抄録
Two-dimensional viscoelastic flows in T-shaped channels were observed by means of a flow visualization technique. We observed two kinds of T-shaped junction flows: symmetric and asymmetric junctions referred to as “type A” and “type B”. Fluids used were water solutions of polyacrylamide and dextrose syrup respectively as viscoelastic and viscous liquids.
In type A flow of viscoelastic fluid, two circulating secondary flows were observed at the upstream sides of entrance corners, but, with purely viscous fluid, they were not observed. With viscoelastic liquids flow direction changed more abruptly at the junction than with viscous fluids. In type B flows, circulating secondary flows were observed at higher flow rates than in type A flows.
Lastly, flows were numerically simulated using the Maxwell constitutive model in perturbation method. Numerical results agreed qualitatively with experimental results in type A flows, but did not agree well in type B flows.
