Development of a new dynamic procedure for the Clark model of the subgrid-scale scalar flux using the concept of optimal estimator
Development of a new dynamic procedure for the Clark model of the subgrid-scale scalar flux using the concept of optimal estimator
复制标题
使用最优估计器的概念为亚网格尺度标量通量的 Clark 模型开发新的动态程序
DOI：
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发表时间：
2011
期刊：
影响因子：
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通讯作者：
G. Balarac
中科院分区：
文献类型：
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作者：
Y. Fabre;G. Balarac
湍流平流标量的准确预测是各种应用所必需的。在大涡模拟的框架下，必须采用精确的亚网格尺度标量通量模型。在这项工作中，各种动态SGS模型的性能首先通过最优估计量的概念进行先验测试进行评估。在5123个网格点上对均匀各向同性湍流进行了直接数值模拟。过滤后的量是使用盒子或光谱截止滤波器从DNS数据中提取的。然后根据结构和功能性能评估模型的准确性，即，该模型的能力，以本地近似SGS未知项和再现其充满活力的行动，分别。结果表明，克拉克模型具有最佳的参数来描述SGS标量通量。然而，经典的动力学过程通常用于计算模型系数导致较大的误差。一个新的动态过程是t...
Accurate prediction of a scalar advected by a turbulent flow is needed for various applications. In the framework of large-eddy simulation (LES), an accurate subgrid-scale (SGS) model for the subgrid-scale scalar flux has to be used. In this work, the performance of various dynamic SGS models is first evaluated by a priori tests through the concept of optimal estimator. Direct numerical simulation (DNS) in homogeneous isotropic turbulence is performed on 5123 grid points. Filtered quantities are extracted from the DNS data using a box or a spectral cut-off filter. The models’ accuracy is then evaluated in term of structural and functional performances, i.e., the model capacity to locally approximate the SGS unknown term and to reproduce its energetic action, respectively. It is shown that the Clark model has the best set of parameters to describe the SGS scalar flux. However, the classic dynamic procedure usually applied to compute the model coefficient leads to a large error. A new dynamic procedure is t...