CHARACTERIZATION OF THE LOW-PRESSURE FILAMENTS IN A THREE-DIMENSIONAL TURBULENT SHEAR FLOW
CHARACTERIZATION OF THE LOW-PRESSURE FILAMENTS IN A THREE-DIMENSIONAL TURBULENT SHEAR FLOW
复制标题
三维湍流剪切流中低压细丝的表征
DOI：
10.1063/1.868586
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发表时间：
1995
影响因子：
4.6
通讯作者：
Y. Couder
中科院分区：
文献类型：
--
作者：
O. Cadot;S. Douady;Y. Couder
本文给出了在三维湍流中自发出现的低压细丝的结果。通过研究流动显示与局部压力和速度测量之间的相关性，首先获得了细丝的单个特征。然后，统计研究的时间记录的压力，表现出间歇性的短和深的下降是提出。结果表明，压力直方图仅依赖于注入速度的平方，强凹陷的产生速率与雷诺数无关。这些结果对细丝形成的可能机制施加了严格的限制；它们与一个简单的模型相一致，在这个模型中，细丝的形成主要是由于拉伸剪切层的部分卷起。在这个模型中，压力细丝和涡度细丝的层次是不同的：具有最大凹陷的细丝是最厚（和最长）的，而具有最强涡度的细丝可能是最薄（和最短）的。
In this paper results on the low‐pressure filaments that appear spontaneously in three‐dimensional turbulent flows are presented. An individual characterization of the filaments is first obtained by studying the correlations between the flow visualization and local measurements of the pressure and the velocity. Then, a statistical study of the time recordings of the pressure that exhibits intermittent short and deep depressions is presented. It is shown that the pressure histograms depend only on the square of the injection velocity, and that the rate of production of strong depressions is independent of the Reynolds number. These results impose severe constraints on the possible mechanisms of formation of the filaments; they are consistent with a simple model, in which the formation of the filaments results primarily from the partial rollup of stretched shear layers. In this model there is a difference between the hierarchies of pressure and vorticity filaments: the filaments with the largest depression are the thickest (and the longest), while the filaments with the strongest vorticity are likely to be the thinnest (and shortest).