[DesignModeler] Creating Bottom Layer of Sediment in 2D Sand Trap Model

Nosravi · July 3, 2020, 08:40

Hello!

I am trying to find ways to reduce the flow of sediment into a turbine, and I am therefore trying to simulate how a layer of sand behaves in the sand trap upstream of the penstock.

The simulation is 2D, and my idea is to use sketching to create a zone from the bottom up to a certain height which i can later initialize as sand in some way. Though I have not figured out how to differentiate this zone from the rest of the geometry when I create surface from geometry.

I have also seen that you can declare horizontal rectangles that will be sand in the setup part, however, the sandtrap I am simulating has a slight incline. Therefore I cannot figure how to declare the bottom as sand in 2D.

I will attatch an imgur folder of pictures of my model.
https://imgur.com/a/dBACAQb

The length of the sand trap is approximately 160m, height 11m, U = 2m/s.
The many small rectangles represent beams installed to try and reduce the water's effects on the sediment.

Any help is appreciated!

Gweher · July 7, 2020, 02:17

Hello Mads,

Well you can simply split your surface in Design Modeller using the frozen/slice options. You can use edges, or planes (with whatever angle you want) to create a slice. The trick at the end is to regroup the different sub-surfaces into a part > select all the surface you need > rmb > form new part.

Have fun

Nosravi · July 8, 2020, 04:54

Thanks for the reply!
I tried slicing the surface, however nothing happens when i press Generate. I get a warning saying that no solid bodies were created from the slice. The guides for using the Slice tool are all for 3D models. Does Slice work for my 2D model?

Gweher · July 9, 2020, 03:31

Hello Mads,

Did you check that your bodies were "frozen" before performing the slicing ? If not you need either when you generate your surfaces to change the option "add material" to "add frozen" or insert a "freeze" and select the surfaces of interest.

The slice option works perfectly also for 2D surfaces. I made a detailed post quite some time (8 years

to be precise) for a U-bend 2D geometry going though the slicing process:

U-bend Mesh in ANSYS

Have fun

Nosravi · July 13, 2020, 05:09

Thanks for the feedback! After reading your detailed guide, I went through my own model, I realized I sliced through a plane that didnt intersect with my model. My mistake, but I learned from it!

Gweher · July 16, 2020, 04:09

Great to hear, and good to see that old posts are useful

July 3, 2020, 08:40	Creating Bottom Layer of Sediment in 2D Sand Trap Model	#1
Nosravi New Member Mads Ivarson Join Date: Jul 2019 Posts: 17 Rep Power: 6	Hello! I am trying to find ways to reduce the flow of sediment into a turbine, and I am therefore trying to simulate how a layer of sand behaves in the sand trap upstream of the penstock. The simulation is 2D, and my idea is to use sketching to create a zone from the bottom up to a certain height which i can later initialize as sand in some way. Though I have not figured out how to differentiate this zone from the rest of the geometry when I create surface from geometry. I have also seen that you can declare horizontal rectangles that will be sand in the setup part, however, the sandtrap I am simulating has a slight incline. Therefore I cannot figure how to declare the bottom as sand in 2D. I will attatch an imgur folder of pictures of my model. https://imgur.com/a/dBACAQb The length of the sand trap is approximately 160m, height 11m, U = 2m/s. The many small rectangles represent beams installed to try and reduce the water's effects on the sediment. Any help is appreciated!

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July 7, 2020, 02:17		#2
Gweher Senior Member Gwenael H. Join Date: Mar 2011 Location: Switzerland Posts: 392 Rep Power: 20	Hello Mads, Well you can simply split your surface in Design Modeller using the frozen/slice options. You can use edges, or planes (with whatever angle you want) to create a slice. The trick at the end is to regroup the different sub-surfaces into a part > select all the surface you need > rmb > form new part. Have fun

July 8, 2020, 04:54		#3
Nosravi New Member Mads Ivarson Join Date: Jul 2019 Posts: 17 Rep Power: 6	Thanks for the reply! I tried slicing the surface, however nothing happens when i press Generate. I get a warning saying that no solid bodies were created from the slice. The guides for using the Slice tool are all for 3D models. Does Slice work for my 2D model?

July 9, 2020, 03:31		#4
Gweher Senior Member Gwenael H. Join Date: Mar 2011 Location: Switzerland Posts: 392 Rep Power: 20	Hello Mads, Did you check that your bodies were "frozen" before performing the slicing ? If not you need either when you generate your surfaces to change the option "add material" to "add frozen" or insert a "freeze" and select the surfaces of interest. The slice option works perfectly also for 2D surfaces. I made a detailed post quite some time (8 years to be precise) for a U-bend 2D geometry going though the slicing process: U-bend Mesh in ANSYS Have fun

July 13, 2020, 05:09		#5
Nosravi New Member Mads Ivarson Join Date: Jul 2019 Posts: 17 Rep Power: 6	Thanks for the feedback! After reading your detailed guide, I went through my own model, I realized I sliced through a plane that didnt intersect with my model. My mistake, but I learned from it!

July 16, 2020, 04:09		#6
Gweher Senior Member Gwenael H. Join Date: Mar 2011 Location: Switzerland Posts: 392 Rep Power: 20	Great to hear, and good to see that old posts are useful