Spouted bed boundary region definition

Excuse me. I have some difficulties defining the bevel as the wall. I tried filtering facets based on normals. However, I do not know how to make it work. Could you please do me a favor? Thank you very much.

Looking at your image, there is no geometry listed in the geometry pool… Why didn’t you use the case I already started for you: How can I build a spouted bed structure? - #11 by onlyjus Also, try toggling slice facets (sometimes VTK fails) and make sure that facets are actually selected by making sure number of selected facets is > 0

Thank you very much. I used your case and made some changes for the gemometry parameters, which are for the bed I need. Sorry for the trouble I made. I am a rookie and still unfamiliar with some details. Also I am trying to figure out how to fill particles in the geometry by STL. However, I failed. Here is my geometry. Could you please help me check it at your convenience? Thank you very much for your help.
spout.mfx (11.9 KB)

What do you mean by

You can’t use a STL as an initial condition.

Thank you very much. I mean that I want to define the region for bed. But I failed.

I played with the case you attached and got it working. Couple items:

  1. The trick with cut-cell in MFiX is to extend the geometry past the simulation domain to get clean slices and use the normal boundary conditions
  2. To add a bed of particles, simply use the bed region when creating an IC. Then set the volume fraction of the solids to something that is not 0 (i.e. 0.4).
  3. For the inlet BC, you set the velocity of the solids, not the gas. I assume you wanted to set the gas velocity?
  4. Why are you trying to select the cone?

See: spout.mfx (14.4 KB)

Thank you so much. Previously, I was not very familiar with the related details. After your interpretation, I gradually understand them. I made some mistakes. I wanted to set the gas velocity, not the solid velocity. Before, whent I want to define the bed region, I thought I should select the actual geometry shape of the bed. Moreover, I do not know about cut-cell method. So I was trying to select the cone. Now I get a better understanding of it. Thank you very much for your patience and help.

I have one more question. How can I determine the number of samples?

The samples are just discretizing the implicit functions (i.e. converting them from mathematical expressions to triangles). So I just play with the samples until the geometry “looks good”. Note: this is not the fluid grid, that is set on the “mesh” pane.

OK. Got it. Thank you very much.

I was curious so I ran it with PIC

spout_pic.mfx (15.3 KB)

Wow. Thank you very much. When using the STL geometry, why cannot the defaul Johnson-Jackson BC be used? I am confused. And how can I export a video like the one that you showed to me? Thank you very much.

Please search the forum: Johnson-Jackson boundary condition with cut-cell

OK. Got it. Thank you very much. Now I am trying to export the video of the simulation. How can I make it?

Can I ask you a question about the selected facets? In the Regions pane, the selected facets of *stl is also zero but the case can still run. Should I have to make the selected facets>0? I really appreciate your help!

I read the VTK files in paraview and export videos for there

OK. Thank you very much.

Ideally the selected facets > 0. I assume the MFiX sees no facets in the geometry_####.stl file and falls back on the geometry.stl file?

You can save image stacks from the GUI using the option in the toolbar on the right side of the VTK tab. Once you have an image stack, you can use various tools to convert the image stack to a video file, like ffmpeg.

OK. Got it. Thank you very much.