Domain imbalance and convergence
 

I am modelling gas-solids interaction using a rectangular box. My solid inlet is at the top of the box. The gas inlet & outlet were modelled as opening boundary condtion. There was not boundary condition for the solid flow out the sytem. After running the simulation, i experienced a domain imbalance(70%) for the mass of the solids and negative domain imbalance for the mass of the air. I had convergence @ residual 1E-04. I reduced the residual to 1E-05 so as to have achieve domain imbalance with the recommended value(0.01%) but this does not converge again.

I took further steps by defining a solid outlet boundary conditon and the domain imbalances for the masses of solid and air were negatives.


Does domain imbalance matter though? or Is it because of the particular case study that the solid is not flowing out

Look forward to your reply

Which approach for the solid?