[anon_q]

Hello
In my simulation, I need to add a rotating source term to momentum equations without modifying the code of the solver.
Is it possible to use a rotating source term in fvOptions (has a distance R from the origin rotates about the origin (0,0,0) as a function of time and with given angular velocity)?
Please, can you give me an example?

PS: Without using MRF or Dynamic mesh.

[C. Okubo]

Hi!

I am trying to do this also, but still not successful. Even though, SRFSimpleFoam is not an option for you?

Okubo

[C. Okubo]

Tried some variations of the code below (in .../constant/fvOptions), but it is still not working well...

As far as I understand, this implements a explicit source...maybe, it should be implicit to work (like SRFSimpleFoam)?

Hope somebody can help...

/*--------------------------------*- C++ -*----------------------------------*\
| =========                 |                                                 |
| \\      /  F ield         | OpenFOAM: The Open Source CFD Toolbox           |
|  \\    /   O peration     | Version:  v1806                                 |
|   \\  /    A nd           | Web:      www.OpenFOAM.com                      |
|    \\/     M anipulation  |                                                 |
\*---------------------------------------------------------------------------*/
FoamFile
{
    version     2.0;
    format      ascii;
    class       dictionary;
    location    "constant";
    object      fvOptions;
}
// * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //
velocitySource
{
    type            vectorCodedSource;

    vectorCodedSourceCoeffs
    {
        selectionMode   all;

        fields          (U);
        name            vectorSource;

        codeInclude
        #{

        #};

        codeCorrect
        #{
            Pout<< "**codeCorrect**" << endl;
        #};

        codeAddSup
        #{
	    vectorField& Usource = eqn.source();
            vector rotation = vector(0, 1, 0); // rotation in rad/s

	    const vectorField& radius = mesh_.C(); // center of cells (axis is considered passing through origin)
	    const vectorField& U_ = mesh().lookupObject<volVectorField>("U");

            Usource =  - (rotation^(rotation^radius)) - 2.0*(rotation^U_);
        #};

        codeSetValue
        #{
            Pout<< "**codeSetValue**" << endl;
        #};

        // Dummy entry. Make dependent on above to trigger recompilation
        code
        #{
            $codeInclude
            $codeCorrect
            $codeAddSup
            $codeSetValue
        #};
    }
}// ************************************************************************* //

[ozi]

Did you get any progress with your code. I am struggling with the same issue. Code is working but the solution blows up very quick because of the large numbers produced by the additional source term.

Originally Posted by C. Okubo

Tried some variations of the code below (in .../constant/fvOptions), but it is still not working well...

As far as I understand, this implements a explicit source...maybe, it should be implicit to work (like SRFSimpleFoam)?

Hope somebody can help...

/*--------------------------------*- C++ -*----------------------------------*\
| =========                 |                                                 |
| \\      /  F ield         | OpenFOAM: The Open Source CFD Toolbox           |
|  \\    /   O peration     | Version:  v1806                                 |
|   \\  /    A nd           | Web:      www.OpenFOAM.com                      |
|    \\/     M anipulation  |                                                 |
\*---------------------------------------------------------------------------*/
FoamFile
{
    version     2.0;
    format      ascii;
    class       dictionary;
    location    "constant";
    object      fvOptions;
}
// * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //
velocitySource
{
    type            vectorCodedSource;

    vectorCodedSourceCoeffs
    {
        selectionMode   all;

        fields          (U);
        name            vectorSource;

        codeInclude
        #{

        #};

        codeCorrect
        #{
            Pout<< "**codeCorrect**" << endl;
        #};

        codeAddSup
        #{
        vectorField& Usource = eqn.source();
            vector rotation = vector(0, 1, 0); // rotation in rad/s

        const vectorField& radius = mesh_.C(); // center of cells (axis is considered passing through origin)
        const vectorField& U_ = mesh().lookupObject<volVectorField>("U");

            Usource =  - (rotation^(rotation^radius)) - 2.0*(rotation^U_);
        #};

        codeSetValue
        #{
            Pout<< "**codeSetValue**" << endl;
        #};

        // Dummy entry. Make dependent on above to trigger recompilation
        code
        #{
            $codeInclude
            $codeCorrect
            $codeAddSup
            $codeSetValue
        #};
    }
}// ************************************************************************* //