Abstract
In this study,we have investigated the mixing property of water and polymer solution in microchannels.We have utilized T-shaped microchannels which have contraction-expansion parts with five asymmetric rectangular block gates and observed the mixing procedure.Dyed water and a dilute aqueous solution of polyethylenoxide(PEO) of 10ppm,30ppm,50ppm and 100 ppm by weight were mixed in the tests.In microchannels,the polymer solution caused unstable vortexes before the rectangular gates and the instability of the flow grew at the later part of the contraction-expansion region.The unstable flow with the vortex due to the elastic property of the polymer solution leaded the efficient mixing.Most efficient mixing was obtained at some Re number,and the efficient mixing for wider range of Re number was obtained with microchannel having shorter pitch of the gates.
