Need help to insert bigger particles in my simulation

Submitted by gibel on Sat, 02/25/2023 - 11:39

Hello guys,
Recently I am having a problem in particle insertion in drum.

I don't have problem with small size of particles with small drum. However, I am trying to use a bigger drum with width 2m and diameter 6m (si unit).
For bigger geometry I am trying to insert two types of particles with 1 m and 0.8 m. Whenever I increased the particles size, it doesn't increase the required number of particles in insertion. Instead it just insert 10, or 12 particles. I gues it is trying to control some of the calculation like fill mass rate or insertion.

I am using folowing commands to control the insertion:

variable filltime equal 50 #seconds #filltime to generate the particles

variable fillmass equal 1000 #kg #total mass of bulk material

variable fillmassrate equal ${fillmass}/${filltime} #kg/s #mass rate for the particle generation

variable fillsteps equal ${filltime}/${dt} #Transform time to iteration steps dt = 0.00001

I am inserting particles with these comands:

fix pts1 all particletemplate/sphere 49979693 atom_type 1 density constant ${density} radius constant ${radius1}

fix pts2 all particletemplate/sphere 67867979 atom_type 1 density constant ${density} radius constant ${radius2}

fix pdd1 all particledistribution/discrete 86028121 ${nradii} pts1 ${frac1} pts2 ${frac2}

#fix pdd1 all particledistribution/discrete/numberbased 32452867 ${nradii} pts1 ${frac1} pts2 ${frac2}

fix ins_mesh all mesh/surface/planar file meshes/Insertionsface.stl type 1 scale 0.9

fix ins all insert/stream seed 86028157 distributiontemplate pdd1 &
mass ${fillmass} massrate ${fillmassrate} overlapcheck yes all_in yes vel constant 0 0 -0.75 &
insertion_face ins_mesh extrude_length 0.5


Even though I increased the mass it doesn't work.
How can I make it correct so that it insert enough particles size 1m and 0.8 m ?
I want particles to fill atleast half of drum.

I have attached my script file here.

Hoping for some help.

Thank you

Plain text icon light input file8.09 KB

jachueire | Mon, 03/13/2023 - 13:26

Hello, have you tried increasing (a lot) the values of "fillmass"? Like 50 times?
Using 1-meter diameter spherical particles with a density of 2500 kg/m3 (1 particle ~=1.3ton?) may be filling the mass values you chose too fast.

You can also try to change the insertion type to use the "number of particles" (nparticles) instead of "mass".

gibel | Sat, 03/18/2023 - 06:54

Hello Jachueire,
Thanks for your answer.

I wiill try running my simulation by increasing the values of fill mass. But my simulation need to insert particles volumewise. So Second option doesn't work for me in this case.
Thank you