problem of uniform flow past a sphere in low Reynolds number($R_n=1$). The validated code is applied to the simulation of contractive and dilative motion of body. The simulation is extended to the analysis of waving surface with projecting part for finding out the difference of hydrodynamic performance according to the variation of waving surface configuration. The present study will be the basic research for the development of the propulsor of an axisymmetric micro-hydro-machine.

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셀중심법에 의한 축대칭 극소 로봇의 압축팽창운동에 대한 수치적인 연구 (A Numerical Simulation based on Cell-centered Scheme for Contractive and Dilative Motion on Axisymmetric Micro-hydro machine)

  • 강효길;김문찬;전호환
    • 대한조선학회논문집
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    • 제41권2호
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    • pp.90-97
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    • 2004
  • Flow mechanism of contractive and dilative motion is numerically investigated to obtain a propulsive force in highly viscous fluid. An axisymmetric code is developed with unstructured grid system based on cell-centered scheme. It is validated by comparing with the results of Stokes approximation for the problem of uniform flow past a sphere in low Reynolds number(R$_{n}$=1). The validated code is applied to the simulation of contractive and dilative periodic motion of body whose results are quantitatively compared with the two dimensional case. In order to investigate the grid dependency, two different grids are applied to the present computations. The present study provides key information for the development of an axisymmetric Micro-hydro-robot.t.

비정규 격자를 이용한 극소 로봇의 추진 해석 (Simulation for the Propulsion of Micro-Hydro-Machine with Unstructured Grid)

  • 김문찬;하동대
    • 대한조선학회논문집
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    • 제39권3호
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    • pp.1-7
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    • 2002
  • 검증된 프로그램을 통하여 수축 팽창 운동에 대한 해석을 수행하였으며, 해석 결과 레이놀즈수가 작아지게($R_n{\fallingdotseq}1$) 되면 점성력을 이용한 추진이 효과적일 것으로 나타났고, 계산 결과를 꼭지점법과 비교하였다. 본 연구를 통하여 극도로 점성이 큰 지역에서 통상의 추진기로 추진이 불가능한 곳에서도 추진할 수 있는 새로운 추진 시스템을 제안하였으며, 이 시스템은 micro-hydro-machine의 추진 장치로 활용될 수 있으리라 기대된다.