## 抄録

The triple velocity, the pressure-velocity, and the scalar-scalar-velocity correlations in incompressible turbulent shear flows and in passive scalar fields are studied by using the two-scale direct-interaction approximation, which satisfies the solenoidal condition of the velocity fields and systematically introduces the cutoff wave numbers. As a result, we obtain their expressions of the gradient diffusion type involving the effect of cross-diffusion. The model constants in the obtained expressions for the triple velocity and the pressure - velocity correlations are close to the values used in the turbulence models. The derived expression for the scalar-scalar-velocity correlation shows the complex dependence on the ratio R of the velocity length scale to the scalar one. As a special case of R= 1, we obtain its explicit expression whose model constant also agrees well with the numerically optimized value.

本文言語 | English |
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ページ（範囲） | 2636-2646 |

ページ数 | 11 |

ジャーナル | Physics of Fluids |

巻 | 10 |

号 | 10 |

DOI | |

出版ステータス | Published - 1998 |

## 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