Experimental measurements of stretching fields in fluid mixing.
Experimental measurements of stretching fields in fluid mixing.
复制标题
流体混合中拉伸场的实验测量。
DOI：
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发表时间：
2002
影响因子：
8.6
通讯作者：
J. Gollub
中科院分区：
文献类型：
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作者：
G. Voth;George Haller;J. Gollub;J. Gollub
利用对产生混沌混合的二维流体中示踪粒子轨迹的精确测量，我们直接测量了随时间变化的拉伸场。这个量以前只能在数值上获得，它沿着与Poincaré映射的双曲不动点的稳定流形和不稳定流形重合的直线达到局部极大值。在每个瞬间，被动杂质场的轮廓被发现与最近经历了大伸展的线平行定向。局部伸展的幅度相差12个数量级。
Using precision measurements of tracer particle trajectories in a two-dimensional fluid flow producing chaotic mixing, we directly measure the time-dependent stretching field. This quantity, previously available only numerically, attains local maxima along lines that coincide with the stable and unstable manifolds of hyperbolic fixed points of Poincaré maps. Contours of a passive impurity field are found at each instant to be oriented parallel to the lines that have recently experienced large stretching. The local stretching varies by 12 orders of magnitude.