钝体尾流的双重小波包分解

根据湍流相干结构和非相干结构不相关的特性，提出了一种钝体尾流双重小波包分解的新算法，将湍流的运动分解成相干分量和非相干分量，该算法以湍流相干分量和非相干分量的相关系数作为迭代的控制指标，减小了过去算法中的随意性，用该算法对大长宽比的钝体尾流三维超声波流速仪测量数据的分析表明：1)钝体间距与宽度之比大于4时，钝体间的相互影响可以忽略不计；2)流线型的钝体尾流紊动强度较小。

A Dual Decomposition Algorithm for Turbulent Wake Flows After Blunt Bodies Using the Wavelet Packet Method

Based on the wavelet packet method, a dual decomposition algorithm for extracting coherent structures from turbulent wake flows after blunt bodies is presented. The correlation between coherent and incoherent motions is used as iteration criterion since the coherent and incoherent motions are uncorrelated. Thus, a priori knowledge about the flows is no necessary in turbulent wake flow decomposition by means of this method. This method is used for decomposing the velocity data measured by ADV in the wake flows of trashrack with large length-to-width ratio. The results show that: 1) trashracks do not interfere with one another when the trashrack spacing-to-width ratio is not small than 4, 2) turbulent intensity of the wake flow for the trashrack with streamlined profiles is much small.