[sisetrun]

Hey Foamers,

I am currently working on a modified kinematicParcel in OF 2.3.

I would like to add a molecular diffusion to the

dt *=  dCorr/d *p.trackToFace(p.position() + dCorr*U_/magU + DIFFUSION), td);

in the KinematicParcel.C at line 305.

Therefore, I want to read a dimension scalar from the transportProperties dict.

Is there a way to read this scalar without the classical way (see below) since I do not want to run createMesh.H everytime the function is called...

In the KinematicParcel.C there is no construction of a mesh/time. The mesh is constructed much later when the solver is called.

    Info << "Reading transportProperties \n" << endl;

    IOdictionary transportProperties
    (
        IOobject
        (
            "transportProperties",
            runTime.constant(),
            mesh,
            IOobject::MUST_READ_IF_MODIFIED,
            IOobject::NO_WRITE
        )
    );


    dimensionedScalar Diffusion
    (
        transportProperties.lookup("Diffusion")
    );

Or in other words, how can I access a dimensioned scalar from a file/dictionary within a class?

Thanks a lot!

Best regards

[Tobi]

Hi,

you have access to registered objects using that line:

volScalarField test = this->db().lookupObject<volScalarField>("myField");

However, I am not sure if you can use that for dimensionedScalars.
What you can do in your library is to build a dictionary and store it. Then you can easily access the lookup functionality of that object and thus you can read the value in the dictionary.

Therefore you have to add that object to the header file and initialize it while calling the constructors. Thats it. The constructor itself should have access to the mesh and time (indirectly). However, I never went into that classes so maybe I am wrong here but the way above is working (but I guess not with dimensionedScalars but you could use an scalarIOList which is available in the database. There you could put your scalar and build a dimensioned scalar in the kinematicParcel.C file. E.g.

createFields.H

scalarIOList myScalar
(
    IOobject
    (
        "myScalar",
        runTime.timeName(),
        mesh,
        IOobject::NO_READ,
        IOobject::NO_WRITE
    ),
    1      // only one entry in the list
);

myScalar[0] = dict.lookup(...);

Then in the kinematicParcel.C file you can get access to that value:

const scalarIOList& tmp = this->db().lookupObject<scalarIOList>("myScalar");

const dimensionedScalar DIFFUSION ("myDimScalar", dimLess, tmp);

// Further calculation

Hope this helps you.
Good luck


By the way. If it is a template class you have to access it differently (for FOAM-4.x)

const scalarIOList& tmp =
    this->db().template lookupBoject<scalarIOList>("myScalar");

[sisetrun]

Once again, thank you Tobias.
I will give it a try...

Have a nice weekend

[sisetrun]

I managed it in a different way...
Just as information if anybody has the same issue:

In the files of kinematicParcel, I added the variable to the constantProperties and adjusted all constructors and member functions.

Now the I am able to use Dmol() (Diffusion) as a function which returns the Dmol from the propertiesDict in the constant folder.

[Tobi]

Yes, of course that is a better way
Finally there are more ways you can handle that. Well done and good to know that it is working.

[uosilos]

I have included this code in my BC

#include "scalarIOList.H"
const fvMesh& mesh_ = this->internalField().mesh();
                 
scalarIOList copyOpenFraction 
    (
        IOobject
        (
            "copyOpenFraction",
            mesh_.time(),
            mesh_,
            IOobject::NO_READ,
            IOobject::NO_WRITE
        ), 1    
    );
copyOpenFraction[0] = openFraction_;

But it shows this error , Any idea??

error: no matching function for call to ‘Foam::IOobject::IOobject(const char [17], const Foam::Time&, const Foam::fvMesh&, Foam::IOobject::readOption, Foam::IOobject::writeOption)’
  357 |   ), 1
      |   ^

[Tobi]

The constructor you are calling does not exist.