论文标题
客观涡流识别方法
An objective vortex identification method
论文作者
论文摘要
通常，涡流结构应与正在移动的观察者无关，尤其是当他们的坐标是非惯用性的时候，这可能会导致研究人员之间的通信困惑。不受坐标选择影响的属性称为客观。大多数情况下，研究人员希望在惯性坐标中收集数据，因为大多数物理定律在惯性坐标中都是有效的。结果，如何将非惯性坐标中的观测值转移到惯性坐标中的观测值会引起利益。在本文中，提供了从非惯性观察的惯性坐标中获得速度和速度梯度张量的方法，该观察值基于一个已知的零涡度点可以从物理事实中选择，例如该点位于Indiscid区域中。根据目标涡度，可以从目标涡度结构中计算出客观的涡度结构。选择liutex作为涡旋的指标，使用两个数值示例来测试所提出的方法。结果表明该方法的性能非常好，并且相对误差极小。
Generally, the vortex structures should be independent of the observers who are moving, especially when their coordinates are non-inertial, which may result in confusions in communications between researchers. The property that not being influenced by the choice of coordinate is called objective. Mostly, researchers would like to gather data in the inertial coordinate because most physical laws are valid in the inertial coordinate. As a result, how to transfer the observations in a non-inertial coordinate to those in an inertial coordinate raises interest. In this paper, methods are provided to obtain velocity and velocity gradient tensor in an inertial coordinate from the non-inertial observations based on one known zero-vorticity point which can be chosen from physical fact such as the point is located in the inviscid region.Further, objective vortex structure can be calculated from the objective velocity or velocity gradient tensor. With Liutex chosen as the indicator of the vortex, two numerical examples are used to test the proposed methods. The results show that the methods perform very well and the relative error is extremely small.
