[robin781105]

Dear Expert:

I try to simulate a channel that the upstream is a steady inflow and downstream is outflow condition.

Is that possible to have an uniform flow through this channel? My free surface drops down from upstream to downstream...

Hope someone can help me, thanks

[sycst911]

Originally Posted by robin781105

Dear Expert:

I try to simulate a channel that the upstream is a steady inflow and downstream is outflow condition.

Is that possible to have an uniform flow through this channel? My free surface drops down from upstream to downstream...

Hope someone can help me, thanks

Uniform as in constant in flow depth (wrt to space)?

Easy, set the fluid elevation to the desired value you want (1m, 100m, etc). Then, it will not fluctuate along the channel.

p/s: I am not expert. Cheers!

[robin781105]

But I've set the channel with a roughness and there is no slope for the channel.
The water surface just like this

[sycst911]

Try setting your fluid elevation like this (e.g. Zmax=0.2m)

[robin781105]

You mean to set an initial fluid? But that's not a real fluid phenomena...

[Chesterton]

To have flow from left to right you need some head difference (water surface slope)

Apply a pressure boundary to the downstream end of the channel. The depth at the downstream boundary will be = the upstream fluid level - the friction slope * channel length.

If the flow is not uniform you will need to adjust the channel roughness.