Multifractal subgrid-scale modeling for large-eddy simulation. I. Model development and a priori testing
Multifractal subgrid-scale modeling for large-eddy simulation. I. Model development and a priori testing
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DOI：
10.1063/1.1965058
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发表时间：
2005-07
影响因子：
4.6
通讯作者：
G. Burton;W. Dahm
中科院分区：
文献类型：
--
作者：
G. Burton;W. Dahm
给出了一种在湍流大涡模拟中模拟亚网格尺度应力的新方法，该方法基于从亚网格涡量场的多重分形表示中显式地估计亚网格速度分量。该方法是基于已有研究表明，在高雷诺数湍流中，拟合场在惯性范围尺度上表现出多重分形标度相似性。因此，尺度不变的乘性级联给出了每个可分辨尺度单元内的子格子涡量的空间分布，而加性级联给出了从可分辨尺度Δ到粘性尺度λν的子格子涡度取向的递进各向同性去相关。然后，从亚格子涡量场上的Biot-Savart积分得到亚格子速度。得到的子网格速度分量变成了解析标度量的简单代数表达式，然后允许显式计算子网格应力τij*。太.。
Results are presented from a new approach to modeling the subgrid-scale stresses in large-eddy simulation of turbulent flows, based on explicit evaluation of the subgrid velocity components from a multifractal representation of the subgrid vorticity field. The approach is motivated by prior studies showing that the enstrophy field exhibits multifractal scale-similarity on inertial-range scales in high Reynolds number turbulence. A scale-invariant multiplicative cascade thus gives the spatial distribution of subgrid vorticity magnitudes within each resolved-scale cell, and an additive cascade gives the progressively isotropic decorrelation of subgrid vorticity orientations from the resolved scale Δ to the viscous scale λν. The subgrid velocities are then obtained from Biot–Savart integrals over this subgrid vorticity field. The resulting subgrid velocity components become simple algebraic expressions in terms of resolved-scale quantities, which then allow explicit evaluation of the subgrid stresses τij*. T...