Assessment of LES quality measures using the error landscape approach
Assessment of LES quality measures using the error landscape approach
复制标题
使用误差景观方法评估 LES 质量测量
DOI：
10.1007/978-1-4020-8578-9_11
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发表时间：
2008
期刊：
影响因子：
--
通讯作者：
B. Geurts
中科院分区：
文献类型：
--
作者：
M. Klein;J. Meyers;B. Geurts
均匀各向同性衰减湍流的大涡模拟数据库被用来评估文献中提出的四种不同的LES质量措施。采用Smagorinsky亚网格模式，系统地改变涡粘性参数CS和网格间距h。结果表明，两种方法定性预测的基本特征的错误景观，包括一个最佳的细化轨迹。这些方法基于Richardson外推法的变体，并假设数值误差和建模误差随网格尺寸的幂而变化。因此，他们需要在几个网格上的模拟相结合。结果表明，一个近似的最优的细化策略可以构造基于LES输出，而不需要DNS数据。与完整误差图的比较表明了不同方法在均匀湍流误差评估中的适用性。研究了不同Smagorinsky参数和不同网格尺寸下，估算的湍流动能误差与DNS计算的“真实”湍流动能误差的比值。该量对于减小网格尺寸的行为进一步深入了解了这些方法的可靠性。
A large-eddy simulation database of homogeneous isotropic decaying turbulence is used to assess four different LES quality measures that have been proposed in the literature. The Smagorinsky subgrid model was adopted and the eddy-viscosity `parameter' CS and the grid spacing h were varied systematically. It is shown that two methods qualitatively predict the basic features of an error landscape including an optimal refinement trajectory. These methods are based on variants of Richardson extrapolation and assume that the numerical error and the modelling error scale with a power of the mesh size. Hence they require the combination of simulations on several grids. The results illustrate that an approximate optimal refinement strategy can be constructed based on LES output only, without the need for DNS data. Comparison with the full error landscape shows the suitability of the di®erent methods in the error assessment for homogeneous turbulence. The ratio of the estimated turbulent kinetic energy error and the `true' turbulent kinetic energy error calculated from DNS is studied for different Smagorinsky parameters and different grid sizes. The behaviour of this quantity for decreasing mesh size gives further insight into the reliability of these methods.