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-   -   How to use DESModelRegions function object (https://www.cfd-online.com/Forums/openfoam-solving/117083-how-use-desmodelregions-function-object.html)

hakonbar May 1, 2013 18:37

How to use DESModelRegions function object
 
Hi! I'm doing some DES simulations, and I would like to see which parts of my flow field are in RANS mode and which are in LES mode. I see the new OF release (2.2.0) introduced a new function object called DESModelRegions, which outputs this data. The thing is, I don't know which lines to put in the controlDict in order to activate this object, and which library to load.

Have any of you used this function object before, and do you know which libs to load etc?

best regards,
Håkon Line

wyldckat May 2, 2013 08:48

Greetings Håkon,

Without an example case, I can't test any further than the following instructions:
  1. Edit the file "system/controlDict".
  2. Append/add the following block:
    Code:

    functions
    {
        desField
        {
            type            DESModelRegions;
            functionObjectLibs ("libutilityFunctionObjects.so");
            log            true;
            //region "region0";
            enabled on;
            storeFilter on;
            timeStart 0.0;
            timeEnd 10.0;
            outputControl timeStep;
            outputInterval      5000;
        }
    }

    Note: it writes and outputs information for each 5000 steps in this example! And if you do not define the "timeStart" and "timeEnd", it will run for the whole simulation.
  3. It created the file "postProcessing/desField/0/DESModelRegions.dat", but I didn't use DES, so I only got this header:
    Code:

    # DES model region coverage (% volume)
    # time  LES    RAS

  4. And since I used "log true;", I only got this message:
    Code:

    DESModelRegions output:
        No DES turbulence model found in database

  5. And it creates the field "DES::LESRegion".
Like I wrote at the beginning, without an example, I can't test this properly.

edit: I do have an example case now and is used here: http://www.cfd-online.com/Forums/ope...tml#post424797 - post #10

Best regards,
Bruno

hakonbar May 3, 2013 08:15

It works perfectly, thanks! Now I've learned the general syntax for function objects as well. =)

potentialFoam July 5, 2016 07:26

Dear Foamers,

can you help me to use 'DESModelRegions' with OF30X?

I fear, it is not implemented in OF30X. But how could you determine the RANS content of a DES?

Using an older version (like OF231) for postprocessing does not work, 'cos the constant/turbulenceProperties-file changed since this version.

Even this thread
HTML Code:

http://www.cfd-online.com/Forums/openfoam-solving/104123-les-content-detached-eddy-simulation-openfoam.html
does not provide an answer for OF30X.

I would be happy to hear your ideas!
Regards,
Peter

EDIT:
According to a hint I installed OpenFOAM-v1606+ from openfoam.com
and this perfectly works for postprocessing cases simulated with OF301 :-)

Bazinga December 2, 2016 04:38

Quote:

Originally Posted by potentialFoam (Post 608048)
Dear Foamers,

can you help me to use 'DESModelRegions' with OF30X?

I fear, it is not implemented in OF30X. But how could you determine the RANS content of a DES?

Using an older version (like OF231) for postprocessing does not work, 'cos the constant/turbulenceProperties-file changed since this version.

Even this thread
HTML Code:

http://www.cfd-online.com/Forums/openfoam-solving/104123-les-content-detached-eddy-simulation-openfoam.html
does not provide an answer for OF30X.

I would be happy to hear your ideas!
Regards,
Peter

EDIT:
According to a hint I installed OpenFOAM-v1606+ from openfoam.com
and this perfectly works for postprocessing cases simulated with OF301 :-)

Dear Peter,

I am also trying to find my LES and RANS regions for my DES simulations. Can you guide me how you used 1606+ to find those regions. Thanks

potentialFoam December 2, 2016 05:01

Sure, inside
system/controlDict.functions
you need to add
Code:

functions
{
 //  Determine LES-content
    desField
    {
      type            DESModelRegions;
      functionObjectLibs ("libutilityFunctionObjects.so");
      log            true;
      enabled on;
      storeFilter on;
      outputControl  outputTime;
    }
}

And afterwards, you can just execute
Code:

execFlowFunctionObjects -time 0.4 | tee log.desField
for the time you want.

Good luck!

Bazinga December 2, 2016 05:09

Quote:

Originally Posted by potentialFoam (Post 627911)
Sure, inside
system/controlDict.functions
you need to add
Code:

functions
{
 //  Determine LES-content
    desField
    {
      type            DESModelRegions;
      functionObjectLibs ("libutilityFunctionObjects.so");
      log            true;
      enabled on;
      storeFilter on;
      outputControl  outputTime;
    }
}

And afterwards, you can just execute
Code:

execFlowFunctionObjects -time 0.4 | tee log.desField
for the time you want.

Good luck!

Thank you so much for the fast reply. Will try it now. Best regards :)

Bazinga December 2, 2016 10:39

Hmmm, I installed v1606+ but it says "execFlowFunctionObjects: command not found".

My OpenFOAM 2.4.0 installation can be used for "execFlowFunctionObjects" but for this the folder and file structure has changed too much since, so it doesn't work.

Anything I am missing here?

wyldckat December 3, 2016 16:18

Quote:

Originally Posted by Bazinga (Post 627970)
Hmmm, I installed v1606+ but it says "execFlowFunctionObjects: command not found".

Quick answer: Something might have went wrong with your installation of v1606+, because execFlowFunctionObjects is built by default in that version as well.

Or maybe you had OpenFOAM 4.0 or 4.1 active in your shell? Because it was replaced by in 4.0 by postProcess, along with (almost) all solvers having their one "-postProcess" argument as well.

Bazinga December 4, 2016 02:55

Thanks for the quick reply. I think something went wrong with the installation. Will try again :)

edit: So, you were right. Not everything was installed during the 1606+ installation. I was able to run wmake for the execFlowFunctionObjects myself and now it is working :)


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