We have modified MFiX to take particle input from a CSV file rather than the particle_input.dat file with its fixed format and header. The old format is still supported but we strongly suggest using the CSV format. We have several tutorials which use particle_input.csv: fb_sqp_particle_input (SQP), fb_gsp_particle_input (GSP), fluid_bed_2d (DEM), mixer_3d (DEM), screwfeeder_3d (DEM), and hopper_3d (DEM) all use the CSV particle input format.
For CGP, each row in the CSV file represents one parcel, not an individual particle. You will have to specify statistical weight or real particle size. If your script can write this CSV, it can be loaded into MFiX as the initial particle configuration. Let us know if you need help with this.
You may also find this thread helpful MFIX-24.3.1 bimodal grain size from cumulative size distribution
This shows a different approach to seeding, where a mass inlet is created at the top of the domain, and particles are allowed to fall and settle. You can select “Save particle positions at end of run” and run with the mass inlet for a fixed period of time, then remove the mass inlet and use that settled particle bed as your initial configuration (renaming particle_output.csv to particle_input.csv)
– Charles