CFD Online Discussion Forums - Rp() , Ru() in fvdom files

I have tried to check the codes of fvdom.C
(src/thermophysicalModels/radiation/radiationModels/fvDOM)

I found this codes. But I don't know why Rp(),Ru() declares in fvdom.C

Code:

Foam::tmp<Foam::volScalarField> Foam::radiation::fvDOM::Rp() const

{

    return tmp<volScalarField>

    (

        new volScalarField

        (

            IOobject

            (

                "Rp",

                mesh_.time().timeName(),

                mesh_,

                IOobject::NO_READ,

                IOobject::NO_WRITE,

                false

            ),

            // Only include continuous phase emission

            4*absorptionEmission_->aCont()*physicoChemical::sigma

        )

    );

}





Foam::tmp<Foam::DimensionedField<Foam::scalar, Foam::volMesh>>

Foam::radiation::fvDOM::Ru() const

{



    const volScalarField::Internal& G =

        G_();



    const volScalarField::Internal E =

        absorptionEmission_->ECont()()();



    // Only include continuous phase absorption

    const volScalarField::Internal a =

        absorptionEmission_->aCont()()();



    return a*G - E;

}

Why Rp(), Ru() is necessary in fvdom.C??:confused::confused: