Hi, I simulate natural convection in solar chimney (3d) in ansys fluent. I have quad map mesh, aspect ratio is 15 and orthogonal quality is 1.                                                     Boundary condition for inlet is pressure inlet and for outlet is pressure outlet. After running energy , momontum and k and epsilon converged, and the parameter of outlet like temp and velocity become constant, but continuity residual is 10^_3 and it does not come below it and continuity did not converge.

Why and how can I solve this problem?