# 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

AttachmentSize
8.09 KB

### Forums:

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

### Increasing mass rate

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,