[vienloer]

hello everyone, would you please help me.

I need to calculate and output the "UMean" in the dsmcFoam. But the "UMean" cannot be putout like the "momentumMean". I read the IOobject code, and found that "momentumMean" is in "mesh_" and "UMean" is in "obr_". I do not know the different between "mesh_" and "obr_".

For "momentumMean" the code like:

   IOobject
        (
            this->name() + "momentum_",
            mesh_.time().timeName(),
            mesh_,
            IOobject::NO_READ,
            IOobject::NO_WRITE
        ),
        mesh_,
        dimensionedVector(dimensionSet(1, -2, -1, 0, 0), Zero)

For "UMean" the code like:

  IOobject
            (
                "UMean",
                obr_.time().timeName(),
                obr_,
                IOobject::NO_READ
            ),
            momentumMean/rhoMMean

I want to know the different between "mesh_" and "obr_". And when I use externalCoupled, the "momentumMean" can output, the "UMean" cannot, can you tell me why? Should I use "mesh_" in the "UMean" calculation?

The externalCoupled code like :

externalCoupled
{
    // Mandatory entries
    type            externalCoupled;
    libs            (fieldFunctionObjects);

    // Directory to use for communication
    commsDir        "<case>/comms";

    // Does external process start first
    initByExternal  true;

    regions
    {
        // Region name (wildcards allowed)
        ".*"
        {
            // Patch or patchGroup
            coupleGroup
            {
                // Fields to output in commsDir
                writeFields (UMean, momentumMean);

                // Fields to read from commsDir
                readFields  ();
            }
        }
    }
}

Thank you for your time~