[zbtlfd]

Dear All,

I've been trying to implement a new volScalarField for the kinematic viscosity into the Herschel-Bulkley viscosity model. So far I've tried a few versions of initialising it and they have compiled without errors. However, the solver always crashes, when the "calcNu()" function tries to return the newly implemented viscosity field without even manipulating it (just as a test case for now). The error message is always as follows:

// * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //
Create time

Create mesh for time = 0

Reading field p

Reading field U

Reading/calculating face flux field phi

Selecting incompressible transport model HerschelBulkley
test1
#0  Foam::error::printStack(Foam::Ostream&) at ??:?
#1  Foam::sigSegv::sigHandler(int) at ??:?
#2  
 at sigaction.c:?
#3  Foam::List<double>::List(Foam::List<double> const&) at ??:?
#4  Foam::GeometricField<double, Foam::fvPatchField, Foam::volMesh>::GeometricField(Foam::IOobject const&, Foam::GeometricField<double, Foam::fvPatchField, Foam::volMesh> const&) at ??:?
#5  Foam::viscosityModels::HerschelBulkley::HerschelBulkley(Foam::word const&, Foam::dictionary const&, Foam::GeometricField<Foam::Vector<double>, Foam::fvPatchField, Foam::volMesh> const&, Foam::GeometricField<double, Foam::fvsPatchField, Foam::surfaceMesh> const&) at ??:?
#6  Foam::viscosityModel::adddictionaryConstructorToTable<Foam::viscosityModels::HerschelBulkley>::New(Foam::word const&, Foam::dictionary const&, Foam::GeometricField<Foam::Vector<double>, Foam::fvPatchField, Foam::volMesh> const&, Foam::GeometricField<double, Foam::fvsPatchField, Foam::surfaceMesh> const&) at ??:?
#7  Foam::viscosityModel::New(Foam::word const&, Foam::dictionary const&, Foam::GeometricField<Foam::Vector<double>, Foam::fvPatchField, Foam::volMesh> const&, Foam::GeometricField<double, Foam::fvsPatchField, Foam::surfaceMesh> const&) at ??:?
#8  Foam::singlePhaseTransportModel::singlePhaseTransportModel(Foam::GeometricField<Foam::Vector<double>, Foam::fvPatchField, Foam::volMesh> const&, Foam::GeometricField<double, Foam::fvsPatchField, Foam::surfaceMesh> const&) at ??:?
#9  
 at ??:?
#10  __libc_start_main at ??:?
#11  
 at ??:?

In the HerschelBulkley.H file, I've declared the new "volScalarField kinVisc":

class HerschelBulkley
:
    public viscosityModel
{
    // Private data

        dictionary HerschelBulkleyCoeffs_;

        dimensionedScalar k_;
        dimensionedScalar n_;
        dimensionedScalar tau0_;
        dimensionedScalar nu0_;

        volScalarField nu_;
        mutable volScalarField kinVisc_;


    // Private Member Functions

        //- Calculate and return the laminar viscosity
        tmp<volScalarField> calcNu() const;

and in the constructor of the HerschelBulkley class it is defined the same as "nu_"

Foam::viscosityModels::HerschelBulkley::HerschelBulkley
(
    const word& name,
    const dictionary& viscosityProperties,
    const volVectorField& U,
    const surfaceScalarField& phi
)
:
    viscosityModel(name, viscosityProperties, U, phi),
    HerschelBulkleyCoeffs_(viscosityProperties.subDict(typeName + "Coeffs")),
    k_(HerschelBulkleyCoeffs_.lookup("k")),
    n_(HerschelBulkleyCoeffs_.lookup("n")),
    tau0_(HerschelBulkleyCoeffs_.lookup("tau0")),
    nu0_(HerschelBulkleyCoeffs_.lookup("nu0")),
    nu_
    (
        IOobject
        (
            name,
            U_.time().timeName(),
            U_.db(),
            IOobject::NO_READ,
            IOobject::AUTO_WRITE
        ),
        calcNu()
    ),
    kinVisc_
    (
        nu_
    )
{}

I've tried alternative ways of defining kinVisc without copying nu_'s properties:

    kinVisc_
    (
        IOobject
        (
            "kinVisc",    //name
            U_.time().timeName(),
            U_.db(),    //U_.mesh(),
            IOobject::NO_READ,
            IOobject::AUTO_WRITE
        ),
        U_.mesh(),
        dimensionedScalar("kinVisc", dimensionSet(0, 2, -1, 0, 0, 0, 0), 0.01)
    //dimensionSet(0, 2, -1, 0, 0, 0, 0)
    )

In the "calcNu()" function it looks like this:

Foam::tmp<Foam::volScalarField>
Foam::viscosityModels::HerschelBulkley::calcNu() const
{
    dimensionedScalar tone("tone", dimTime, 1.0);
    dimensionedScalar rtone("rtone", dimless/dimTime, 1.0);
    tmp<volScalarField> sr(strainRate());

 // return
 // (
 //     min
 //     (
 //         nu0_,
 //         (tau0_ + k_*rtone*(pow(tone*sr(), n_) - pow(tone*tau0_/nu0_, n_)))
 //        /max(sr(), dimensionedScalar("VSMALL", dimless/dimTime, VSMALL))
 //     )
 // );

    /*return
    (
        min
        (
            nu0_,
            (tau0_*(1.0-exp(-m_*tone*sr())) + k_*rtone*pow(tone*sr(), n_))
           /(max(sr(), dimensionedScalar ("VSMALL", dimless/dimTime, VSMALL)))
        )
    );*/


    Info << "test1" << endl;
    /*forAll(U_.mesh().cells(),celli)
    {
        Info << "test2" << celli << endl;
        kinVisc_[celli] = 0.01;
        Info << "test3" << celli << endl;
    }*/  
    return kinVisc_;
}

Though it compiles without errors, the codes crashes when trying to return the kinVisc_ volScalarField.

Declaring kinVisc_ as a tmp<volScalarField> didn't work either.

Could anyone help me out here and tell me how it should be done correctly?

Thank you very much and best regards,

Lukas