Cyclone with Lots of Porous Jumps = Divergence
 

Hi,

I have a problem that contains a cyclone geom. and has lots of porous jumps in the center.

I meshed the entire geometry with hexa mesh and I ended up with a good quality mesh, only some complex sections of the geometry has tetrahedra mesh.

I solve the problem using Reynold Stress Model, without porous jumps, but when I set the porous jumps and set the constant values for it and run calculation after 50 iteration solver become diverged. :confused: What I am doing wrong?

what do you mean porous jump?
I worked on a cyclone with RSM turbulence model. It's somehow difficult to get a good converged solution, but don't know anything about porous jump? Why is it used for? Maybe you need to start with a simpler turbulence model such as k-e then, after a few iterations go to RSM. Even, you need to start an unsteady simulation. Anyway, I'll be glad to hear about porous jump. thank you

Porous jump is a boundry condution that can be used for any adjacent walls, porous jump is 1D solution equvalent of 3D porous zone.

Are you sure you have put the right permeability and C2 values for porous jump? Also, any specific reason for RSM model?

I have so far observed that Realizable model works best with the porous jumps, amongst all other 2-equation turbulence models. Perhaps, if you really want RSM, you can start with realizable model, have a decent convergence, and then switch to RSM.

OJ