Probing high-Reynolds-number effects in numerical boundary layers
Probing high-Reynolds-number effects in numerical boundary layers
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DOI：
10.1063/1.4792164
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发表时间：
2013-02
影响因子：
4.6
通讯作者：
S. Pirozzoli;M. Bernardini
中科院分区：
文献类型：
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作者：
S. Pirozzoli;M. Bernardini
本文通过超大规模直接数值模拟（DNS）研究了低超声速区湍流边界层的高雷诺数行为。在DNS中首次获得雷诺数（Reτ=δ/δv = 4000，其中δ是边界层厚度，δv是粘性长度尺度），理论预测和实验表明，在该雷诺数下会出现与渐近雷诺数状态有关的现象。从与以前的DNS数据在较低的雷诺数的比较，我们发现的证据的一个持续的趋势朝着一个更强的印记的外层结构到近壁区域。这种效应在流动可视化和能谱中都清楚地表现出来。在平均速度剖面中观察到十多年的近对数变化，对数律常数k = 0.394，C = 4.84，并且趋势与实验相似。我们发现一些支持的证据存在争议的k-1区域的功率谱的流向速度fluctu…
We study the high-Reynolds-number behavior of a turbulent boundary layer in the low supersonic regime through very-large-scale direct numerical simulation (DNS). For the first time a Reynolds number is attained in DNS (Reτ=δ/δv≈4000, where δ is the boundary layer thickness and δv is the viscous length scale) at which theoretical predictions and experiments suggest the occurrence of phenomena pertaining to the asymptotic Reynolds number regime. From comparison with previous DNS data at lower Reynolds number we find evidence of a continuing trend toward a stronger imprint of the outer-layer structures onto the near-wall region. This effect is clearly manifested both in flow visualizations, and in energy spectra. More than a decade of nearly-logarithmic variation is observed in the mean velocity profiles, with log-law constants k ≈ 0.394, C ≈ 4.84, and a trend similar to experiments. We find some supporting evidence for the debated existence of a k−1 region in the power spectrum of streamwise velocity fluctu...