CFD Online Discussion Forums

CFD Online Discussion Forums (
-   OpenFOAM Running, Solving & CFD (
-   -   Outlet condition for open channel flow? (

gareth__it_power March 17, 2009 06:44

Outlet condition for open channel flow?
I'm modelling a river with an obstruction in the middle. It's modelled as a simple rectangular channel, using rasInterFoam, OF 1.5.

The inlet is split into two, one of which is the water inlet (v=1m/s) and the upper part is air (0m/s). I set gamma at 1 and 0 respectivly on these inlets, then setFields to set the intitial free surface throughout the domain. A quick look in paraview shows it's all ok at t=0. At the moment there is just one outlet patch, as I don't know where the phase interface will be (slightly lower than that at the inlet I hope!) I have set it as fixedValue pressure, and zeroGradient velocity on this outlet patch, but it produces some very strange results with some problems around the interface (maybe from the compression term applied to the VOF model?)

Is there a more suitable outlet boundary condition? Or is this a more fundamental problem which will require deeper coding? I'm a complete beginner here...

Thank you


msbealo July 17, 2011 03:44

Hi Gareth,

Did you find a solution to this? I'm also interested in the correct inlet/outlet boundary conditions for a channel flow using interFoam.


All times are GMT -4. The time now is 13:29.