[sunilpatil]

Hello,
i am trying to simulate 3D model of fluid flow(velocity=2m/s) over a flat plate(thickness=5mm,length=100mm.width=100mm) while running in CFX solver i am getting following error
****** Notice ****** |
| A wall has been placed at portion(s) of an OUTLET |
| boundary condition (at 3.0% of the faces, 0.1% of the area) |
| to prevent fluid from flowing into the domain. |
| The boundary condition name is: OUTLET. |
| The fluid name is: Fluid 1. |
| If this situation persists, consider switching |
| to an Opening type boundary condition instead.
how to fix this error

[flotus1]

The problem is obvious: there is a backflow at the position of your outlet.
A pressure outlet cannot handle this, so parts of the outlet are treated as a wall. If the warning message vanishes before your computation converges, then you can live with it. Check the results carefully though.

To prevent this error, move the pressure outlet further downstream to a position where no backflow occurs. This provides less uncertainties than using an opening instead of the pressure outlet like the warning message suggests.

[ghorrocks]

This question has been asked so much it is getting very tedious. Alex, do you want to write an FAQ to cover it? (http://www.cfd-online.com/Wiki/Ansys_FAQ)

[flotus1]

Sure, I can give it a try.

Edit: so I finally did it. Sorry for editing my contribution so often

[ghorrocks]

Looks good, thanks.