Local spectrum of commutation error in large eddy simulations
Local spectrum of commutation error in large eddy simulations
复制标题
大涡模拟中换向误差的局部谱
DOI：
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发表时间：
2004
期刊：
影响因子：
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通讯作者：
D. Goldstein
中科院分区：
文献类型：
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作者：
O. Vasilyev;D. Goldstein
在这篇简短的通信中，我们提出了一种新的数学工具，我们称之为局部谱分析，它可以用来获得关于大涡模拟中换向误差的局部谱含量的信息，以及它对滤光片形状和滤光片宽度不均匀的依赖关系。为了说明这些理论发现，对Reλ=168时强迫均匀湍流的2563直接数值模拟结果进行了局部对换谱分析。结果证实了换向误差的谱含量对滤波器形状的强烈依赖性：对于像高斯这样的光滑滤波器，谱是宽的，而对于接近尖锐截止的滤波器，谱含量是局部化的。此外，还证明了换向误差的幅度与滤波器宽度伸展因子成正比。
In this Brief Communication we present a new mathematical tool, which we call local spectrum analysis, that can be used to obtain information about local spectral content of the commutation error in large eddy simulations and its dependence on the filter shape and the non-uniformity of the filter width. To illustrate these theoretical findings, the local commutation spectrum analysis is applied to the results of 2563 direct numerical simulation of forced homogeneous turbulence at Reλ=168. The results confirm strong dependence of the spectral content of the commutation error on the filter shape: the spectrum is wide for smooth filters like Gaussian, while for filters, that are close to the sharp cut-off, the spectral content is localized. It is also demonstrated that the amplitude of the commutation error is linearly proportional to the filter width stretching factor.