S0501-2-4 マイクロチャネル内の渦を伴う縮小流におけるDNA高分子の伸張変形(複雑流体の流動現象(2))

Abstract

Flow behaviors of polymer solution in oscillatory flow have been investigated with a micro abrupt contraction channel. Fluorescently-stained DNA polymer solutions have been utilized to observe the flow patterns with fluorescent microscope. In conversing flow periods in the micro oscillatory flow, corner vortexes were generated and grew to a maximum size, but no separation or no vortex was observed in diverging flow period. In the cases of large amplitude oscillatory flow, the vortexes were generated in the first half accelerating flow from flow reversal and grew even in the later half decelerating flow. When the amplitude was small, the vortexes were generated in the latter decelerating flow. It is considered that these results meant vortex generation was affected not only instantaneous condition but also flow history. The maximum size of the vortexes was comparable to the amplitude of the oscillatory flow.