Different initial condition for particle set

Submitted by mofazli on Fri, 12/11/2020 - 00:08

Hi,
I am working with liggghts to simulate the motion of a number of particles in a defined block. I have obtained some results for that, but I wanna see the initial condition effect on my result. To this end, I have changed the seed number in my insertion command

fix ins all insert/pack seed 32452843 distributiontemplate pdd1 vel constant 0. 0. 0. insert_every once overlapcheck yes all_in yes particles_in_region 417 region reg

which creates a set of particles with a different configuration. BTW, do you know any other parameter in liggghts which can make a difference in my initial condition? You can find the script file in my simulation here:

echo both
log ../DEM/log.liggghts
thermo_log ../DEM/post/thermo.txt

atom_style granular
atom_modify map array
communicate single vel yes

#boundary f f p
boundary p p p
newton off

units si

region reg block 0. 0.13 0. 0.13 0. 0.13 units box
create_box 1 reg

neighbor 0.018975 bin
neigh_modify delay 0

# Material properties required for new pair styles

fix m1 all property/global youngsModulus peratomtype 5.e7
fix m2 all property/global poissonsRatio peratomtype 0.45
fix m3 all property/global coefficientRestitution peratomtypepair 1 0.9
fix m4 all property/global coefficientFriction peratomtypepair 1 0.5

# pair style
pair_style gran model hertz tangential history #Hertzian without cohesion
pair_coeff * *

# timestep, gravity
timestep 0.000001
#fix gravi all gravity 9.81 vector 0.0 0.0 -1.0

# walls
#fix xwalls1 all wall/gran model hertz tangential history primitive type 1 xplane 0.
#fix xwalls2 all wall/gran model hertz tangential history primitive type 1 xplane 0.13
#fix ywalls1 all wall/gran model hertz tangential history primitive type 1 yplane 0.
#fix ywalls2 all wall/gran model hertz tangential history primitive type 1 yplane 0.13
#fix zwalls1 all wall/gran model hertz tangential history primitive type 1 zplane 0.
#fix zwalls2 all wall/gran model hertz tangential history primitive type 1 zplane 0.16

# particle distributions and insertion
fix pts1 all particletemplate/sphere 15485863 atom_type 1 density constant 1120 radius constant 0.006325
fix pdd1 all particledistribution/discrete 15485867 1 pts1 1.0

#region and insertion
#region bc cylinder z 0.0 0.0 0.05 0.0 1.26 units box

#particle insertion
#fix ins all insert/pack seed 32452843 distributiontemplate pdd1 vel constant 0. 0. 1. insert_every once overlapcheck yes all_in yes particles_in_region 1000 region reg
fix ins all insert/pack seed 32452843 distributiontemplate pdd1 vel constant 0. 0. 0. insert_every once overlapcheck yes all_in yes particles_in_region 417 region reg

# apply nve integration to all particles that are inserted as single particles
fix integr all nve/sphere #wenn das ausgeblendet, dann kein vel update

# screen output
compute rke all erotate/sphere
thermo_style custom step atoms ke c_rke vol
thermo 1000
thermo_modify lost ignore norm no
compute_modify thermo_temp dynamic yes

# insert the first particles so that dump is not empty
run 1
dump dmp all custom 5000 post/dump.liggghts_init id type type x y z ix iy iz vx vy vz fx fy fz omegax omegay omegaz radius

run 30000 upto
write_restart post/restart/liggghts.restart