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Simulation of three‐dimensional polymer mould filling processes using a pseudo‐concentration method
Author(s) -
Haagh G. A. A. V.,
Van De Vosse F. N.
Publication year - 1998
Publication title -
international journal for numerical methods in fluids
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.938
H-Index - 112
eISSN - 1097-0363
pISSN - 0271-2091
DOI - 10.1002/(sici)1097-0363(19981215)28:9<1355::aid-fld770>3.0.co;2-c
Subject(s) - boundary value problem , mechanics , singularity , slip (aerodynamics) , no slip condition , finite element method , flow (mathematics) , displacement (psychology) , mathematics , engineering , geometry , physics , structural engineering , mathematical analysis , mixed boundary condition , psychology , psychotherapist , aerospace engineering
Mould filling processes, in which a material flow front advances through a mould, are typical examples of moving boundary problems. The moving boundary is accompanied by a moving contact line at the mould walls causing, from a macroscopic modelling viewpoint, a stress singularity. In order to be able to simulate such processes, the moving boundary and moving contact line problem must be overcome. A numerical model for both two‐ and three‐dimensional mould filling simulations has been developed. It employs a pseudo‐concentration method in order to avoid elaborate three‐dimensional remeshing, and has been implemented in a finite element program. The moving contact line problem has been overcome by employing a Robin boundary condition at the mould walls, which can be turned into a Dirichlet (no‐slip) or a Neumann (free‐slip) boundary condition depending on the local pseudo‐concentration. Simulation results for two‐dimensional test cases demonstrate the model's ability to deal with flow phenomena such as fountain flow and flow in bifurcations. The method is by no means limited to two‐dimensional flows, as is shown by a pilot simulation for a simple three‐dimensional mould. The reverse problem of mould filling is the displacement of a viscous fluid in a tube by a less viscous fluid, which has had considerable attention since the 1960's. Simulation results for this problem are in good agreement with results from the literature. © 1998 John Wiley & Sons, Ltd.