A priori and a posteriori tests of inflow conditions for large-eddy simulation
A priori and a posteriori tests of inflow conditions for large-eddy simulation
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DOI：
10.1063/1.1811672
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发表时间：
2004-12-01
影响因子：
4.6
通讯作者：
Kaltenbach, HJ
中科院分区：
文献类型：
--
作者：
Keating, A;Piomelli, U;Kaltenbach, HJ
对湍流壁面边界大涡模拟的入流条件进行了比较。与前人的研究结果一致，发现入流速度的频谱含量是重要的。基于随机噪声或仅基于小尺度涡旋的流入条件很快就会消散。对单独计算得到的时间序列进行时间和空间滤波表明，捕捉等于或大于流动整体长度尺度的维度的涡旋是很重要的。在空间发展的槽道湍流模拟中，测试了三种生成来流速度场的方法。引入真实长度尺度的合成湍流生成方法比不相关的随机噪声更适合，但在建立真实湍流之前，仍需要相当长的发展长度。在不同的流动条件下，一种基于单独计算获得的湍流数据的循环方法被发现导致更快的转变。一种包括控制回路的强迫方法似乎也是有效的，它在不到十个通道半高的范围内产生具有正确雷诺应力和关联性的湍流。(C)美国物理研究所。
Comparisons of inflow conditions for large-eddy simulations of turbulent, wall-bounded flows are carried out. Consistent with previous investigations, it is found that the spectral content of the inflow velocity is important. Inflow conditions based on random-noise, or small-scale eddies only, dissipate quickly. Temporal and spatial filtering of a time series obtained from a separate calculation indicates that it is important to capture eddies of dimensions equal to or larger than the integral length scale of the flow. Three methods for generating inflow velocity fields are tested in a simulation of spatially developing turbulent channel flow. Synthetic turbulence generation methods that introduce realistic length scales are more suitable than uncorrelated random noise, but still require fairly long development lengths before realistic turbulence is established. A recycling method based on the use of turbulent data obtained from a separate calculation, in different flow conditions, was found to result in more rapid transition. A forcing method that includes a control loop also appears to be effective by generating turbulence with the correct Reynolds stresses and correlations within less than ten channel half heights. (C) American Institute of Physics.