论文标题
流动拓扑中的空间分辨拉伸伸展序列作为流体混合的基本结构
Spatially resolved stretching-rotation-stretching sequence in flow topology as elementary structure of fluid mixing
论文作者
论文摘要
我们对两种液体进行了二维数值模拟，这两种液体产生了两个在空间上可区分的范式速度流，即。很少有大型扩展涡旋和快速振荡。使用Okubo-Weiss标准，我们绘制了流场中拉伸和旋转的区域。我们发现，拉伸旋转拉伸的基本振荡序列会引起空间重新分布和浓度梯度的陡峭分布，而这种序列的聚集决定了下游位置的流体混合。此外，我们通过基于流量拓扑制定措施来量化“拉伸”和“折叠”的范例，这将有助于设计搅拌协议的设计。
We performed two-dimensional numerical simulations of passive stirring of two liquids which generated two spatially distinguishable paradigmatic velocity flows, viz. few large extended vortices and rapid oscillations. Using the Okubo- Weiss criterion, we mapped regions of stretching and rotation in the flow field. We find that an elementary oscillatory sequence of stretching-rotation-stretching induces spatial redistribution and steepening of concentration gradients, and the aggregation of such sequences determines fluid mixing at a downstream position. Furthermore, we quantify the paradigms of 'stretching' and 'folding' by developing measures based on flow topology which would facilitate the design of stirring protocols.
