## 抄録

The subgrid-scale (SGS) models based on the coherent structure in grid-scale flow fields are proposed and are applied to (non-)rotating homogeneous turbulences and turbulent channel flows. The eddy viscosity is modeled by a coherent structure function (CSF) with a fixed model-parameter. The CSF is defined as the second invariant normalized by the magnitude of a velocity gradient tensor and plays a role of wall damping. The probability density function of the CSF is non-Gaussian showing an intermittency effect. The model parameter is locally determined, and it is always positive and has a small variance. These models satisfy a correct asymptotic behavior to a wall for incompressible flows. It is shown that the SGS models with an energy-decay suppression function which indicates also a pseudo-backscatter are consistent with the asymptotic material frame indifference in a rotating frame. Since the CSF characterizing turbulent flows has relation to the SGS energy dissipation, the present SGS models are applicable not only to (non-)rotating homogeneous and shear turbulences but also to laminar flows. The proposed models have almost the same performance as the dynamic Smagorinsky model for (non-)rotating homogeneous turbulences and turbulent channel flows, but these models do not need to average or clip the model parameter, use an explicit wall-damping function, or change the fixed-parameter, so that they are suitable for engineering applications of large-eddy simulation.

本文言語 | English |
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論文番号 | 045104 |

ページ（範囲） | 045104-1-045104-12 |

ジャーナル | Physics of Fluids |

巻 | 17 |

号 | 4 |

DOI | |

出版ステータス | Published - 2005 4月 |

## ASJC Scopus subject areas

- 計算力学
- 凝縮系物理学
- 材料力学
- 機械工学
- 流体および伝熱