Resolved and subgrid dynamics of Rayleigh-Bénard convection
Resolved and subgrid dynamics of Rayleigh-Bénard convection
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瑞利-贝纳德对流的解析和亚网格动力学
DOI：
10.1017/jfm.2019.119
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发表时间：
2019
影响因子：
3.7
通讯作者：
Togni R
中科院分区：
文献类型：
--
作者：
Togni R
在这项工作中，我们提出并证明了研究热驱动湍流的理论框架的可靠性。它由二阶速度和温度结构函数及其极限情况的逐尺度预算方程组成，由湍流动能和温度方差预算表示。该框架代表了经典Kolmogorov和Yaglom方程的非均匀和各向异性流的扩展，并允许在流体域中的不同尺度和位置处发生的湍流过程的新评估。两个相关的特征尺度，或更大。这项研究表明，经典的涡粘性/扩散系数模型在大涡模拟可能会受到一些限制，大的过滤器长度，并应考虑替代封闭，以考虑在亚网格水平的非均匀过程。此外，基于滤波Kolmogorov和Yaglom方程的理论框架可能是未来评估亚网格尺度模型的一个有价值的工具。
In this work we present and demonstrate the reliability of a theoretical framework for the study of thermally driven turbulence. It consists of scale-by-scale budget equations for the second-order velocity and temperature structure functions and their limiting cases, represented by the turbulent kinetic energy and temperature variance budgets. This framework represents an extension of the classical Kolmogorov and Yaglom equations to inhomogeneous and anisotropic flows, and allows for a novel assessment of the turbulent processes occurring at different scales and locations in the fluid domain. Two relevant characteristic scales, or larger. This study suggests that classic eddy-viscosity/diffusivity models employed in large-eddy simulation may suffer from some limitations for large filter lengths, and that alternative closures should be considered to account for the inhomogeneous processes at subgrid level. Moreover, the theoretical framework based on the filtered Kolmogorov and Yaglom equations may represent a valuable tool for future assessments of the subgrid-scale models.