• Title/Summary/Keyword: 외재적 필터링

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DEVELOPMENT OF A LARGE EDDY SIMULATION METHOD ON UNSTRUCTURED MESHES (비정렬 격자를 이용한 LES 기법 개발)

  • Lee, K.S.;Baek, J.H.
    • 한국전산유체공학회:학술대회논문집
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    • 2006.10a
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    • pp.106-109
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    • 2006
  • A large eddy simulation with explicit filters on unstructured mesh is presented. Two explicit filters are adopted for reducing the aliasing error of the nonlinear convective term and measuring the level of subgrid scale velocity fluctuation, respectively. The developed subgrid scale model is basically eddy viscosity model which depends on the explicitly filtered fields and needs no additional ad hoc wall treatment such as van Driest damping function. As a validation problem, the flows around a sphere at several Reynolds numbers, including laminar and turbulent regimes, are calculated and compared to experimental data and numerical results in the literature.

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A Subgrid scale model with a 3 -dimensional explicit filtering (3차원 외재적 필터링 을 이용한 SGS 모델)

  • Lee, Kyung-Seh;Baek, Je-Hyun
    • 한국전산유체공학회:학술대회논문집
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    • 2008.03b
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    • pp.634-637
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    • 2008
  • A large eddy simulation with an explicit filter on unstructured mesh is presented. The flow filed is semi-implicitly marched by a fractional step method. Spatial discretization of the solver is designed to guarantee the second order accuracy. An isotropic explicit filter is adopted for measuring the level of subgrid scale velocity fluctuation. The filter is linearity-preserving and has second order commutation error. The developed subgrid scale model is basically eddy viscosity model which depends on the explicitly filtered fields and needs no additional ad hoc wall treatment, such as van Driest damping function. For the validation, the flows in a channel and a pipe are calculated and compared to experimental data and numerical results in the literature.

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LARGE EDDY SIMULATION OF THE FLOW AROUND A SPHERE WITH UNSTRUCTURED MESH (비정렬 격자를 이용한 구 주위의 큰에디 모사)

  • Lee, K.S.;Baek, J.H.
    • 한국전산유체공학회:학술대회논문집
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    • 2007.04a
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    • pp.41-44
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    • 2007
  • A large eddy simulation method with unstructured mesh is presented. Two explicit filtering procedures are adopted for reducing the aliasing error of the nonlinear convective term and measuring the level of subgrid scale velocity fluctuation, respectively. The developed subgrid scale model is basically an eddy viscosity model which depends on both local velocity fluctuation level and local grid scale. As a validation problem, the flows around a sphere of several Reynolds numbers are simulated and some characteristic quantities are compared to experimental data and numerical results in the literature.

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