Influence Of Advection Differencing Error Upon Large-Eddy Simulation Accuracy
Influence Of Advection Differencing Error Upon Large-Eddy Simulation Accuracy
复制标题
平流差分误差对大涡模拟精度的影响
DOI：
10.1023/a:1018734205850
复制
发表时间：
2001
影响因子：
4.3
通讯作者：
T. Haack
中科院分区：
文献类型：
--
作者：
J. W. Glendening;T. Haack
大涡模拟（LES）模型对湍流特征的准确预测需要对非线性平流项进行精确的数值计算。在存在平均风的情况下，使用二阶或四阶有限差分会在高波数处产生很大的湍流能量损失，这与这些格式的理想数值特性不准确。离散差分的不准确性也影响小波数“大涡”结构和水平平均湍流量。使用高精度伪光谱技术，这种能量损失不会发生，光谱行为对应于滤过的kolmogorov理论预测到去混叠截止波数。通过对平行项的伽利略变换，极大地改善了有限差分格式的不准确性。
Accurate prediction of turbulent features by alarge-eddy simulation (LES) model requires accuratenumerical evaluation of the nonlinear advective terms. In the presence of a mean wind, use of second-order orfourth-order finite differencing produces large lossesof turbulent energy at high wavenumbers, an inaccuracyconsistent with idealized numerical properties ofthese schemes. The discrete differencing inaccuraciesalso affect the small wavenumber ``large eddy''structure and the horizontally-averaged turbulentquantities. With a high accuracy pseudospectraltechnique, this energy loss does not occur andspectral behaviour corresponds to filtered Kolmogorovtheory predictions out to the de-aliasing cutoffwavenumber. The inaccuracy of the finite differenceschemes is greatly ameliorated through a Galileantransformation of the advective term.