Ratio of Outflow Rate of Viscoelastic Fluids through a Branching Channel

The flow rate balance of viscoelastic fluids through a branching channel with two exits, which were different in width, was studied. Numerical simulations of the viscoelastic flow in branching channels were carried out by the stream-upwind finite element method. The Gie sekus model with a single relaxation time was used for a constitutive equation. The Bird carreau model which was one of generalized Newtonian models was also used in order to separate the contribution of elasticity. The shear-thinning property in viscosity causes the in crease in the ratio of the flow rate in the wider slit to the total flow rate with increasing flow rate. Furthermore, the stretch-thickening property in elongational viscosity promotes the ten dency. Therefore, for viscoelastic fluids, both the shear viscosity and the elongational viscos ity affect the flow rate balance.