A comparative study of turbulent stratified shear layers: effect of density gradient distribution
A comparative study of turbulent stratified shear layers: effect of density gradient distribution
复制标题
湍流分层剪切层的比较研究：密度梯度分布的影响
DOI：
10.1007/s10652-022-09873-2
复制
发表时间：
2022
影响因子：
2.2
通讯作者：
Sarkar, Sutanu
中科院分区：
文献类型：
--
作者：
Pham, Hieu T.;Sarkar, Sutanu
通过直接数值模拟，比较了高雷诺数下不同密度梯度分布的湍流剪切层的演化。密度剖面包括均匀分层、双曲正切剖面和两层剖面的复合。所有剖面具有相同的初始体Richardson数（）;然而，最小梯度Richardson数和剪切层上的密度梯度分布在不同情况下不同。研究的目的是提供一个比较分析的剪切层的发展方面的剪切层的增长，湍流动能以及混合效率及其参数化。在所有情况下的剪切层的演变表明发展的开尔文-亥姆霍兹波涛，过渡到湍流的二次不稳定性，然后由湍流的衰减。通过比较发现，湍流混合量随剪切层内密度梯度分布而变化。最小梯度Richardson数和初始整体Richardson数与TKE产生、耗散和浮力通量的相关性不好。对于固定的混合效率，发现在两层密度分布的情况下是最高的，在均匀分层的情况下是最低的。然而，基于浮力雷诺数和Ozmidov和Ellison尺度比的通量系数的参数化在所有情况下都显示出相似的标度。
Direct numerical simulations are performed to compare the evolution of turbulent stratified shear layers with different density gradient profiles at a high Reynolds number. The density profiles include uniform stratification, two-layer hyperbolic tangent profile and a composite of these two profiles. All profiles have the same initial bulk Richardson number (); however, the minimum gradient Richardson number and the distribution of density gradient across the shear layer are varied among the cases. The objective of the study is to provide a comparative analysis of the evolution of the shear layers in term of shear layer growth, turbulent kinetic energy as well as the mixing efficiency and its parameterization. The evolution of the shear layers in all cases shows the development of Kelvin–Helmholtz billows, the transition to turbulence by secondary instabilities followed by the decay of turbulence. Comparison among the cases reveals that the amount of turbulent mixing varies with the density gradient distribution inside the shear layer. The minimum gradient Richardson number and the initial bulk Richardson number do not correlate well with the integrated TKE production, dissipation and buoyancy flux. The bulk mixing efficiency for fixedis found to be highest in the case with two-layer density profile and lowest in the case with uniform stratification. However, the parameterizations of the flux coefficient based on buoyancy Reynolds number and the ratio of Ozmidov and Ellison scales show similar scaling in all cases.
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DOI：
--
发表时间：
2014
期刊：
影响因子：
--
作者：
B. Mater;S. K. Venayagamoorthy
通讯作者：
S. K. Venayagamoorthy
DOI：
10.17863/cam.9670
发表时间：
2017
期刊：
--
影响因子：
--
作者：
Caulfield C
通讯作者：
Caulfield C
影响因子：
3.7
作者：
F. Jacobitz;S. Sarkar;C. W. Atta
通讯作者：
F. Jacobitz;S. Sarkar;C. W. Atta
分层湍流剪切流中的时间依赖性非单调混合：对浮力通量海洋学估计的影响
影响因子：
3.7
作者：
A. Mashayek;Colm‐cille P. Caulfield;W. Peltier
通讯作者：
W. Peltier
影响因子：
3.7
作者：
Lewin S
通讯作者：
Lewin S