[ivan-s]

I'm working on a fairly simple plenum with a bunch of tubes attached to it. It's a kind of precipitator.

Flow is turbulent. The plenum is 5m x 8m x 2m, with a couple of hundred 0.1m x 3m tubes coming out of it. The plenum has an inlet perpendicular to the tube bank. Hopefully after I get it to converge I'll begin to add barriers inside the plenum to adjust the flow to the tubes. At this point I'm not even including the outlet plenum in the model.

The thing is very hard to get to converge. I've tried both k-e and k-w models. The maximum size of the elements in the plenum is now 0.02m, so there are well over 10^7 elements.

I'm not sure what to try next to get this to converge. Any advice would be greatly appreciated.

[ivan-s]

I seem to have found a technique, to use the time dependent solver.