BUG: turbulenceFields: Local omega funcs are unused

Summary

• turbulenceFields.C#L185-188

                case cfOmega:
                {
                    processField<scalar>(f, omega(model));
                    break;
                }

calls the omega of turbulenceFields rather than model.omega().

• Another issue is that using simulationType laminar;, albeit unrealistic, unforgivingly throws fatal error - ceasing simulation.

• Also, the nuTilda expression of turbulenceFields is incorrect. nuTilda is not equal to k/omega:

template<class Model>
Foam::tmp<Foam::volScalarField>
Foam::functionObjects::turbulenceFields::nuTilda
(
    const Model& model
) const
{
    return tmp<volScalarField>::New
    (
        "nuTilda.tmp",
        model.k()/omega(model)
    );
}

Environment information

    base1    = develop
    api      = 2106
    patch    = 0
    HEAD     = 3825c4ee95
    version  = com
    compiler = Clang (system)
             = clang version 9.0.1 
    mpi      = SYSTEMOPENMPI
             = mpirun (Open MPI) 1.10.7.0.5e373bf1fd
    OS       = Description:     openSUSE Leap 15.1
    opts     = linux64ClangDPInt32Opt