Coarse grained scale of turbulent mixtures.
Coarse grained scale of turbulent mixtures.
复制标题
湍流混合物的粗粒尺度。
DOI：
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发表时间：
2006
影响因子：
8.6
通讯作者：
J. Duplat
中科院分区：
文献类型：
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作者：
E. Villermaux;J. Duplat
支持搅拌混合物中浓度含量的物理长度尺度是多少？在搅拌混合物中常见的长度标尺中有一个耗散标尺，它平衡了基片变形和扩散涂抹率。该尺度是变形速率的递减函数，因此也是湍流中雷诺数的递减函数。实验表明，混合料浓度定义在基本砖ETA=LSC(-2/5)较大的支撑体上。它的尺度就像L的搅拌秤，依赖于施密特数SC，与雷诺数无关。上述定律得到了L二十年和SC三十年的测量结果的支持。我们认为，这种尺度是在大尺度衬底形变下基元拉伸标量片束合并的结果。
What is the physical length scale which supports the concentration content in a stirred mixture? Among the length scales familiar in stirred mixtures is the dissipation scale which equilibrates substrate deformation and diffusive smearing rates. That scale is a decreasing function of the deformation rate and is, thus, a decreasing function of the Reynolds number in turbulent flows. Experiments show that the mixture concentration content is defined on a support whose elementary brick eta=LSc(-2/5) is much larger. It scales like the stirring scale L, depends on the Schmidt number Sc, and is independent of the Reynolds number. The above law is supported by measurements covering two decades in L and three decades in Sc. We suggest that this scale results from the aggregation of bundles of elementary stretched scalar sheets merging under large-scale substrate deformation.