The effect of numerical errors and turbulence models in large-eddy simulations of channel flow, with and without explicit filtering
The effect of numerical errors and turbulence models in large-eddy simulations of channel flow, with and without explicit filtering
复制标题
有或没有显式滤波的通道流大涡流模拟中数值误差和湍流模型的影响
DOI：
10.1017/s0022112003006268
复制
发表时间：
2003
影响因子：
3.7
通讯作者：
F. Chow
中科院分区：
文献类型：
--
作者：
J. Gullbrand;F. Chow
采用二阶和四阶有限差分程序对槽道湍流进行数值模拟。系统地比较了不同网格分辨率、有限差分格式和几种湍流闭合模式下的大涡模拟结果。将使用显式滤波来减少数值误差的结果与传统大涡模拟方法的结果进行了比较。由于本研究的结果是为了将大涡模拟应用于复杂区域，所以使用了在光谱空间中光滑的滤波函数。显式滤波引入了可分辨的子滤波尺度(RSFS)和次网格尺度(SGS)湍流项。前者在理论上是可以重建的；后者必须进行建模。研究了动态Smagorinsky模型、动态混合模型和新的动态重构模型。结果表明，对于显式滤波，增加RSFS应力的重建层数可以改善平均速度和湍流强度。与未加显式滤波的大涡模拟相比，平均速度分布差异不大，但显式滤波后的湍流强度有所改善。
Turbulent channel flow simulations are performed using second- and fourth-order finite difference codes. A systematic comparison of the large-eddy simulation (LES) results for different grid resolutions, finite difference schemes, and several turbulence closure models is performed. The use of explicit filtering to reduce numerical errors is compared to results from the traditional LES approach. Filter functions that are smooth in spectral space are used, as the findings of this investigation are intended for application of LES to complex domains. Explicit filtering introduces resolved subfilter-scale (RSFS) as well as subgrid-scale (SGS) turbulence terms. The former can be theoretically reconstructed; the latter must be modelled. The dynamic Smagorinsky model, the dynamic mixed model, and the new dynamic reconstruction model are all studied. It is found that for explicit filtering, increasing the reconstruction levels for the RSFS stress improves the mean velocity as well as the turbulence intensities. When compared to LES without explicit filtering, the difference in the mean velocity profiles is not large; however the turbulence intensities are improved for the explicit filtering case.