Hi @DaleKramer: I did not know there are any edit limits: hope it is solved for you…
From observation of small BMB (velocity vectors or particle traces) I see that those BC defined as Zero Gradient are ‘leaking’, so air or water will travel the BC in both directions. This is pressure-wise as kind of surface tension prevents complete fluid evacuation. In any case, most of fluid will still be evacuated by Pressure outlet.
As we do not have programme insight into Zero Gradient BC, this is just the ‘intuition’. May be somebody from inner circle will help to understand the real nature of Zero Gradient BC.
I’ve seen iso surface or iso volume shaping in a way ‘coherent’ to space filled with that medium. I repeat that the space outside the BMB seems filled with medium and not being void. So it is implicit and subjective impression…
I think I will investigate by placing ZeroGradient walls close to an object such that it would send air out to bump into that ‘force’ field and consequentially, it would also would try to suck that force field inwards, downstream.
Then look at the velocity vectors from that ZeroGradient setup and compare them at the same location, from the same object, in a VERY large BMB with slip walls…
I cannot work today with Simscale: “Connection to server interrupted: Attempting to reconnect…” message is coming for a while, so I would not produce any example. It may be also linked to Internet traffic here. So far, so bad.
@DaleKramer@Retsam@jousefm
My problem solved. It is solved by changing the MRF size. There must be some clearance between the MRF zone and the turbine’s blade.
@DaleKramer: I have small example of Zero Gradient BC, making my tunnel in a project started two days ago in order to validate TET mesh for CFD. I’m also testing your ‘numerics’ which could save time and core-hours. But for the moment look at that:
It may be also linked to Internet traffic here. So far, so bad.
Give me 5 minutes (sorry for the delayed reponse by the way) 