# pour two types of particles (cohesive and non-cohesive) into cylinder
# 'turn' cylinder by changing direction of gravity, then rotate it.
# This simulates a rotating drum powder characterization experiment.

variable        name string rotating_drum_two_types

atom_style      sphere
units           lj

###############################################
# Geometry-related parameters
###############################################

variable        boxx equal 30
variable        boxy equal 30
variable        boxz equal 50

variable        drum_rad equal ${boxx}*0.5
variable        drum_height equal 20

variable        xc equal 0.5*${boxx}
variable        yc equal 0.5*${boxx}
variable        zc equal 0.5*${boxz}

###############################################
# Particle-related parameters
###############################################
variable        rlo equal 0.25
variable        rhi equal 0.5
variable        dlo equal 2.0*${rlo}
variable        dhi equal 2.0*${rhi}

variable        cyl_rad_inner equal ${drum_rad}-1.1*${rhi}

variable        dens equal 1.0

variable skin equal 0.4*${rhi}

#############
processors * * 1
region          boxreg block 0 ${boxx} 0 ${boxy} 0 ${boxz}
create_box      2 boxreg
change_box      all boundary p p f

pair_style      granular
pair_coeff      1 * hertz/material 1e5 0.2 0.3 tangential mindlin NULL 1.0 0.5 damping tsuji
pair_coeff      2 2 jkr 1e5 0.1 0.3 50 tangential mindlin NULL 1.0 0.5 rolling sds 1e3 1e3 0.1 twisting marshall 

variable        theta equal 0

region          curved_wall cylinder z ${xc} ${yc} ${drum_rad} 0 ${drum_height} side in rotate v_theta ${xc} ${yc} 0 0 0 1
region          bottom_wall plane ${xc} ${yc} 0 0 0 1 side in rotate v_theta ${xc} ${yc} 0 0 0 1

region          insreg cylinder z ${xc} ${yc} ${cyl_rad_inner} ${drum_height} ${boxz}

fix             0 all balance 100 1.0 shift xy 5 1.1
fix             1 all nve/sphere
fix             grav all gravity 10 vector 0 0 -1
fix             ins1 all pour 2000 1 1234 region insreg diam range ${dlo} ${dhi} dens ${dens} ${dens}
fix             ins2 all pour 2000 2 1234 region insreg diam range ${dlo} ${dhi} dens ${dens} ${dens}

comm_modify     vel yes

neighbor        ${skin} bin
neigh_modify    delay 0 every 1 check yes

fix             3 all wall/gran/region granular hertz/material 1e5 0.1 0.3 tangential mindlin NULL 1.0 0.5 damping tsuji region curved_wall
fix             4 all wall/gran/region granular hertz/material 1e5 0.1 0.3 tangential mindlin NULL 1.0 0.5 damping tsuji region bottom_wall

thermo_style    custom step atoms ke v_theta
thermo_modify   lost warn
thermo          100

timestep        0.001

#dump           1 all custom 100 ${name}.dump id type radius mass x y z

#For removal later
compute         1 all property/atom radius
variable        zmax atom z+c_1>0.5*${drum_height}
group           delgroup dynamic all var zmax every 10000

run             2000

#Remove any particles that are above z > 0.5*drum_height
delete_atoms    group delgroup

#Add top lid
region          top_wall plane ${xc} ${yc} ${drum_height} 0 0 -1 side in rotate v_theta ${xc} ${yc} 0 0 0 1
fix             5 all wall/gran/region granular hertz/material 1e5 0.1 0.3 tangential mindlin NULL 1.0 0.5 damping tsuji region top_wall

# 'Turn' drum by switching the direction of gravity
unfix           grav
unfix           ins1
unfix           ins2
fix             grav all gravity 10 vector 0 -1 0

variable        theta equal 2*PI*elapsed/20000.0
run             3000