A new formulation for the streamwise turbulence intensity distribution
A new formulation for the streamwise turbulence intensity distribution
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流向湍流强度分布的新公式
DOI：
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发表时间：
2011
期刊：
影响因子：
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通讯作者：
A. Segalini
中科院分区：
文献类型：
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作者：
P. Alfredsson;R. Örlü;A. Segalini
本文用Alfredsson和Örlü [Eur. J. Fluid Mech. B/Fluids，42，403（2010）]。在诊断图中，局部湍流强度显示为用参考速度标度归一化的局部平均速度的函数。在边界层的外部区域中，观察到与雷诺数无关的湍流强度的普遍线性衰减。从这个线性区域的偏差出现在缓冲区，似乎是普遍的，当与摩擦速度归一化。因此，提出了一种新的流向速度湍流强度分布的经验拟合，并将结果与最新可靠的高雷诺数实验进行比较，并外推到与大气边界层相关的雷诺数。
Numerical and experimental data from zero pressure-gradient turbulent boundary layers over smooth walls have been analyzed by means of the so called diagnostic plot introduced by Alfredsson & Örlü [Eur. J. Fluid Mech. B/Fluids, 42, 403 (2010)]. In the diagnostic plot the local turbulence intensity is shown as a function of the local mean velocity normalized with a reference velocity scale. In the outer region of the boundary layer a universal linear decay of the turbulence intensity is observed independent of Reynolds number. The deviation from this linear region appears in the buffer region and seems to be universal when normalized with the friction velocity. Therefore, a new empirical fit for the streamwise velocity turbulence intensity distribution is proposed and the results are compared with up to date reliable high-Reynolds number experiments and extrapolated towards Reynolds numbers relevant to atmospherical boundary layers.