> On 5. Dec 2018, at 12:04, lc <[email protected]> wrote:
>
> Dear Beatrix,
>
> thank you for the hints. I read the documentation but still I'm wondering if
> it is the proper behaviour what I get in the previous figure. Also, should I
> expect problems swithching from cartesian to unstructured grids?
>
Hi Lorenzo,
there are too many possible answers to this question, you have to be more
specific. Which type of problem do you expect when switching to unstructured
grids? Which problem are you trying to solve? What does the setup look like?
Did you try switching to unstructured grids and experienced any problems?
In order to get better answers on the mailing list, and answers that are also
useful to others,
please stick to the following format when asking questions on the mailing list:
1) What are you trying to do with Dumux?
2) What is the problem that came up? How can we reproduce it? (Is it a general
problem or a problem for you in the particular case?)
3) What have you tried so far to solve the problem?
4) Post error logs (full error message), CMake logs, code snippets if helpful
(It should be immediately visible what you are referring to, do not just post
five C++ headers with your entire setup)
and describe them in detail in your question.
Furthermore, please do not use the Dumux mailing list to ask _general_
questions about porous media flow, mathematics, numerics, discretisation
methods, C++, etc. Please consult the respective literature.
Best wishes
Timo
> Thank you again,
> Lorenzo
>
> On 05.12.2018 13:36, Beatrix Becker wrote:
>> Dear Lorenzo,
>>
>> There is a list of run-time parameters on the Dumux website, e.g. for the
>> 2.12 release: https://dumux.org/doxygen/2.12/a06491.HTML
>> <https://dumux.org/doxygen/2.12/a06491.HTML>
>>
>> All run-time parameters are explained there. Does that help you?
>> Additionally, it is always a good idea to have a look at the code to
>> understand what it does. Simply grep for something that you are wondering
>> about, e.g. by typing when you are in the dumux-module folder
>>
>> grep -r "EnableInitializationIndicator"
>>
>> The console will print parts of the code, which may be enough to get some
>> understanding, and additionally you can open the files and read through the
>> code.
>>
>> I do not understand your question about the alugrid.cfg file... I never did
>> anything in particular with it.
>>
>> Best regards,
>> Beatrix
>>
>>
>> Am 05.12.18 um 10:56 vorm. schrieb lc:
>>> Hello,
>>>
>>> thanks for the previous answer, it was helpful.
>>>
>>> About grid adaptation, I tried but I get strange refinement, as reported in
>>> the figure.
>>>
>>> In particular, I don't know how to set this block:
>>>
>>> [GridAdapt]
>>> EnableInitializationIndicator = 1
>>> RefineAtDirichletBC = 1
>>> RefineAtFluxBC = 2
>>> MinLevel = 0
>>> MaxLevel = 2
>>> RefineTolerance = 0.05
>>> CoarsenTolerance = 0.001
>>>
>>> Also, should I use the alugrid.cfg file? At the moment I don't use.
>>> May you give me some hints please?
>>>
>>> Kind regards,
>>> Lorenzo
>>>
>>> On 03.12.2018 15:41, Gläser, Dennis wrote:
>>>> Hi Lorenzo,
>>>>
>>>> regarding your point (3):
>>>>
>>>> Let us consider the mass balance equation for one of the phases. Then, for
>>>> outflow BCs the flux across the boundary is computed by using the current
>>>> pressure gradients. For a darcy flux this would mean -(K*gradP)*normal is
>>>> evaluated on the boundary. Afterwards, the flux is turned into a mass flux
>>>> by multiplying with the mobility and the density, for which we typically
>>>> use a simple upwind scheme. Thus, these values are obtained from inside
>>>> the domain, which means that this only works well as long as you really
>>>> have a flux leaving the domain. If the sign flips (essentially an inflow
>>>> boundary), mobility and density are not defined.
>>>>
>>>> With respect to your question what the difference is: you could achieve
>>>> the same thing manually by implementing the above mentioned stuff into the
>>>> neumann() function:
>>>> But note that especially for cell-centered schemes the outflow BCs are
>>>> rather tricky to realize and personally I would try to avoid them and
>>>> restrict myself to Neumann and/or Dirichlet BCs where you actually know
>>>> what exactly happens.
>>>>
>>>> Best wishes,
>>>> Dennis
>>>>
>>>>
>>>> Von: Dumux <[email protected]>
>>>> <mailto:[email protected]> im Auftrag von lc
>>>> <[email protected]> <mailto:[email protected]>
>>>> Gesendet: Montag, 3. Dezember 2018 12:37:19
>>>> An: [email protected]
>>>> <mailto:[email protected]>
>>>> Betreff: [DuMuX] on IMPES, grid adaptation and BCs
>>>>
>>>> Hello,
>>>>
>>>> I have the following questions:
>>>>
>>>> 1) Is it possible to run IMPES algorithm in sequential (not implicit)
>>>> mode without considering capillarity forces (pressure)?
>>>>
>>>> 2) Is it possible to do some sort of grid adaptation, for example
>>>> locally refine the (unstructrured) mesh where the water saturation front
>>>> becomes steeper? If yes, how, is there any example?
>>>>
>>>> 3) What actually the Outflow BC does? What is the difference with Neumann?
>>>>
>>>>
>>>> Thank you very much!
>>>>
>>>> Kind regards,
>>>>
>>>> Lorenzo
>>>>
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>>>
>>>
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>> --
>> *******************************************************
>>
>> Beatrix Becker
>>
>> Department of Hydromechanics and Modelling of Hydrosystems (LH2)
>> Institute for Modelling Hydraulic and Environmental Systems (IWS),
>> University of Stuttgart
>> www.hydrosys.uni-stuttgart.de <http://www.hydrosys.uni-stuttgart.de/>
>> email: [email protected]
>> <mailto:[email protected]>
>> Pfaffenwaldring 61
>> 70569 Stuttgart
>> Tel.: ++49 711 / 685-60500
>>
>>
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