Like the generalized Newtonian outflow condition, the outflow condition for a viscoelastic flow consists of a zero tangential velocity. Instead of imposing the normal force, the viscoelastic outflow condition imposes a fully developed normal velocity profile, as in the inflow condition, but extra stresses are not imposed. The viscoelastic outflow condition makes it possible to prescribe flow boundary conditions in the presence of shear and nonzero normal forces. As for the inflow condition, the computational domain must be built in such a way that the basic assumptions of 1D Poiseuille flow are satisfied at the exit. The normal velocity profile is based on the flow rate that you specify. The convention is that an exiting flow is considered positive. The outflow condition should not be imposed at the exit of a free jet of a viscoelastic flow. For such cases, a zero normal force condition (see Normal and Tangential Force Condition) is preferred. The velocity distribution cannot be properly assigned since the geometric dimensions of the free jet are a priori unknown.