difference between the opening and outlet ?
 

hi;
What is the difference between the (opening and outlet b.c) in output of open channel?

An opening will allow back flow but an outlet will not.

change the boundary condition opening to outlet
 

hi;
When I change the boundary condition opening to outlet:
****** Notice ****** |
| A wall has been placed at portion(s) of an OUTLET |
| boundary condition (at 62.5% of the faces, 62.4% of the area) |
| to prevent fluid from flowing into the domain. |
| The boundary condition name is: outlet. |
| The fluid name is: water. |
| If this situation persists, consider switching |
| to an Opening type boundary condition instead
Why?what should I do?

as ghorrocks said:
"An opening will allow back flow but an outlet will not". Thats why a wall has been placed by the solver
http://www.arc.vt.edu/ansys_help/cfx_mod/i5500692.html
your outlet/inlet/domain is not properly defined. Check massflow at inlet and outlet, you may have big differences. Maybe one of the pressures is not defined right. Hard to guess without more information

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

if you still struggle, upload some pictures of what you are trying to do

B.c
 

Conditions are correct?

the second one, you dont have to define the walls.
Whats the domain like?
Why bulk mass flow, its not multiphase?
If you do more iterations, will it settle down eventually?
If multiphase, whats the other fluid?

1. in this software by default does not Allocate the wall?
2. Do not we can input discharge to channel in the software?
3. I would be grateful if you explain?
4. The fluid is water!

1. you only have to define inlet and outlet. Walls if not defined are taken as smooth and under same pressure as domain.
4. I have to check, but if its single fluid, its not asking for bulk flow, just mass flow.
2. weird words in weird order. What do you want to say? Is it an open channel, so one half is air? And you put buoyancy in?

http://www.cfd-online.com/Forums/cfx...r-control.html

I see, this is related to this post.

What are you trying to do?
Plus maybe you did not use the dispersed option, then the results get weird as well

B.c
 

Hello
I think the issue is clear.
However. I am an open channel. I model the geometry of the liquid form of water in the canal. It is clearly my question is:
1. are boundary conditions for this problem right?
2. My question is whether the discharge water should be in the software image above I enter?

dont get snappy? Just throwing in a few words and hoping everyone jumps to your rescue with wagging tails is not going to happen.
Anyways its an inlet and an outlet
http://oximaton.drwx.eu/files/ypol_r..._tutorials.pdf
there is a tutorial. This is for Ansys 11. Just search for newer Ansys versions, if you like, but its not much of a difference.
If you install Ansys, there is a help folder as well.
Anyways, tutorial 7 free surface flow over a bump in that .pdf file should answer all your questions