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3D models fail in Comsol 4.2, worked in 4.1
Posted 2011年7月29日 GMT-4 17:32 Fluid & Heat, Microfluidics Version 4.2 0 Replies
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Hello All,
I've been using Comsol regularly for about 1.5 years in grad school now, and have a decent sized library of simulations and models I've created and run.
Recently I was working on a 2D model that needed some reaction kinetic stuff--specifically the Langmuir Binding Model--and in order to include the necessary PDEs I had to upgrade from v4.1 to v4.2. No big deal, we had it around just hadn't installed it yet. Upgraded it, got the PDEs working, so far so good.
But since upgrading I haven't been able to get a single 3D model to work. None of my old simulations work--transient models fluid flow with Transport of Diluted Species, Fluid-Structure Interactions, even a very basic "force applied to end of a cantilever" fails. These are all files that have, in the past, worked successfully and repeatedly under different parameters. Now, no matter what, they either fail to converge or, in the case of the Fluid-Structure Interaction, just don't progress in their solution (I let it run for over 18 hours and it never moved passed two dots in the "segregated solver" plot; the exact same file took less than 2 hours when on v4.1).
Is there some sort of trick to getting this to work? Are there new options I am completely skipping over that help 3D simulations work?
2D simulations work alright, although with the Transport of Diluted Species it is remarkably sensitive to how long the simulation runs for (that is, if I set it to run from 0 to 10 using 0.5 increments it will say "failed to converge" or even fail on the Jacobian, whereas simply changing the time up to 20 will successfully work).
TL;DR: Comsol v4.2 has made almost all of my simulations unusable. I've gotten 2D models working if I redo them from scratch, but I can't get 3D models to work no matter what I do.
EDIT: As I am writing this, I was able to get the "force applied to end of cantilever" 3D simulation working. I ran it before writing, it failed; I reloaded a different version, it worked; reloaded file that failed just before and it worked.
Any suggestions are appreciated.
Hello Tim Gustafson
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