Estimating Dependence of the Turbulent Length Scales on Model Resolution Based on A Priori Analysis
Estimating Dependence of the Turbulent Length Scales on Model Resolution Based on A Priori Analysis
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DOI：
10.1175/jas-d-14-0189.1
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发表时间：
2015-02
影响因子：
3.1
通讯作者：
Y. Kitamura
中科院分区：
文献类型：
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作者：
Y. Kitamura
雷诺平均Navier-Stokes模拟（RANS）和大涡模拟（LES）已被广泛用于大气边界层中不可分辨湍流运动的参数化。然而，有一个中间的模型分辨率，称为未知地带，其中RANS和LES都不合适。虽然确定一个适当的湍流长度尺度是必不可少的涡扩散率模型，它仍然是不确定的长度尺度之间的LES和RANS制度的过渡。在本研究中，依赖于湍流长度尺度的数值模式的水平分辨率的对流边界层的先验分析，探索适用于未知地区的湍流参数化方案进行了研究。本文提出了由湍动能耗散率和涡动粘性系数估算尺度的方法。估计的长度尺度取决于水平和垂直方向。
AbstractThe Reynolds-averaged Navier–Stokes simulation (RANS) and the large-eddy simulation (LES) have been widely used to parameterize unresolved turbulent motions for the atmospheric boundary layer. However, there is an intermediate model resolution, termed terra incognita, in which neither RANS nor LES is appropriate. Although identifying an appropriate turbulent length scale is essential for an eddy-diffusivity model, it is still uncertain how transition of the length scale is between the LES and RANS regimes. In the present study, dependence of the turbulent length scale on the horizontal resolution of a numerical model is investigated using a priori analysis for a convective boundary layer to explore a turbulent parameterization scheme applicable to the terra incognita region. Here, the approaches for estimating the length scales derived from the dissipation rate of the turbulent kinetic energy and the eddy viscosity are proposed. The estimated length scale depends on both the horizontal and vertica...