Current state of generic data exchange in volume coupling of OpenFOAM adapter

Official adapters and tutorials
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1

Hello everyone!

Intro

I am starting to use the preCICE-adapter to couple an in-house DEM solver with OpenFOAM. I am on the current develop branch of openfoam-adapter, precice v3.2.0 and am using openfoam2412 and Fedora41. Starting point is this paper: ORBilu: Detailed Reference and the preCICE-Tutorials.

Generic data exchange in volume-coupling

From what I saw in the forums and the documentation, a generic data exchange is currently not supported:

And it was discussed that there is being done some work on it currently:

I wanted to inform myself if there is any active development done here or if there is information about the current state.

My use case

My current approach will be misusing the velocity-read of the OpenFOAM-adapter to pass the momentum-sourceterm from DEM->CFD (could also be just passing the void-fraction of each cell - I did not find out what the most convenient way is yet). Unidirectional coupling from CFD->DEM seems to work without an issue.

out
out1431×220 36.3 KB

The issue I am currently facing appears when trying to implement bidirectional coupling. I am not sure if I can read and write to different velocity fields e.g. something like this:

modules (FF);

interfaces
{
  Interface1
  {
    mesh               FluidMesh;
    patches            ();
    cellSets           (meshBox);
    locations          volumeCenters;
    
    readData (Velocity0);
    writeData (Velocity1);
  };
};

FF
{
  nameVelocity0     U_vol;
  nameVelocity1     U;
};

Is bidirectional volume-coupling supported? I guess misusing the velocity-field for sourceterm exchange is not exactly the “preCICE” way of doing this but it’s my first naive approach. I should mention that I have zero experience with CFD and OpenFOAM but am motivated to work on this :sweat_smile:

I am willing to take a look into #279 and might be able to contribute some form of generic data-exchange to it. Any input regarding the state of issue or just something about preCICE CFD-DEM coupling is highly welcomed.

Thanks a lot!

2

UPDATE:
After diving a little deeper into the OpenFOAM adapter and its source code I understood the modularity and extensibility of the adapter. I created a module and defined a VolumePorosity field to exchange from my solver to OpenFOAM.

config
config685×484 57.9 KB

EDIT:
The current preciceDict looks something like this:

modules (MOM FF);
interfaces
{
  Interface1
  {
    mesh               FluidMesh;
    patches            ();
    faceSets           (couplingFaces);
    locations          volumeCenters;
    
    readData
    (      
    );
    
    writeData
    (
      Velocity
    );
  };

  Interface2
  {
    mesh               FluidMesh;
    patches            ();
    cellSets           (meshBox);
    locations          volumeCenters;
    
    readData
    (
      VolumePorosity
    );
    
    writeData  ();
  }
};


MOM
{
  nameVolumePorosity     VolumePorosity;
};

EDIT:
I can now exchange generic data bidirectional but am still facing an issue - I seem to receive sparse data (random 0 entries) from the OpenFOAM adapter (data is not sparse in OpenFOAM but after I receive it in my solver) and am currently trying to find out the reason for that. I would be interested in talking to someone that is actively using bidirectional communication (of generic data) with the OpenFOAM adaper about topics like performance, scalability and maybe some lessons learned :slight_smile:

1 Like