[Erfan-s]

Hello
I am simulating flow in an open channel, when I use outflow boundary conditions at the outlet boundary, the water depth increases, how can I keep it constant?

[koful]

Hi.

What is your inlet BC?

[Erfan-s]

Hi dear koful
Inlet is volume flow rate or specified velocity, with 0.12 cm height

[koful]

If you want a downstream control, choose specified pressure with a specific fluid elevation. If you want an upstream control, you should select outflow bc. So your inlet elevation is 0.12m. How high does the water level rise at the outlet?

[Erfan-s]

Thank you

It reaches 0.15 cm and the flow does not reach equilibrium, but when I take a specific pressure with a height of 0.12 cm, the flow reaches equilibrium and the height of the flow is also 0.12 cm.

[kylas]

Attachment 100188

Originally Posted by koful

If you want a downstream control, choose specified pressure with a specific fluid elevation. If you want an upstream control, you should select outflow bc. So your inlet elevation is 0.12m. How high does the water level rise at the outlet?

Hello! I have a similar problem.
I used a pressure with specific fluid elevation as BC on the upstream side, I want to get a consistent water elevation to flow through the channel but the water level decreases as it approaches the channel. The BC between the reservoir and channel is symmetry. What should I do to maintain the water elevation in the inlet of the channel?