Particle Orientation not changing in DEM-SQP simulation

MFiX How to
#1

Hello, I am working on case using DEM and SQP. However the particle orientation doesn’t changes as shows in this video below, looks as if particles are behaving just like spheres. I want to understand what am I doing wrong while defining the case. I want to study shear in non spherical particles.


I have also attached my case file.
smooth_sphero.zip (46.9 MB)
Any help would be appricieted

#2

You are using old modified versions of calc_collision_wall_mod.f and des_time_march.f that predate the SQP model. Please use the ones that come with the rotating drum dem tutorial instead.

#3

I replaced both of the files with those from rotating drum tutorial. However orientations are still not changing. How should I proceed

#4

Please upload all files (again) - thanks!

#5

Note, when I run this case - after updating calc_collision_wall_mod.f and des_time_march.f and rebuilding - I get a DT < DT_MIN. Recovery not possible! error at t=0.0489. I cannot reproduce your results.

#6

You also have 18 warnings about bad mesh quality and unsuccessful seeding.

#7

Please try the attached. I set NORM_G=0 to avoid the DT_MIN error.
calc_collision_wall_mod.f (53.8 KB)
data_kf_0004.txt (42 Bytes)
data_kf_0004.txt (42 Bytes)
des_time_march.f (11.1 KB)
particlebetweenplates.mfx (13.6 KB)
Plates (2).stl (684 Bytes)
usr0.f (2.9 KB)
usr1_des.f (2.8 KB)
usr_init_namelist.f (1.7 KB)
usr_mod.f (11.6 KB)

#8

Will these case files work with GSP as well?

#9

Have you tried it? Change the model type in the “Model setup” pane and then define the particle in the “Solids” pane. You should be able to generate a GSP based on the same superquadric shape parameters. Please let us know if this succeeds, or if you come across some problems.