hey! so I’m trying to design this rectangular receiver that has hexagonal obstructions in it.
I essentially want to see how the obstructions affect the flow of the solid particle through the receiver.
I created the STL file and uploaded onto the MFix platform. I was able to specify the regions and the boundary conditions, however when I run the software, i keep getting an error regarding the particles and I’m not sure how to go about it. do I need to specify the Van der Waal forces?
Please provide a description of the error you are getting.
I was able to figure out where my error was with the previous issue.
the problem is when I run it.
I essentially want to simulate how a particle would behave around a hexagonal obstruction.
I specified the regions for the wall and based on the facets, it ignored the hexagonal region.
but when i run the simulation, the particles are centered inside the obstruction.
what parameter do you i need to change for the particle to flow outside the obstruction.
You need to flip the normal vectors of your STL file: 12. Frequently Asked Questions — MFiX 22.3 documentation
When I changed the vectors, this is the message I get:
“Starting C:\Users\shwet\anaconda3\envs\mfix-22.2.2\Scripts\mfixsolver.exe -s -f C:\Users\shwet\OneDrive\Desktop\Thesis\modelling\3dhopper\hexrec\desktop\hexrec.mfx
MFiX running: elapsed time 0:00:00
Previous MFiX run is resumable. Reset job to edit model
MFiX process has stopped
Reading mesh stats: C:\Users\shwet\OneDrive\Desktop\Thesis\modelling\3dhopper\hexrec\desktop\MESH_STATS.LOG”
there are no errors reported but the simulation wont run.
Please attach all input files, including the STL. You can select “Submit bug report” from the main menu to create a ZIP file containing all relevant inputs.
(Unfortunately the zip file feature does not work properly in MFIX 22.3 but I see that you are using 22.2.2 so it should be OK)
Program received signal SIGFPE: Floating-point exception - erroneous arithmetic operation.
Backtrace for this error:
#0 vtk_out_mod_MOD_print_histogram
at /usr/local/src/conda/mfix-solver-22.3/model/cartesian_grid/vtk_out.f:3459
#1 vtk_out_mod_MOD_save_mesh_statistics
at /usr/local/src/conda/mfix-solver-22.3/model/cartesian_grid/vtk_out.f:3245
#2 cut_cell_preproc_MOD_cut_cell_preprocessing
...
3456 DO H = HISTO_START,HISTO_DIVS
3457
3458 CELLS_IN_BIN = GLOBAL_HISTO_VALUE(H)
3459 GLOBAL_HISTO_VALUE(H)=GLOBAL_HISTO_VALUE(H)/GLOBAL_NUMBER_OF_CELLS_WITH_THIS_CRITERION
3460
The variable GLOBAL_NUMBER_OF_CELLS_WITH_THIS_CRITERION (in addition to having a very long name!) is 0, triggering a zero-division error. Will follow up with more when I have a solution/workaround.
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There is an issue with the mesh. I am not entirely sure why, but there is a conflict with your stl file (wall BC) and the inlet BC. I simplified the STL file to only keep the hexagons. Please try the attached. There are solid walls (default BCs) all around, except the top inlet. Not sure if you actually need an outlet at the bottom. You may need to increase the spring stiffness a bit more because there are a few particles going through the walls.
hexrec.mfx (11.4 KB)
reciever-Hex_only.stl (7.1 KB)
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Thanks a lot Jeff and Charles, the simulation works!
can you tell me how you simplified the geometry incase I face the same issue in the future.