Solver crashing and issue with Mesh

[basud0817]

Please include project files - Main menu/Submit bug report - attach zip file here.
Aerolizer_1mm_share3.stl (1.4 MB)
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)

dpih_cfddem_2025-10-12T164643.606480.zip (12.0 MB)

Hello,
I am trying to run this case DPIH_CFDDEM_AEROLIZER_V1_1Solid_CarrierOnly_DEM.mfx developed based on the attached paper by Francesca et al. Somehow, when I am trying to run it is crashing with the attached error message. I am using MFiX-25.1.2. I am attaching the stl file and the zip file containing all the files in the folder. I have been trying to make it work for the last few weeks. Resolved all the syntax and other keyword errors and now having this issue. I need some help to resolve the issue here so that I can run the simulations. Kindly have a look at the file and let me know where I am getting it wrong. Once I get this one solid (Carrier particle) case running, I will work on the 2 solids (carrier particles and API) case.
Thanks and Best Regards,
Sincerely,
Debashis
DPIH_CFDDEM_AEROLIZER_V1_1Solid_CarrierOnly_DEM.mfx (9.0 KB)

[cgw]

@basud0817
I cannot get this case to run at all. The file geometry_0004.stl is missing, and if I copy Aerolizer_1mm_share3.stl to geometry_0004.stl, I get warnings about “No standard fluid cells in domain”.

I know there’s an issue with the bug report in some older MFiX versions. If “Submit bug report” does not work, can you just make sure to attach all STL files from the run dir?

Better yet, try this case with MFiX 25.3. I know you were having some problems installing that due to some unresolved DLL issue with VTK. Do you possibly have access to another machine that you can try this on?

– Charles

[basud0817]

Aerolizer_1mm_share3.stl (1.4 MB)
dpih_cfddem_2025-10-13T141554.867731.zip (12.0 MB)
CHEMLOOPTRY4_FACETS_IGNORED.stl (27 Bytes)
CHEMLOOPTRY4_FACETS_IGNORED.stl (27 Bytes)
Aerolizer_1mm_share3.stl (1.4 MB)

geometry.stl (9.0 MB)
Dr. Waldman,
I have attached the zip file obtained from submit bug report and the stl files. Please let me know if you need anything else.
Thanks and Best Regards,
Sincerely,
Debashis

[basud0817]

Aerolizer_1mm_share3_segmented.onesolid.stl (6.5 MB)
segmented.mfx (4.8 KB)
segmented_2025-10-13T183645.713535.zip (30.8 MB)
Dr. Waldman, I got another stl file for the same geometry and I tested it. Looks like there was no error message when meshing. Just wanted to share this information if this is of any help. Here all cells are fluid cells (51200).

Thanks and Best Regards,
Sincerely,
Debashis

[cgw]

I suspect there is some problem with the original stl file Aerolizer_1mm_share3.stl but I haven’t figured out quite what the problem is. Note that both DPIH_CFDDEM_FACETS_READ.stl and DPIH_CFDDEM_FACETS_IGNORED.stl contain no facets.

I’m referring to the first case you uploaded - I haven’t checked the new files yet.

The other thing that is strange is that the “Geometry parameters” section is empty:

and clicking on “-” to delete the geometry leads to an error popup.

so it seems that something has gone wrong when importing this STL file. I’ll let you know if I find out more. I am glad you are having better results with a different STL file.

A few general suggestions:

1. Unless the aerolizer is 47 meters tall you probably want to set “STL file units” to mm.
2. Click “autosize” to set the domain extents to the size of the STL
3. In your “regions” setup, use “xmin/xmax/ymin/ymax/zmin/zmax” instead of numeric values.
   
   

[cgw]

Regarding my previous post, I see that “autoscale” does not seem to respect the “stl file units” setting. This is an MFiX bug which we will fix in the next release.

In the meanwhile, you can either enter the domain extents manually,

OR, possibly better, externally scale the STL file to the correct size:

C:>  conda activate mfix-25.3 # or 25.1.2
(mfix-25.3) C:> python
>>> import trimesh
>>> mesh = trimesh.load("input.stl")
>>> mesh.apply_scale(0.001)
>>> mesh.export("output.stl")

[jeff.dietiker]

I am looking at these files:

@basud0817

Aerolizer_1mm_share3_segmented.onesolid.stl (6.5 MB)
segmented.mfx (4.8 KB)
segmented_2025-10-13T183645.713535.zip (30.8 MB)

You did not set up any Boundary Condition region that would use the stl file as an input for the wall geometry. You also need inlets/outlets.

There are too many versions of the setup you want to troubleshoot in this post. My suggestion if you want better support is:

1. upgrade to MFiX 25.3
2. Get familiar with basic meshing operation (import stl file, size the domain, check normal vectors, assign BCs)
3. Only upload one version of the files you want support on, preferably the zip file that the GUI generates.

[basud0817]

Aerolizer_1mm_share3_segmented.onesolid.stl (6.5 MB)
segmented.mfx (9.4 KB)

Dr. Dietiker,
Here is the complete file and other error messages for this case. I think it will be better to focus on the other case involving Aerolizer_1mm_share3.stl and make it work.

segmented_2025-10-14T130218.747187.zip (15.5 MB)
Thanks and Regards,
Debashis

[basud0817]

Thank you. I will do as you suggest.
Debashis

[basud0817]

Thank you. I also faced the same problem. I will try this with 25.1.2 and subsequently with 25.3 when it works.
Thanks and Regards
Debashis

[jeff.dietiker]

I still don’t understand, you attached Aerolizer_1mm_share3_segmented.onesolid.stl but you are saying you want to focus on Aerolizer_1mm_share3.stl, and you also attached another zip. Please start another post with either:

1. One .mfx file and the corresponding .stl
2. One .zip file that contains all necessary files

Please do not attach both zip files and mfx and stl files. Before you send your setup, verify the dimensions of the stl file and adjust the MFiX domain extents. The snapshot you show suggests the scales are not right, which may explain why geometry_0004.stl is not written out.