[ammarali311]

Hello.
I am working on a simple turbulent flow simulation in a long pipe of length 1m in ANSYS Fluent. The inlet Re is 12000 and inlet velocity is 0.76 m/s. The problem is that the continuity residuals after some iterations remain constant and do not decrease no matter how long you run the iterations. Other residuals decrease and eventually reach the tolerance criteria except the continuity. I have tried changing the viscous model, solution methods, relaxation factors but the continuity residuals never converge .....I am stuck in this loop for a whole month now and don't know what to do....Its only a simple straightforward simulation and i am so much confused ...Please can anyone help me about what am i doing wrong and what solution approach should i use?????

[LuckyTran]

It's probably fine. The continuity residual is scaled differently. If you reset the residuals and keep running the simulation, you'll find that the continuity residual will be stuck at 1.

[duri]

Continuity residual is normalized and dropped by two order which may be fine. May be absolute continuity residual is too small from beginning. Don't normalize or scale the residual and check. Other way of confirming the continuity convergence is through mass flux balance.

[ammarali311]

Thankyou for your replies...I will look into your suggestions