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# SRD viscosity demo - poydisperse spheres
units lj
atom_style sphere
atom_modify first big
dimension 2
# create big particles with 3 different types and diameters
lattice sq 0.3
region box block 0 10 0 10 -0.5 0.5
create_box 4 box
create_atoms 1 region box
group big type 1
set group big type/fraction 2 0.33 394895
set group big type/fraction 3 0.5 989894
group big type 2 3
set type 1*3 mass 1.0
velocity big create 1.44 87287 loop geom
# equilibrate big particles, repulsive only to prevent aggregation
pair_style lj/cut 1.12
pair_coeff 1 1 1.0 1.0 1.12
pair_coeff 2 2 1.0 2.0 2.24
pair_coeff 3 3 1.0 1.5 1.68
pair_coeff 4 4 0.0 1.0 0.0
neighbor 0.3 bin
neigh_modify delay 0 every 1 check yes
fix 1 big nve
fix 2 all enforce2d
#dump 1 all atom 10 dump.poly.equil
run 1000
#undump 1
unfix 1
unfix 2
# add small particles as hi density lattice
region plane block INF INF INF INF -0.001 0.001 units box
lattice sq 250.0
create_atoms 4 region plane
set type 4 mass 0.1
group small type 4
velocity small create 1.0 593849 loop geom
# delete overlaps
# must set *-4 cutoffs to non-zero values
pair_style lj/cut 2.5
pair_coeff 1 1 1.0 1.0
pair_coeff 2 2 1.0 2.0
pair_coeff 3 3 1.0 1.5
pair_coeff 1 4 0.0 1.0 0.5
pair_coeff 2 4 0.0 1.0 1.0
pair_coeff 3 4 0.0 1.0 0.75
pair_coeff 4 4 0.0 1.0 0.0
delete_atoms overlap 1.0 small big
# SRD run
reset_timestep 0
neighbor 0.3 multi
neigh_modify delay 0 every 1 check yes
comm_modify mode multi group big vel yes
neigh_modify include big
# no pairwise interactions with small particles
pair_style lj/cut 1.12
pair_coeff 1 1 1.0 1.0 1.12
pair_coeff 2 2 1.0 2.0 2.24
pair_coeff 3 3 1.0 1.5 1.68
pair_coeff 4 4 0.0 1.0 0.0
# use fix SRD to push small particles out from inside big ones
# if comment out, big particles won't see SRD particles
timestep 0.001
fix 1 big nve
fix 2 small srd 20 big 1.0 0.25 49894 shift yes 54979 &
search 0.2 inside ignore
fix 3 small viscosity 10 x y 50
fix 4 all enforce2d
# diagnostics
compute tbig big temp/sphere
variable pebig equal pe*atoms/count(big)
variable ebig equal etotal*atoms/count(big)
thermo_style custom step temp f_2[8] etotal v_pebig v_ebig press &
f_2[1] f_2[2] f_2[3] f_2[4] f_2[5] &
f_2[6] f_2[7] f_2[8] f_2[9] f_2[10] f_2[11]
thermo_modify temp tbig
thermo 1000
#dump 1 all atom 500 dump.poly.mp
#dump 1 all image 500 image.*.jpg type type zoom 1.6
#dump_modify 1 pad 6 adiam 1 1 adiam 2 2.0 adiam 3 1.5 adiam 4 0.1
run 50000
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