The matching of polymer solution fast filament stretching, relaxation, and break up experimental results with 1D and 2D numerical viscoelastic simulation

This paper is concerned with the comparison of two numerical viscoelastic strategies for predicting the fast filament stretching, relaxation, and break up of low viscosity, weakly elastic polymeric fluids. Experimental data on stretch, relaxation, and breakup were obtained using a Cambridge Trimaster for a Newtonian solvent (diethyl phthalate) and three monodisperse polystyrene polymer solutions. Two numerical codes were tested to simulate the flow numerically. One code used a one-dimensional approximation coupled with the arbitrary Lagrangian-Eulerian approach and the other a two-dimensional axisymmetric approximation for the flow. In both cases, the same constitutive equations and mono and multimode parameter fitting were used, thereby enabling a direct comparison on both codes and their respective fit to the experimental data. Both simulations fitted the experimental data well and surprisingly the one-dimensional code closely matched that of the two-dimensional. In both cases, it was found necessary to utilize a multimode approach to obtain a realistic match to the experimental data. The sensitivity of the simulation to the choice of constitutive equation (Oldroyd-B and FENE-CR) and the magnitude of nonlinear parameters were also investigated. The results are of particular relevance to ink-jet processing and demonstrate that high shear rate, low viscosity viscoelastic polymeric flows can be simulated with reasonable accuracy.