Hello LIGGGHTS forum, I really appreciate your help.
I have been trying to do a simple simulation. Recently I noticed that more particles are created when iteration is increase. I actually need only one particle in my dump file. I have included my script and dump.data file here with few questions.
Could you kindly help me?
Scripts:
# Initialize
atom_style granular
atom_modify map array
###########################################################################################
#Describe boundary
boundary f f f
newton off
communicate single vel yes
units si
####################################################################################################################
#Declare domain number of materials as domain
region domain block -0.5 0.1 -0.2 0.2 -0.4 0.15 units box
create_box 1 domain
#####################################################################################################################
#Neighbor listing
neighbor 0.001 bin
neigh_modify delay 0
#####################################################################################################################
## Material and interaction properties
fix m1 all property/global youngsModulus peratomtype 5.e6
fix m2 all property/global poissonsRatio peratomtype 0.4
fix m3 all property/global coefficientRestitution peratomtypepair 1 0.2
fix m4 all property/global coefficientFriction peratomtypepair 1 0.4
fix m5 all property/global k_finnie peratomtypepair 1 1.0
fix m6 all property/global coefficientRollingFriction peratomtypepair 1 0.01
#######################################################################################################################
#New pair style, define physics
pair_style gran model hertz tangential history #Hertzian without cohesio
pair_coeff * *
#############################################################################################
#Time step
timestep 0.00001
##############################################################################################
# Integrator and gravity
fix integrate all nve/sphere
fix gravi all gravity 9.81 vector 0.0 0.0 -1.0
#############################################################################################
#Particle insertion
fix cad all mesh/surface/stress file meshes/simple_chute.stl type 1 wear finnie
fix inface all mesh/surface file meshes/insertion_face.stl type 1
fix granwalls all wall/gran model hertz tangential history mesh n_meshes 1 meshes cad
fix mass all massflow/mesh mesh inface count once point_at_outlet 0. 0. 0.
#######################################################################################################
# Particle properties
fix pts1 all particletemplate/sphere 15485863 atom_type 1 density constant 20 radius constant 0.0015
#Describe the composition of the particle distribution
fix pdd1 all particledistribution/discrete 32452843 1 pts1 1.0
##############################################################################################################
#Define insertion region, velocity for particle
group nve_group region domain
region bc cylinder z 0.0 0.0 0.015 0.05 0.12 units box
fix 1 all nve velocity all pts1 NULL 0.5 NULL units box
##############################################################################################################
#particle insertion
fix ins nve_group insert/pack seed 32452867 distributiontemplate pdd1 insert_every 1 overlapcheck yes all_in yes particles_in_region 1 region bc
################################################################################################################
compute 1 all erotate/sphere
thermo_style custom step atoms ke c_1 vol
thermo 1000
thermo_modify lost ignore norm no
compute_modify thermo_temp dynamic yes
##########################################################################################################################
run 100
#########################################################################################################################
dump dmp all custom/vtk 200 particleB/chute_*.vtk id type type x y z ix iy iz vx vy vz fx fy fz omegax omegay omegaz radius
dump dumpstress all mesh/gran/VTK 200 particleB/mesh_*.vtk stress wear cad
dump dmp0 all custom 10 particleB_dump/dump*.data id type type x y z vx vy vz fz fy fz
#################################################################################################
#unfix ins
run 1000000 upto
unfix ins
@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@
dump.data file:
==============
when it started - step 10:
ITEM: TIMESTEP
10
ITEM: NUMBER OF ATOMS
1
ITEM: BOX BOUNDS ff ff ff
-0.5 0.1
-0.2 0.2
-0.4 0.15
ITEM: ATOMS id type type x y z vx vy vz fz fy fz
1 1 1 0.00162983 0.00252669 0.052531 0 0 -0.0018639 -2.77371e-06 0 -2.77371e-06
-------------------------------------------------------------------------------------------------------------------------------------------------------
later on - step 30000
ITEM: TIMESTEP
37970
ITEM: NUMBER OF ATOMS
10
ITEM: BOX BOUNDS ff ff ff
-0.5 0.1
-0.2 0.2
-0.4 0.15
ITEM: ATOMS id type type x y z vx vy vz fz fy fz
7 1 1 -0.076216 -0.00267228 0.134048 -0.393453 -0.0808271 0.476712 -2.77371e-06 0 -2.77371e-06
2 1 1 -0.456892 -0.00964288 -0.35402 -1.23492 -0.0131475 -1.5668 -2.77371e-06 0 -2.77371e-06
3 1 1 -0.378195 -0.00222328 -0.274897 -1.21475 0.0285308 -0.944636 -2.77371e-06 0 -2.77371e-06
5 1 1 -0.343139 0.0152948 -0.251435 -1.03138 -0.0476859 -0.636269 -2.77371e-06 0 -2.77371e-06
4 1 1 -0.17683 -0.00211806 -0.180424 -1.07222 -0.0348454 -0.428653 -2.77371e-06 0 -2.77371e-06
6 1 1 -0.143029 -0.00641894 -0.166236 -0.919677 -0.00845824 -0.381421 -2.37829e-07 6.4584e-08 -2.37829e-07
8 1 1 -0.0224919 -0.00848567 -0.115333 -0.595621 0.0874951 -0.245941 -2.23721e-07 7.00177e-09 -2.23721e-07
9 1 1 -0.0168881 0.00603514 -0.0223347 -0.422936 -0.0272437 1.79791 -2.77371e-06 0 -2.77371e-06
10 1 1 0.00935496 -0.00117298 -0.0777684 0 0 -1.73058 -2.77371e-06 0 -2.77371e-06
11 1 1 -0.0106077 0.00555359 0.0520806 0 0 -1.03191 -2.77371e-06 0 -2.77371e-06
@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@
My questions are:
1) Why number of atoms are increasing? I only need 1 atom in each dump.data. Is it possible to make onle 1 atom in each steps?
2) Is it possible to give time while inserting particles so that one leaves domain and another falls down?
Thank you so much in advanced.
mschramm | Fri, 01/29/2021 - 22:43
Once instead of 1
Change
Insert_every 1
To
Insert_every once
This will make it so the insertion is not called again.
laudari | Sun, 01/31/2021 - 17:05
But it creates only one flow,
Thank you for your reply. I have to create more than 50 flows one by one. Which means I have to drop particle one by one. When I changed to once it only drops 1 particle in entire simulation.
How do I fixed it ?
Thank you
mschramm | Sun, 01/31/2021 - 19:51
Confused
In your original post, you stated you only needed one particle.
You can always run your simulation to the point where you have all of your particles inserted.
Once they are inserted, use the unfix command to stop insertion.