Dear OGS-users,
quick update and summary on the "problem" I reported last week on the mailing list.
I was not successful to get "near-zero" velocities for a "no-flow" problem if there are strong permeability contrasts present (i.e. more than 8 orders of magnitude difference between an open fracture and some low permeability rock).
Interestingly, we solved the case also with COMSOL and encountered the same problem/effect (direct solver). Residual velocities are relatively high for strong permeability differences and very low for more a homogeneous permeability field.
This are good news for OGS, as the problems are probably not related to a problem in the code itself. Of course it might be a problem with the FE-method in general, or the problem is rather ill-posed....
Greetings, Georg
Georg,
Thank you for sharing the problem with us. If you want to have real no flow in some part of your domain, an ad-hoc solution would be deactivating sub-domains by specifying material IDs only for flow process.
Best
Nori
···
On 02/15/2013 11:01 AM, Georg Kosakowski wrote:
Dear OGS-users,
quick update and summary on the "problem" I reported last week on the
mailing list.
I was not successful to get "near-zero" velocities for a "no-flow"
problem if there are strong permeability contrasts present (i.e. more
than 8 orders of magnitude difference between an open fracture and some
low permeability rock).
Interestingly, we solved the case also with COMSOL and encountered the
same problem/effect (direct solver). Residual velocities are relatively
high for strong permeability differences and very low for more a
homogeneous permeability field.
This are good news for OGS, as the problems are probably not related to
a problem in the code itself. Of course it might be a problem with the
FE-method in general, or the problem is rather ill-posed....
Greetings, Georg
--
Norihiro Watanabe
Department of Environmental Informatics (ENVINF)
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