Help modelling a 2D open channel
 

Hi,

I'm new using fluent. I'm trying to model a 2D (top view) open channel flow, a water tank, with an actuator disk in the middle of the cross section, see Fig.-1, in order to evaluate de horizontal components of velocity. The tank is y=1.37m, x=5m, the actuator disk (with edge geometry) is y=0.1m.


I set up the model with the following boundary conditions for every edge:

• Inlet: inlet velocity.
• Outlet: pressure outlet.
• Side walls: walls.
• Actuator disk: porous jump. Porous medium thickness = 0.001m, pressure jump coef. = 0.5/m (I tried higher values but the results didn't change) and face permeability = default value 1e10m².
• The edges next to the actuator are set as interior.

The problem is that the result doesn't show any variations in the velocity components due to the interaction with the actuator disk, see Fig.-2.

Any suggestions?

Thank you!

http://img843.imageshack.us/img843/2856/tanque7.png
Fig.-1 - Tank mesh, actuator disk in red.

http://img585.imageshack.us/img585/8607/tanque6.png
Fig.-2 - Velocity magnitude results.

Hi,
first, you have open channel flow and phase changes occur in normal direction(z).
2D modeling is acceptable if actuator locate near free surface I think.
second, setting outlet as outflow may work.