[shulnak]

initially ...in my fluent problem ...i made a cuboidal region of interest above the burner exit in my combustion experiment.

1)first,when i used to give top wall pressure outlet and other five walls simply wall b.c ...my residuals were iterating with 3 orders in magnitude ...solution was getting converged..but the domain was constraint because of wall on five sides which i did not want..
2) so i changed all six sides to pressure outlet which is realistic as my burner exit is opened to atmosphere ..but now the solution is not getting converged..

especially the continuity line in scaled residuals ...it just stays above the 3 velocity residuals and fluctuates ....
plz help me and tell where i am wrong