Elastic secondary flows of semidilute DNA solutions in abrupt 90° microbends
Elastic secondary flows of semidilute DNA solutions in abrupt 90° microbends
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DOI：
10.1103/physreve.78.036314
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发表时间：
2008-09-01
影响因子：
2.4
通讯作者：
Muller, Susan J.
中科院分区：
文献类型：
--
作者：
Gulati, Shelly;Liepmann, Dorian;Muller, Susan J.
在中等弹性水平的突然平面 90 S 微弯中的半稀释 lambda-DNA 溶液中，发现了牛顿流中不存在的二次流。流动可视化和微粒图像测速实验表明，存在于弯管上游内角的涡流随着雷诺数和魏森伯格数的增加而增大（9.9 x 10(-7) < Re < 3.1 x 10(-2), 0.41 < Wi < 126 ）。涡流增长被量化为弹性函数；在高弹性下，涡流占据了上游通道的很大一部分并扭曲了主流。弹性涡流的存在（分子可以长时间被困在弹性涡流中）对于处理生物大分子的微器件的设计具有重要意义。
Secondary flows that are absent in Newtonian flows are found for semidilute lambda-DNA solutions in abrupt planar 90 S microbends at modest levels of elasticity. Flow visualization and microparticle image velocimetry experiments show that a vortex, which is present in the inner, upstream corner of the bend, grows with increasing Reynolds and Weissenberg number (9.9 x 10(-7) < Re < 3.1 x 10(-2), 0.41 < Wi < 126 ). The vortex growth is quantified as a function of elasticity; at high elasticity, the vortex occupies a significant fraction of the upstream channel and distorts the primary flow. The presence of elastic vortices, in which molecules can become trapped for long times, has implications for the design of microdevices for the processing of biological macromolecules.