It’s a good case you have selected to simulate. Regarding the question of “far field BC” ;
'I was wondering if there is a farfield BC in SimScale? If not I probably just have to choose a distance that is far enough away from my boundary layer so that it is not influencing my boundary layer, right? ’
I would first like to clarify what I interpret as such a BC. As this BC name is commonly used by “fluent” or other tools, they describe it as given by the link:
Far-field boundary condition please read
Then it is provided that " …you must place the far-field boundary far enough from the object of interest…In case on an Airfoil, it is not uncommon for the far-field boundary to be a circle with a radius of 20 chord lengths"
So, by definition a “Far-field” BC is suppose to be ‘far’. The analogous BC in SimScale/OpenFOAM is the Velocity “Freestream BC” . Freestream BC is like a hybrid fixedValue and zeroGradient boundary condition. Similar to the ‘Far-field’ it is generally required to be placed far at free-stream conditions.
Then, I suppose what you require is something like a “Non-Reflective/Wave transmissive” or an “Advective” BC that does not influence the interior domain and can be placed closer.
Is that correct ?