I already tried to reduce the inlet velocity (to values around 0.0005) but without success. Nevertheless I think I figured out why my computation crashes: It comes from the voxalization of my STL pipe which creates something like that:
Mmmm… I don’t know unfortunately I have very little experience in geometries from STL files. However, I work with porous media and I often encounter the situation you described. Sometimes, I have BB nodes which don’t see the fluid nodes at all!
It seems you were right, I made tests with different lattices I do not have BB nodes in from of one another anymore but the computation still crashes… So I try your idea of reducing the velocity and the computation runs smoothly for Reynolds under 160 but crashes for higher Reynolds number…
I open a knew post for this specific problem “Lattice requirement for wall driven flow” with my code.