Pr

[jfe293]

Hi!

I am running a stormwater retention pond using single phase approach in Fluent. The total height from free surface to the pond bottom is 3.3050m.
My boundary conditions are given below:
Inlet Pipe: Velocity Inlet
Outlet Pipe: Pressure Outlet with gauge pressure 24320 Pa (hydrostatic pressure: 1000* g *Distance of the centroid of the outlet pipe from free surface h = 2.48m)

Free surface: Zero Shear Wall

Other Walls: No slip

My operating pressure is 101325 pa 

refererence pressure location is X=0 Y=0 and Z=0.

My question is how Ansys is calculating the pressure on free surface based on this condition. As it's an open channel flow simulation pressure on free surface should be zero. But I am getting around 26900 pa.

I know that Fluent always calulates the gauge pressure inside the computational domain using the following formula:
Pabs = Patm (Operating Pressure=101325 pa) + Gauge Pressure

In that sense, I am getting the gauge pressure on free surface as 26900 Pa. But according to the physics of open channel flow there should be zero guge pressure on free surface. So, how could I fix it?

[Richie Mathew]

Hello!

Since this is a duplication of the question, please refer the post (Single Phase Simulation) for solution and further discussions.