variable nrun equal 1000
variable dump_count equal 10

variable nwall equal 4
variable w1 equal 67
variable w2 equal 71
variable w3 equal 75
variable w4 equal 79

variable x_cylinder equal 20
variable y_cylinder equal 17
variable r_cylinder equal 4

variable MASS  equal 1
variable TEMP  equal 0.4
variable VFLOW equal 0.5

units         lj
atom_style    atomic

lattice       fcc 0.3
region        sim_box block 0 84 0 34 0 10

boundary      p p p

create_box    2 sim_box
region        reg_cylinder cylinder z ${x_cylinder} ${y_cylinder} ${r_cylinder} EDGE EDGE

create_atoms  1 box

## setup obstacle ##
group  g_obst region reg_cylinder
group  g_flow subtract all g_obst
set    group g_obst type 2 

mass          1 ${MASS}
mass          2 ${MASS}

velocity  g_flow create ${TEMP} 4928459 rot yes dist gaussian
velocity  g_obst set    0.0 0.0 0.0

pair_style  lj/cut 1.122462
pair_coeff  1 1 1.0 1.0
pair_coeff  1 2 1.0 1.0
pair_coeff  2 2 1.0 1.0
pair_modify shift yes

neighbor      0.3 bin
neigh_modify  delay 0 every 20 check no

fix    1     g_flow nve
fix    2     g_flow wall/flow  x ${VFLOW} ${TEMP} 123 ${nwall} ${w1} ${w2} ${w3} ${w4}

variable dump_every equal ${nrun}/${dump_count}
variable thermo_every equal ${dump_every}
variable restart_every equal ${nrun}/10

##### uncomment for grid aggregation #####
#variable gr_Nx equal 42
#variable gr_Ny equal 17
#variable gr_Nz equal 1
#variable gr_Nevery equal ${dump_every}
#variable gr_Nrepeat equal 1
#variable gr_Nfreq equal ${dump_every}
#fix    3     g_flow ave/grid ${gr_Nevery} ${gr_Nrepeat} ${gr_Nfreq} ${gr_Nx} ${gr_Ny} ${gr_Nz} vx vy vz density/mass norm all ave one
#compute ct_gridId g_flow property/grid ${gr_Nx} ${gr_Ny} ${gr_Nz} id
#dump   dmp_grid  g_flow grid ${dump_every} grid.lammpstrj c_ct_gridId:grid:data f_3:grid:data[*]
##########################################

#dump   dmp_coord all atom ${dump_every} dump.lammpstrj

#compute ct_Temp   g_flow temp/com
#thermo_style custom step temp epair emol etotal press c_ct_Temp

#restart  ${restart_every} flow.restart

timestep 0.005
thermo   ${thermo_every}
run      ${nrun}