Viscoelastic Combining Flow in a T-shaped Tube

A viscoelastic combining flow in a T-shaped tube is examined using polymer (polyacrylamide) solutions. Streamlines near the combining part were observed from the two- or three-dimensional standpoint of view. Upstream of the combining part, circulating secondary flows were observed in the T-shaped tube as well as in a T-shaped channel composed of parallel plates. The streamline length changes according to the growth of the circulating secondary flow. Curves of streamline length plotted with Weissenberg number present an elastic effect of viscoelastic liquid and nearly become one straight line for the various throttling ratios and polymer concentrations. Hence, the elastic property of polymer solution contributes to the growth of the circulating secondary flow for the T-shaped combining tube flow.