continuity residual convergence problem
 

Hi,

I'm modelling a bouyancy driven natural convection case. When I start iterating, after a few timesteps the continuity residual drops to a more or less constant value above the convergence criteria and the solution no longer converge.

I've tried adjusting the URF, refining the mesh, reducing the timesteps and modelling in 2ddp instead of 2d.

What should I do to overcome this problem?

Regards Cdx