initialize open channel flow with a know water surface profile

Ema40 · February 20, 2016, 10:46

Hello.

I am simulating a simple open channel flow and I succeeded in it.
However there is a thing that I cannot do.

I would like to initialize the solution with a know water surface. The profile has to be linear, and connect the water surface at the inlet with that at the outlet, whose values are imposed in the boundary conditions. I tried in different ways, but the only thing that I can do is to create an horizontal water surface, starting or from the inlet or from the outlet. But I want a non-horizontal water surface, connecting the two known water depths.

Thank you for your help
Regards

seyedashraf · February 20, 2016, 16:59

Try the "Region" option.
use the min and max values
mark the region
use the Patch option

Ema40 · February 21, 2016, 05:11

Thank you.
But in this way I can create an horizontal profile, since the region that I make can be only a parallelepiped. I do not want nor a horizontal water surface, neither a water surface parallel to the bed slope.

Thank you

seyedashraf · February 21, 2016, 06:07

In this way you may have a water surface with a defined slope (min Z and max Z values), yet in the case you need to have a parabolic surface, use your per-processor and define two zones. One showing the air zone, the other one maybe the water zone.
Patch them both in fluent for the secondary fluid, with 0 and 1 respectively.

good luck

Ema40 · February 21, 2016, 12:31

Thank you.
I well understand your second option.
Concerning the first, where you say to me to impose Zmin and Zmax. Zmin should be the minimum Z of the domain patched with water, thus the minimum Z belongs the the bed of the channel, not to the water surface. Do I well understand?

Thank you for your useful help!

February 20, 2016, 10:46	initialize open channel flow with a know water surface profile	#1
Ema40 Senior Member Join Date: Oct 2014 Posts: 124 Rep Power: 12	Hello. I am simulating a simple open channel flow and I succeeded in it. However there is a thing that I cannot do. I would like to initialize the solution with a know water surface. The profile has to be linear, and connect the water surface at the inlet with that at the outlet, whose values are imposed in the boundary conditions. I tried in different ways, but the only thing that I can do is to create an horizontal water surface, starting or from the inlet or from the outlet. But I want a non-horizontal water surface, connecting the two known water depths. Thank you for your help Regards

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February 20, 2016, 16:59		#2
seyedashraf Member Omid Seyedashraf Join Date: May 2010 Posts: 49 Rep Power: 16	Try the "Region" option. use the min and max values mark the region use the Patch option

February 21, 2016, 05:11		#3
Ema40 Senior Member Join Date: Oct 2014 Posts: 124 Rep Power: 12	Thank you. But in this way I can create an horizontal profile, since the region that I make can be only a parallelepiped. I do not want nor a horizontal water surface, neither a water surface parallel to the bed slope. Thank you

February 21, 2016, 06:07		#4
seyedashraf Member Omid Seyedashraf Join Date: May 2010 Posts: 49 Rep Power: 16	In this way you may have a water surface with a defined slope (min Z and max Z values), yet in the case you need to have a parabolic surface, use your per-processor and define two zones. One showing the air zone, the other one maybe the water zone. Patch them both in fluent for the secondary fluid, with 0 and 1 respectively. good luck

February 21, 2016, 12:31		#5
Ema40 Senior Member Join Date: Oct 2014 Posts: 124 Rep Power: 12	Thank you. I well understand your second option. Concerning the first, where you say to me to impose Zmin and Zmax. Zmin should be the minimum Z of the domain patched with water, thus the minimum Z belongs the the bed of the channel, not to the water surface. Do I well understand? Thank you for your useful help!