[drait]

Hi,

I am getting this error while running a turbo machine case (periodic model).

Notice: The maximum Mach number is 2.828E+01


****** Notice ****** |
| A wall has been placed at portion(s) of an OUTLET |
| boundary condition (at 17.6% of the faces, 8.9% of the area) |
| to prevent fluid from flowing into the domain. |
| The boundary condition name is: R1 Outlet. |
| The fluid name is: Air Ideal Gas. |
| If this situation persists, consider switching |
| to an Opening type boundary condition instead. |
+------------------------------------------------------

Please help how to overcome this issue.
Thanks in advance

[leasken]

Originally Posted by drait

Hi,

I am getting this error while running a turbo machine case (periodic model).

Notice: The maximum Mach number is 2.828E+01


****** Notice ****** |
| A wall has been placed at portion(s) of an OUTLET |
| boundary condition (at 17.6% of the faces, 8.9% of the area) |
| to prevent fluid from flowing into the domain. |
| The boundary condition name is: R1 Outlet. |
| The fluid name is: Air Ideal Gas. |
| If this situation persists, consider switching |
| to an Opening type boundary condition instead. |
+------------------------------------------------------

Please help how to overcome this issue.
Thanks in advance

It indicates that you have reversed flow over your outlet boundary. You have prescribed the flow to only be out of the domain, the OUTLET boundary condition, and the solver is suggesting that you use an OPENING boundary condition to allow for flow going either out or in of the domain at the outlet.

I usually encounter this problem when I have made my domain too short, not allowing the flow to be stabilized before the outlet. Maybe you can try to make the domain longer, allowing for the flow to "calm" down before it exits the domain.

[turbo]

If you get the message at the early iterations from a false initial, it could go away. If not, your operating condition would be out of or close to the limit of the machine ranges, depending on the type of turbomachines.

[ghorrocks]

This question is a FAQ: http://www.cfd-online.com/Wiki/Ansys...f_an_OUTLET.22