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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:

            type            DESModelRegions;
            functionObjectLibs ("");
            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:

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

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

    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: - post #10

Best regards,

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:
does not provide an answer for OF30X.

I would be happy to hear your ideas!

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

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