A unifying framework for parameterizing stably stratified shear-flow turbulence
A unifying framework for parameterizing stably stratified shear-flow turbulence
复制标题
参数化稳定分层剪切流湍流的统一框架
DOI：
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发表时间：
2014
期刊：
影响因子：
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通讯作者：
S. K. Venayagamoorthy
中科院分区：
文献类型：
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作者：
B. Mater;S. K. Venayagamoorthy
提出了一种稳定分层剪切流湍流参数化的替代框架。使用量纲分析，四个无量纲参数的兴趣被确定，考虑分层，剪切，粘度和标量扩散的独立影响。在地球物理应用的利益，该问题进一步简化，只考虑高雷诺数流。这导致基于浮力强度参数的二维参数空间（即，弗劳德数的倒数）和剪切强度参数。考虑梯度Richardson数，可以将空间划分为非强迫制度，剪切为主的制度，和浮力为主的制度。在此基础上，一个大的数据库的直接数值模拟和实验室数据从各种来源进行评估。特别令人感兴趣的是观察到的倾覆长度尺度。发现在浮力主导的区域中，翻转与k1/2/N成比例，在剪切主导的区域中，翻转与k1/2/S成比例.
An alternative framework for parameterizing stably stratified shear-flow turbulence is presented. Using dimensional analysis, four non-dimensional parameters of interest are identified that consider the independent effects of stratification, shear, viscosity, and scalar diffusivity. In the interest of geophysical applications, the problem is further simplified by considering only high Reynolds number flow. This leads to a two-dimensional parameter space based on a buoyancy strength parameter (i.e., an inverse Froude number) and a shear strength parameter. Consideration for the gradient Richardson number allows the space to be divided into an unforced regime, a shear-dominated regime, and a buoyancy-dominated regime. On this basis, a large database of direct numerical simulation and laboratory data from various sources is evaluated. Of particular interest is the observed length scale of overturning. Overturns are found to scale with k1/2/N in the buoyancy-dominated regime, k1/2/S in the shear-dominated reg...