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3-D Oxygen diffusion multiphysics model to simulate shelf-life urgent please!!
Posted May 3, 2014, 3:19 a.m. EDT Chemical Reaction Engineering Version 4.3b 0 Replies
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i'm trying to solve a problem concerning the permeation of oxygen in a 3-D object where i have an internal gas headspace ("Transport of species concentrated)and other internal water domain (Transport in species diluited").The external domains are plastics modelled with a "Flow in porous media".
The B.C. are concentration on the external surfaces fixed (Coxigenair) instead in the internal surfaces I made some boundary pairs and fixed "continuity" B.C.. The problem is time dependent and i want know the concentration in the water during an year of time.
The mesh is a simple tetrahedral mesh physics controlled.The solver used is the GMRES with default parameters.
Now i have set all the model but i have a warning with the geometry imported to CAD model. I have an edge smaller the minimum dimension (also with Extra fine).
Now i found this error:
"Very ill conditioned preconditioner: The relative residual is more than 1000 times larger than the relative tolerance.
What's the problem??Depend on the geometry warning How i could set the solver??
Thanks in advance
Hello S. Desiderio
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