Initialising User_defined_Var_1

I’m loving the new interface for moving STLs, so I don’t need to edit text files to change the rotation speed (and can have linear motions as well if I need it in the future!)

I have one question - in the old versions, usr0.f had a section where a user variable (DES_USR_VAR(1,:)) was set based on the initial location of the particles. In the new version, usr0.f is effectively empty and the initialisation has obviously moved elsewhere.

Please could you let me know where it has moved to? I sometimes need to modify the initialisation conditions based on my geometry.

Many thanks

We’re glad you like the new keyframe feature.

The only places I see des_usr_var being assigned to (other than initialized to zero) are in
des/generate_particles_mod.f
and
des/read_particle_input.f

I searched for assignments to this variable by doing

grep -ir 'des_usr_var.*='

at the top of the MFiX source directory
r is recursive
i is case-insensitive

and the search pattern looks for the term to the left of an equal sign (with any characters in between, . in a regular expression is “any character” and * is “zero or more”)

– Charles

Thanks Charles,

I think I’ve found where I need to modify in generate_particles_mod.f (line 440) , but I’ve not yet got my head round doing the allocation based on location (presumably defined in locspot).
I have a handy way round though - I just run for 0.001s and edit the particle output file with the user variable values I want.

Separately, the old version did have a handy feature which was to change the rotation speed during a simulation, I used this to allow the particles to settle before turning on the mixer. Is that still possible? I was wondering about using ‘2*(time>1.5)’ or similar in the moving surface section but can’t find a suitable keyword for the current simulated time.

You can change the rotation speed with a keyframe file.