CFD Online Logo CFD Online URL
Home > Forums > Software User Forums > ANSYS > FLUENT

pressure outlet (open channel flow)

Register Blogs Members List Search Today's Posts Mark Forums Read

LinkBack Thread Tools Search this Thread Display Modes
Old   April 3, 2007, 09:42
Default pressure outlet (open channel flow)
Willem Brantegem
Posts: n/a
My problem: I've got a channel (under: water, above: air). I want to give in: rate at the inlet, water height at the outlet. Fluent has to iterate till convergence. I tried: mass flow inlet: give in: water rate = ... pressure outlet: give in: free surface level = ... (using open channel flow)

My result: I've got water inflow over the whole inlet (but that's not what I want, Fluent has to calculate the water surface from the free surface at the outlet, to the inlet (by means of the rate I defined at the inlet)) And even at the outlet the water surface is not what I want. He doesn't take the free surface level that I defined.

If somebody knows a little part of the solution, or somebody knows a lot of 'open channel flow', please answer this question. My email:

Thank you, Willem.

  Reply With Quote

Old   April 3, 2007, 12:21
Default Re: pressure outlet (open channel flow)
Posts: n/a
Hi Willem,

From your discription od the case it seems the simulation is correct. The water level at an inlet is strongly dependent on the downstream level which you defined not on your inlet level. The upstream level would be adjusted by a hydraulic resistance in the system and the downstream water level. So in your case, you should adjust the downstream water level to close a level which is reasonable in a real situation. Then free level would be reasonably accurate from Fluent simulation.

Hope it would give your some help.

Good luck,


  Reply With Quote

Old   April 4, 2007, 02:40
Default Re: pressure outlet (open channel flow)
Posts: n/a
Hi Mark I am use the open channel flow boundary too. I define the free surface level ,at inlet and I used the boundary pressure inlet and at outlet I used pressure outlet and I told Mr. Wilem by email to did that. Can you tell me to how the downstream water level be adjusted in more deatails.

Regards K. Baker
  Reply With Quote


Thread Tools Search this Thread
Search this Thread:

Advanced Search
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are On
Refbacks are On

Similar Threads
Thread Thread Starter Forum Replies Last Post
boundary conditions in FLUENT VOF for open channel flow newcomer Fluent Multiphase 33 Yesterday 13:41
Boundary condition problem for open channel flow Andy CFX 9 June 11, 2016 07:20
Open Channel Flow Boundary Conditions TWaung STAR-CCM+ 2 October 7, 2011 00:37
Reversed flow at pressure outlet Seeker Phil FLUENT 9 January 2, 2010 05:21
pressure outlet BC for incompressible flow khaiching Main CFD Forum 6 October 15, 2005 02:58

All times are GMT -4. The time now is 16:22.