[Gerrit]

Hello,

I am sorry that I did not respond for such a long time, but I had to hand in my project.
However, you are right: I use the steady state version so it is actually not the time, but the number of loop iterations.

Do you copy the internal field into your newly created fields at the end of each simple loop step or just when you create the fields?

What do you mean with thisexactly?
What I did was simply to copy paste an old case, solved with buoyantSimpleFoam, change the solver in the controlDict and run it with mybuoyantSimpleFoam.
In case of having an already solved filed from the buoyantSimpleFoam solver at loop number 300 e.g. my new solver saves fields for everything I want.
But if I start a simulation based on the boundary conditions from the 0 folder, I do not get fields, only a file containing a value at the boundary. Like this for the viscosity:

dimensions      [1 -1 -1 0 0 0 0];

internalField   uniform 1.01224393412375e-05;

boundaryField
{
    inlet
    {
        type            calculated;
        value           uniform 1.01224393412375e-05;
    }
    outlet
    {
        type            calculated;
        value           uniform 1.01224393412375e-05;
    }
    wall1
    {
        type            calculated;
        value           uniform 1.01224393412375e-05;
    }
    wall2
    {
        type            calculated;
        value           uniform 1.01224393412375e-05;
    }
    wire-upstream
    {
        type            calculated;
        value           uniform 1.29521557667375e-05;
    }
    wire-north
    {
        type            calculated;
        value           uniform 1.29521557667375e-05;
    }
    wire-south
    {
        type            calculated;
        value           uniform 1.29521557667375e-05;
    }
    wire-downstream
    {
        type            calculated;
        value           uniform 1.29521557667375e-05;
    }
    top
    {
        type            empty;
    }
    bottom
    {
        type            empty;
    }
}

Best
Gerrit