Dear Dmitry,
but then I don't see the point why you want to use a compositional model.
Couldn't you simply use the dumux/porousmediumflow/2p model?
Best regards,
Martin
On 25.03.20 18:02, Dmitry Pavlov wrote:
Dear Martin,
Thank you for a quick reply. I am currently dealing with a two-phase
two-component Darcy flow of water and oil. Both liquids are
incompressible and have constant viscosity. Gravity, thermal transfer
and diffusion are not considered. Custom functions are provided for
capillary pressure, relative permeability for water, and relative
permeability for oil. Is more information needed?
Initially, I wrote my program basing on the example
test/porousmediumflow/2p/sequential/test_mpfa2p, and it worked; now I
am exploring the implicit method option.
Best regards,
Dmitry
On 25.03.2020 19:50, Martin Schneider wrote:
Dear Dmitry,
the compositional models in Dumux take into account diffusion effects
between the different fluid phases,
which is why you can't use an immiscible fluidsystem.
Could you maybe send some more details about your equations you want
to solve
and about the phases and components that are involved.
Best regards,
Martin
On 25.03.20 17:36, Dmitry Pavlov wrote:
Dear Martin,
Following your advice, I decided to try an implicit model of my
problem, namely a PorousMediumFlowProblem, following the example in
tests/porousmediumflow/2pnc/implicit/diffusion.
I managed to compile it, but am getting a runtime error upon the
start and, honestly, have no idea what to do about it. I will
appreciate any pointers.
For convenience, I will describe my task again. I am trying to
simulate a two-phase two-component flow on a 2D rectangular area
with one border being the influx and the opposite one being the
outflow (setOutflow()). Two other two borders are walls, of course,
with setAllNeumann().
The fluid system is realized as a TwoPImmiscible of two
OnePLiquid-s. The first of the liquids is the wetting phase, the
second is the nonwetting phase.
Now, the error that I am getting is
Dune reported error: Dune::InvalidStateException
[binaryDiffusionCoefficient:.../dumux/dumux/material/fluidsystems/2pimmiscible.hh:462]:
Binary diffusion coefficients of components are meaningless if
immiscibility is assumed
I never any "binary diffusion coefficients" directly in my files, so
it comes from the method.
I have doubts about the following line of my program
values.setState(Indices::bothPhases);
which is present in dirichletAtPos(), neumannAtPos(), and
initialAtPos() implementation. I do not really understand what does
this setState() setting mean, so I kind of guessed.
Am I on the right path at all here? I can provide more details, of
course, if that helps to understand what is going on.
Best regards,
Dmitry
On 23.03.2020 20:59, Martin Schneider wrote:
Dear Dmitry,
most of the Dumux users are using the fully-coupled (implicit) models.
The sequential methods have not really been further developed (at
least the discretization schemes)
over the last few years.
However, if you want to use the MPFA-L method you have to use the
sequential method.
The implicit models only support the MPFA-O scheme.
Best regards,
Martin
On 23.03.20 18:53, Dmitry Pavlov wrote:
Dear Martin,
I guess not, I took the first one that worked, after numerous
failed attempts with other methods taken from random examples,
though the said attempts might have failed because of me being a
non-experienced user, and not because of the nature of the
methods. Would you suggest to use an implicit method instead?
Best regards,
Dmitry
On 23.03.2020 20:48, Martin Schneider wrote:
Dear Dmitry,
if I remember correctly, the sequential MPFA-L scheme requires
that each vertex is surrounded by 4 quadrilaterals (in 2D).
If this is not the case, the construction of interaction volumes
fails.
Is there any reason why you are using the sequential method?
Best regards,
Martin
On 23.03.20 18:42, Dmitry Pavlov wrote:
Dear Kilian,
1.) You should be able to use more recent versions of gmsh if you go to File ->
Export. If you name your grid *.msh
there will be an option to chose the older Version II ASCII format, readable by
Dumux.
Thank you!
2.) Have you tried an unstructured grid with quadrilaterals? According to the
header where the error comes from,
only quadrilaterals are supported (at least, this is what some comments in the
code suggest). You can force gmsh to
use only quads (also unstructured ones).
I just tried an unstructured quad grid and got the same error.
However, a gmsh-generated structured quad grid went fine, which
means that there is no trouble with gmsh itself.
Good news: using FVPressureTwoPAdaptive instead of
FvMpfaL2dPressureTwoP allowed me to use an gmsh-generated
unstructured grid (both triangular and quadrilateral). I am
wondering whether MPFA-L in DuMux "officially" requires a
structured quad grid.
Best regards,
Dmitry
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