Effects of finite spatial and temporal resolution in direct numerical simulations of incompressible isotropic turbulence
Effects of finite spatial and temporal resolution in direct numerical simulations of incompressible isotropic turbulence
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不可压缩各向同性湍流直接数值模拟中有限空间和时间分辨率的影响
DOI：
10.1103/physrevfluids.3.064603
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发表时间：
2018
影响因子：
2.7
通讯作者：
Pope, S. B.
中科院分区：
文献类型：
--
作者：
Yeung, P. K.;Sreenivasan, K. R.;Pope, S. B.
随着计算能力的增长以及雷诺数不断增加的湍流正通过直接数值模拟进行计算，关于足够的空间和时间分辨率的传统假设正不断受到挑战。我们进行了系统的研究，通过数值模拟在不同的空间和时间分辨率的分辨率的影响，以澄清适当的缩放耗散和涡度拟能（涡度平方）。结果表明，在空间和/或时间分辨率不足导致高估的可能性和强度的极端波动的耗散和拟能。例如，为了准确地捕捉罕见事件，人们不仅需要随着雷诺数的增加而越来越小的柯尔莫哥洛夫尺度分数的网格分辨率，而且还需要比先前假设的足够小的柯朗数。从另一种方法，在波数空间截断更严格的标准，允许混叠误差被完全删除的结果进行了一些比较。与以前的工作相比，目前的数据不支持耗散和涡度拟能概率密度函数（PDF）在高雷诺数下在远尾彼此接近的概念。然而，这两个PDF格式是非常相似的形式，被很好地描述了拉伸指数。
As computing power has grown and turbulent flows at increasing Reynolds numbers are being computed by direct numerical simulations, conventional assumptions on adequate spatial and temporal resolutions are being continually challenged. We perform a systematic study of the resolution effects via numerical simulations at various spatial and temporal resolutions to clarify the proper scaling of dissipation and enstrophy (vorticity squared). Results show that inadequate resolution in space and/or time leads to overestimation of the likelihood and intensity of extreme fluctuations in dissipation and enstrophy. In order to capture rare events accurately, for instance, one needs to have not only grid resolutions that are increasingly smaller fractions of the Kolmogorov scale as the Reynolds number increases but also the Courant number that becomes increasingly smaller than that assumed to be adequate previously. Some comparisons are made with results obtained from an alternative approach where a stricter criterion for truncation in wave-number space allows aliasing errors to be removed completely. In contrast to prior work, the present data do not support the notion that dissipation and enstrophy probability density functions (PDFs) approach each other in the far tails at high Reynolds number. However the two PDFs are remarkably similar in form, being well described by stretched exponentials.
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影响因子：
3.7
作者：
Yeung, P. K.;Donzis, D. A.;Sreenivasan, K. R.
通讯作者：
Sreenivasan, K. R.
湍流/非湍流界面附近的耗散率
DOI：
--
发表时间：
2019
期刊：
影响因子：
--
作者：
K. Nagata;T. Watanabe;C. B. da Silva
通讯作者：
C. B. da Silva
DOI：
--
发表时间：
2013
期刊：
影响因子：
--
作者：
J. Luévano
通讯作者：
J. Luévano
影响因子：
3.7
作者：
Ishihara, T.;Kaneda, Y.;Uno, A.
通讯作者：
Uno, A.
影响因子：
4.6
作者：
Nelkin, M
通讯作者：
Nelkin, M