How to input a PSD file in MP-PIC mfix on HPC?

MFiX How to
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#1

I have a PSD file (Attached) that I want the MP-PIC to take the size distribution from.

In the GUI on my laptop - I can go to solids then PIC then insert a PSD and enter this custom file (CDF attached)
CDF_riser_particle.txt (3.1 KB)

Distribution_glass_beads_CDF

  1. Do I still need to define the partilce diameter?
  2. How do I know MFIX is taking this user defined distribution in the simulation?
  3. If I want to run this on the HPC from commandline - do I just include the PSD.txt file in the same directory or do Ineed to remake the solver?
#2

I am not seeing the actual text file attached, but based on the plot, it looks like the mean is computed with an error (nan), and the unit may be wrong (size goes up to 120 meters!), so there could be something wrong with the file.

  1. You need to define a particle diameter. This will be used only in ICs or BCs where you do not want to use the PSD.
  2. For each IC or BC region that have solids, you can use a uniform size (form size defined in 1.) or use one of the PSDs defined in the Solids>PIC particle size distribution table.
  3. It is recommended to setup the simulation with the GUI. The GUI will rename PSD.txt into the appropriate file for each ICs and/or BCs defined in 2. For example, If you use a PSD.txt for IC#2, phase#1, it will be copied and renamed IC_PSD_0002_0001.txt. Once you have set the simulation with the GUI, you can run it through command line and the file will already be in the project file. If you want to set the simulation by manually editing the .mfx file, you will have to manually copy and correctly rename the file.

Please review the pic mixer or hopper_custom_psd setups for some examples of a custom PSD with DEM and PIC.

image
image1571×1069 132 KB

#3

Thanks for the detailed response.
Yes there was an error in the PSD.text file. The new PSD looks correct:

Distribution_glass_beads_CDF

I will try out the rest of the steps and let you know - thanks!

#4

Dear Jeff,

I tried to select the PSD in the IC and the BC in the GUI on my local machine -

However, I get this error and mfix just stops and does not proceeed further

Saving Mesh connectivity and flags…
Setting master from flags…
Gather and Write MasterList…
Saving Mesh info for Scalar cells…
Saving Mesh info for U-MOMENTUM cells…
Reading mesh stats: C:\Users\UB07846\final_solid_case_orig_dimension\MESH_STATS.LOG
Saving Mesh info for V-MOMENTUM cells…
Saving Mesh info for W-MOMENTUM cells…
At line 254 of file C:\Users\UB07846\Anaconda3\envs\mfix-22.1.1\share\mfix\src\model\des\des_psd_mod.f
Fortran runtime error: Bad integer for item 1 in list input

WROTE BOUNDARY IN VTK FILE : OWN_STL_FILE_boundary.vtk
PRE_PROCESSING COMPLETE.

#5

Can you please attach the PSD file? The code has an issue reading the first line.

#6

Sure. Here it is
CDF_riser_particle.txt (6.3 KB)

#7

I think I got the issue:
The first line of the file needs to be a proper integer.

I fixed it and now its running:
will look out for other errors!

#8

Dear Dr. Dietiker,

As you predicted, it generated two files

BC_PSD_0003_0001.txt and
IC_SD_0.001_0001.txt

So now if I have to put this simulation on the HPC. I will have to manually copy these files in the directory and then use the command line to queue the job, right?

#9

Yes, now you can copy these files along the other ones (.mfx, geometry_*.stl) to your HPC.

Please make sure you add the parcel diameter in the vtk files so you can visualize the parcels properly (since they don’t have a uniform size). You will use the diameter to scale the parcels in Paraview.

#10

Got it thanks Dr. Dietiker!