TY - JOUR
T1 - Numerical simulations of the planar contraction flow for a polyethylene melt using the XPP model
AU - Verbeeten, W.M.H.
AU - Peters, G.W.M.
AU - Baaijens, F.P.T.
PY - 2004
Y1 - 2004
N2 - The Discrete Elastic Viscous Stress Splitting technique in combination with the Discontinuous Galerkin (DEVSS/DG) method is used to simulate a low density polyethylene melt flowing in a transientcontraction flow problem.Numerical results using the original and a modified form of the eXtended Pom-Pom (XPP) model are compared to numerical results obtained with the exponential form of the Phan-Thien Tanner (PTT-a) and the Giesekus model and to experimental data of velocities and stresses. These models are known to be well capable of predicting all characteristic features encountered experimentally.Curiously, the eXtended Pom-Pom mode, formulated with the same non-affine or irreversible stretch dynamics as the original Pom-Pom model, encounters convergence problems using the DEVSS/DG method. A slight modification of the stretch dynamics such that it becomes consistent with other viscoelastic models and in agreement with a modification of the stretch dynamics based on non-equilibrium thermodynamics by van Meerveld [J. Non-Newtonian Fluid Mech.,108: 291-299, 2002] gives a more numerical stable behavior and steady state could be reached. From this it is clear that physical and numerical issues still play a mixed role in numerical viscoelastic flow problems
AB - The Discrete Elastic Viscous Stress Splitting technique in combination with the Discontinuous Galerkin (DEVSS/DG) method is used to simulate a low density polyethylene melt flowing in a transientcontraction flow problem.Numerical results using the original and a modified form of the eXtended Pom-Pom (XPP) model are compared to numerical results obtained with the exponential form of the Phan-Thien Tanner (PTT-a) and the Giesekus model and to experimental data of velocities and stresses. These models are known to be well capable of predicting all characteristic features encountered experimentally.Curiously, the eXtended Pom-Pom mode, formulated with the same non-affine or irreversible stretch dynamics as the original Pom-Pom model, encounters convergence problems using the DEVSS/DG method. A slight modification of the stretch dynamics such that it becomes consistent with other viscoelastic models and in agreement with a modification of the stretch dynamics based on non-equilibrium thermodynamics by van Meerveld [J. Non-Newtonian Fluid Mech.,108: 291-299, 2002] gives a more numerical stable behavior and steady state could be reached. From this it is clear that physical and numerical issues still play a mixed role in numerical viscoelastic flow problems
U2 - 10.1016/j.jnnfm.2003.12.003
DO - 10.1016/j.jnnfm.2003.12.003
M3 - Article
SN - 0377-0257
VL - 117
SP - 73
EP - 84
JO - Journal of Non-Newtonian Fluid Mechanics
JF - Journal of Non-Newtonian Fluid Mechanics
IS - 2-3
ER -