[umair64]

how set boundary conditions for opening type out....
i want to use the opening type outlet just to avoid the following warning msg,,,, please guide me.....
****** Notice ****** |
| A wall has been placed at portion(s) of an OUTLET |
| boundary condition (at 100.0% of the faces, 100.0% of the area) |
| to prevent fluid from flowing into the domain. |
| The boundary condition name is: Outlet. |
| The fluid name is: vapourWater. |
| If this situation persists, consider switching |
| to an Opening type boundary condition instead.

[ghorrocks]

FAQ: http://www.cfd-online.com/Wiki/Ansys...f_an_OUTLET.22

[Steffen595]

If 100% of the outlet is set to wall, there may be some other problem. Pressure on outlet too high. Or something else. Check massflows on inlet vs outlet and check the streamlines in postprocessor

[ghorrocks]

Hi Steffen

This is a very frequently asked question, so we should have a good FAQ which answers the question. The FAQ I linked to describes a few basic details but really needs to cover some more issues. Are you able to update the FAQ page to more fully describe the situation? That would be great if you did. And feel free to make some updates to other sections on the FAQ while you are at it.

[Steffen595]

last time is a while ago, just don't want to put in wrong information.
check the streamlines, if there are insane eddies, you know, there is trouble.
What is happening at the inlet, walls as well?
Is there more than 1 outlet?
What is inlet condition, domain pressure, inlet pressure?
Maybe the outlet is blocked by some geometry?
Can you post some images?

[ghorrocks]

Don't be afraid to update the FAQ wiki page. Several people are watchers on it so updates will get reviewed soon enough. I don't have time to do it all myself so it would be great if some others who have some experience help keep the FAQ page current.

Note: The FAQ page requires its own login to edit it. The forum login will not work.

[Steffen595]

meanwhile some nice reading:

http://www.arc.vt.edu/ansys_help/cfx_mod/i5500692.html

[umair64]

i have replaced the outlet with opening.... means change to opening from outlet.... now i am not facing the that warning problem.... i am running the process in transient that is still in progress... what you say will it effect the results....?

[ghorrocks]

Yes, it will affect the results. Make sure you are aware of the differences between outlets and openings and when you should use them. The CFX documentation has a good description of this.

[Steffen595]

opening lets fluid enter the domain as well. If you don't know what happens pressure wise, there is also entrainment.
Are you doing multiphase?

[umair64]

yes i m doing multiphase... boiling of water,,, after its completion i have to deal with boiling of mixture of nitric acid and water