Tutorial on Fluidized Bed has convergence issues
 

Dear all,

I am new to Star CCM+ (v. 8.02). I worked on many tutorials to finally end to the one I need most, the fluidized bed (Eulerian: Bubble Formation in a Fluidized Bed).
The problem with this tutorial is the residuals monitor. It is simply bad as you can see from the attachement. I know that residuals might be bad and I should see other monitors, but I don't know why x and y momentum should be that bad.
The major problem of this bad convergence issue is that when I try to repeat the simulation for a 3D geometry it simply diverges and no solution comes out.

I need to simulate a 3D fluidizied bed similar to the tutorial one (but with full surface bottom air inlet) and I am stucked with convergence issues.

Do you have any help for me, suggestion, books, links, whatever you think can help me to tackle the problem?

Thank you,
Luca