2021 Volume 77 Issue 2 Pages I_129-I_136
A computational method was proposed to calculate the viscoelastic fluid flows with free surfaces, which are the boundaries between viscoelastic fluids and surrounding Newtonian fluids. In the proposed method, phase-averaged governing equations for the fluids are solved using the finite volume method in the collocated grid system. The Giesekus model, which is a nonlinear viscoelastic model, is used as the constitutive equation of the viscoelastic fluid. The proposed method was first applied to the flows of Newtonian and viscoelastic fluids between parallel plates. As a result, it was confirmed that distributions of calculated velocity and viscoelastic stresses in steady-state are in good agreement with theoretical solutions. In addition, the die swell phenomenon was calculated. The viscoelastic fluid was injected into the area filled with the Newtonian fluid from a gap between parallel plates. It was shown that the proposed method enables us to predict the swelling of the injected viscoelastic fluid as reported in the preceding studies.
