On the relationships between local vortex identification schemes
On the relationships between local vortex identification schemes
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DOI：
10.1017/s0022112005004726
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发表时间：
2005-07-25
影响因子：
3.7
通讯作者：
Adrian, RJ
中科院分区：
文献类型：
--
作者：
Chakraborty, P;Balachandar, S;Adrian, RJ
我们分析了目前流行的涡流识别标准，是基于逐点分析的速度梯度张量。本文提出了一种新的涡旋物质轨道螺旋压缩性的度量方法，并利用这种度量方法提出了一种新的局部涡旋识别准则和对涡核的要求。不同的标准之间的相互关系进行了探讨分析，并在几个流的例子，使用零和非零阈值的识别参数。这些相互关系提供了一个新的解释的各种标准的局部流动运动学。一个典型的湍流的例子进行了研究，并观察到，所有的标准，给定的阈值的建议使用，结果非常相似的旋涡结构。一个统一的解释的基础上，当地流动运动学的相似性或差异时，可以预期的涡结构推导出使用不同的标准。
We analyse the currently popular vortex identification criteria that are based on point-wise analysis of the velocity gradient tensor. A new measure of spiralling compactness of material orbits in vortices is introduced and using this measure a new local vortex identification criterion and requirements for a vortex core are proposed. The interrelationships between the different criteria are explored analytically and in a few flow examples, using both zero and non-zero thresholds for the identification parameter. These inter-relationships provide a new interpretation of the various criteria in terms of the local flow kinematics. A canonical turbulent flow example is studied, and it is observed that all the criteria, given the proposed usage of threshold, result in remarkably similar looking vortical structures. A unified interpretation based on local flow kinematics is offered for when similarity or differences can be expected in the vortical structures educed using the different criteria.