Convergence issure with pressure BC
 

Hello folks - I ran to this problem and in order to fix it I simplified my model into a very simple symmetrical cylinder with 10mm dia and 20 mm length. The inlet is pressure-inlet (6e5 Pa) and the outlet is pressure-outlet (1e5 Pa). I use standard k-epsilon. The continuity equation doesn't converge (criterion 1e-3), it steadily fluctuates, see attached image. My mesh quality is good, minimum orthogonal quality = 0.81, max ortho skew = 0.19 and max aspect ratio =3.5 I tried the followings but none worked, 1- realizable k-epsilon, 2- higher order for turbulent kinetic energy and tubulent dissipation rate, 3- URF values for pressure 0.15 and momentum 0.3, 4- using 6000 iterations. Any suggestion would be greatly appreciated.