Please include project files - Main menu/Submit bug report - attach zip file here.
dpih_cfddem_2025-10-13T141554.867731.zip (12.0 MB)
Attached is the zipped file.
Thanks and Regards,
Debashis
Please only attach the zip file or the .mfx+.stl . I deleted the .mfx and .stl file.
Are your inlets actually along the xmin and xmax planes?
As I recommended in Solver crashing and issue with Mesh - #5 by cgw use “xmin” and “xmax”, etc instead of numerical values when defining inlets and outlets. Please review that message.
Also there is something wrong with the case you have attached, the “Geometry parameters” panel should not be empty:
I suspect there was a problem loading this STL file.
I don’t know how you got into this state.
Note that deleting the geometry results in a popup error
I fixed the code in the GUI so that it is possible to delete the broken geometry and reload it. When I do that, I see this:
Note that the y dimension is 47 meters. Your STL file is in millimeters.
There seems to be an issue with the “STL file units” control in MFiX, so my suggestion is to rescale the file using trimesh (as suggested in the previous thread):
C> python
>>> import trimesh
mesh = trimesh.load('Aerolizer_1mm_share3.stl')
mesh.apply_scale(0.001)
mesh.export('Aerolizer_scaled.stl', file_type='stl_ascii')
I also found while running your case that the “Description” field is too long and this is causing some runtime errors. Unfortunately the “Description” field is not accessible when in SMS Mesher mode but you can fix this with an editor, or turn off SMS.
For convenience, here’s a copy of your project with the STL file scaled, the Description fixed, and the extents changed to “xmin/xmax”. The “wall” region is now assciated with the STL geometry.
(previously this was “Domain” instead of STL)
Please study these changes and use this fixed version as the basis for future work. Thank you for your patience.
aerolizer-fixed-cgw.zip (23.2 MB)
Dr. Waldman,
Thank you very much.
I will go over this and try to run.
I will try to set up the 2 solids case based on this and I will keep you posted.
Best Regards,
Debashis
Do yo need to resolve the flow inside the internal obstacle? It doesn’t look right, the surfaces are not closed:
You may need a mesh that is finer than the particle size to resolve the flow so it may not be doable with DEM.
Paper-DPI-Capsule-Rotation-Alfano-2022.pdf (4.8 MB)
Aerolizer_1mm_14Oct_device-and-capsule.stl (605.0 KB)
Aerolizer_1mm_share3_capsule_only.stl (414.1 KB)
Dr. Dietikar,
Our ultimate aim is to simulate the case as explained in this attached paper. We plan to replicate this case.
The paper does mention about DEM.
My colleague Dr. Raouf Tajik who is also working in this project created the attached stl files for device and capsule and a combined file (device + capsule) yesterday (see attached).
I think one of our aim will be to resolve flow inside the internal obstacle.
Kindly suggest what other options I have if I cannot use DEM.
Thanks, and Best Regards,
Sincerely,
Debashis
I only quickly glanced at the paper and it looks to me they only looked at the capsule, not the device+capsule. You won’t be able to rotate the capsule and resolve the gas flow accurately in it while it is in the device. To rotate the capsule, you would need to set it as an internal surface, but that will only be seen by the particles, not the fluid itself. In other words, the fluid will go through the capsule walls. The stl internal surface is meant to be used with pure granular flows (no gas phase).
alfano-et-al-2021-full-scale-dem-simulation-of-coupled-fluid-and-dry-coated-particle-flow-in-swirl-based-dry-powder.pdf (6.9 MB)
Thank you for the explanation, Dr. Dietiker. I will discuss this issue with Dr. Raouf Tajik.
I was suspecting this may happen, and you confirm it.
Also, I plan to first simulate this case (attached paper). It is only device and a cup, and I will see this one first (only Carrier particles no capsule).
If everything works, I can go to the capsule case after internal discussion (that will have 2 solids, Carrier and API).
Thanks again for this clarification and the help from you and Dr. Waldman.
I will keep both of you posted.
Best Regards,
Sincerely,
Debashis
The geometry of the 2021 paper is easier to handle. I am a bit worried about the API 10 micron particles but they did it with MFiX so it must be doable. Good luck and keep us posted on your progress.
Dr. Waldman,
I was able to successfully install MFiX 25.3. I followed your suggestion and the reinstallation of CONDA and Python as well as the Windows environment and it worked. I will try to open the file aerolizer-fixed-cgw.zip that you have send and work on it. I will keep you posted. Thanks and Best Regards,
Sincerely,
Debashis
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I am trying to upload this Zipped file. The size is 105 MB which lower than 250 MB. Why am I getting the error message “Sorry, that file is too big (maximum size is 250 MB). Why not upload your large file to a cloud sharing service, then paste the link?”
Please let me know how I can upload this Zip file of 105 MB.
Thanks and Best Regards,
Debashis
Any suggestion how to share this Zipped file of approximately 105 MB size will be very helpful. I am confused why it is not allowing me to upload this even when it is much smaller than 250 MB.
Any alternative method will be very useful.
Look forward to hearing from you.
Thanks and Regards,
Debashis
Can you upload to Google Drive?
Dr. Waldman,
Here is the link for the google drive for the Zipped file.
Please let me know if you can access it. Or let me know if you need me to share it in a different way.
It is giving some error on meshing. Also we need to specify the Capsule area as particles. Somehow I cannot access the capsule area.
I look forward to hearing from you.
Thanks and Regards
Debashis
Please give access to “Anyone with link”. Otherwise you can reset the simulation before creating the bug report, this should bring the size down. I don’t know why you cannot attach the 105MB file, the limit is set to 250 MB.
What do you mean by “we need to specify the Capsule area as particles”?
Dr. Dietikar, I have now given access to anyone with link
Francesca-et-al-2022-DPI-rotation.pdf (4.8 MB)
I have simulate this particular case (attached paper). The particles are within the capsule.
Now you should be able to access the zip file. I am also confused why it did not allow me to attach is 105 MB file. But sharing by google drive is also fine. Please let me know if you access it. Once the model starts running with 1 solid (Carrier particle), I will introduce the 2nd solid (API) and finally rotation.
Thanks and Best Regards,
Sincerely,
Debashis
The link for the zip file and the script as well as the error message is MFiX - Google Drive
Thanks and Regards
Debashis
I have access, thanks. There are several issues:
- You need to flip the stl normals so they point towards the fluid region.
- Your mesh is too coarse to resolve the kind of sieve (highlighted in blue).
- The capsule is incomplete (highlighted in red).
- The outlet doesn’t reach ymax. Reduce ymax a bit so it is below the stl extend.
There may be more than that, but you need to fix these first before continuing. As I said earlier, you may not be able to run this with a rotating capsule and resolve the fluid flow inside and outside of it.
Aerolizer_1mm_share3_capsule_only.stl (414.1 KB)
Aerolizer_1mm_share3_device_only.stl (190.9 KB)
Dr. Dietikar,
Thank you. I will try to implement your suggestions. I will keep you posted.
I also have these separate CAD files for the device and the capsule. I may build a similar model but with these two separate CAD files. I will keep you posted.
Thanks and Regards,
Debashis