2008 Volume 3 Issue 8 Pages 987-998
Flows of polymer solutions through a 3.7:1 abrupt contraction were observed in a micro- and a regular-size channels with rectangular cross sections. The test fluids are three kinds of 0.2 wt% aqueous solutions of polyacrylamide whose rheological properties are different with each other. In the previous works, apparent slips were observed on the channel wall for the polymer solutions and the slip levels of these solutions are considered to be different. In the present paper, the growth of the salient corner vortex is discussed as a function of the shear rate. Consequently, the vortex size in the microchannel is larger than that in the regular-size channel for the flow of polymer solution whose slip level is weak, whereas the vortex size in the microchannel is smaller than that in the regular-size channel for the flow of polymer solution whose slip level is strong.
