Abstract
The flow behavior of polymer solutions among cylinders in a rectangular channel has been studied by means of flow visualization and particle image velocimetry. Cylinders are placed asymmetrically in a channel and there are narrow channels and wide channels formed by the offset positioning of circular-cylinder barriers. The fluids used here are polyacrylamide (PAA) 300ppm solution and Xanthan gum 800ppm solution, which show nearly the same shear viscosity. In this study, attention has been paid to the upstream region of the first cylinder. Owing to high extensional viscosity at high extensional rate, PAA solution cannot find its way into the narrow channel. In addition, difference of flow pattern in z-direction has been studied and extraordinary flow has been found that high velocity region appeared near the side wall in the upstream section.
