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lammps/examples/granregion/in.granregion.funnel
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in.granregion.funnel
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# pour particles into cone-shaped funnel, settle them, let them run out bottom
variable name string funnel_pour
thermo_modify flush yes
units si
variable PI equal 3.141592653589
variable seed equal 14314
###############################################
# Geometry-related parameters
###############################################
variable xlo equal 10
variable xhi equal 40
variable ylo equal 10
variable yhi equal 40
variable zlo equal -20
variable zhi equal 50
variable xc equal 25
variable yc equal 25
variable zconehi equal 50
variable zconelo equal 10
variable zcyllo equal 0
variable radconelo equal 2
variable radconehi equal 20
################################################
# Particle sizes
################################################
variable rlo equal 0.25
variable rhi equal 0.5
variable dlo equal 2.0*${rlo}
variable dhi equal 2.0*${rhi}
variable skin equal ${rhi}
###############################################
# Granular contact parameters
###############################################
variable coeffRes equal 0.1
variable coeffFric equal 0.5
variable density equal 1.0
variable EYoung equal 10^5
variable Poisson equal 2.0/7.0
variable GShear equal ${EYoung}/(2*(1+${Poisson}))
variable gravity equal 1.0
variable reff equal 0.5*(${rhi}+${rlo})
variable meff equal ${density}*4.0/3.0*${PI}*${reff}^3
variable min_mass equal ${density}*4.0/3.0*${PI}*${rlo}*${rlo}*${rlo}
variable max_mass equal ${density}*4.0/3.0*${PI}*${rhi}*${rhi}*${rhi}
## Typical way to set kn, kt, etc.:
variable kn equal 4.0*${GShear}/(3*(1-${Poisson}))
variable kt equal 4.0*${GShear}/(2-${Poisson})
variable a equal (-2.0*log(${coeffRes})/${PI})^2
variable gamma_n equal sqrt($a*2*${kn}/${min_mass}/(1+0.25*$a))
variable gamma_t equal ${gamma_n}*0.5
variable tcol equal ${PI}/sqrt(2*${kn}/${min_mass}-${gamma_n}/4.0)
variable dt equal ${tcol}*0.05
timestep ${dt}
###############################################
variable dumpfreq equal 1000
variable logfreq equal 1000
newton off
atom_style sphere
boundary p p f
region boxreg block ${xlo} ${xhi} ${ylo} ${yhi} ${zlo} ${zhi}
create_box 1 boxreg
pair_style gran/hertz/history &
${kn} ${kt} ${gamma_n} ${gamma_t} ${coeffFric} 1
pair_coeff * *
neighbor ${skin} bin
thermo ${logfreq}
comm_style brick
comm_modify mode multi group all vel yes
balance 1.1 shift xyz 20 1.1
fix bal all balance 10000 1.1 shift xyz 20 1.01
####################### Options specific to pouring #########################
# insertion region for fix/pour
region insreg cylinder z ${xc} ${yc} 10 30 50 side in units box
# define cone and cylinder regions - see lammps doc on region command
# note new open options
region cylreg cylinder z ${xc} ${yc} ${radconelo} &
${zcyllo} ${zconelo} side in units box &
open 2 #Top is open
region conereg cone z ${xc} ${yc} ${radconelo} ${radconehi} &
${zconelo} ${zconehi} side in units box &
open 1 open 2 #Bottom and top are open
region hopreg union 2 conereg cylreg
fix grav all gravity ${gravity} vector 0 0 -1
fix 1 all nve/sphere
fix hopper3 all wall/gran/region hertz/history &
${kn} ${kt} ${gamma_n} ${gamma_t} ${coeffFric} 1 region hopreg
fix ins all pour 2000 1 42424 region insreg &
diam range ${dlo} ${dhi} dens ${density} ${density}
#dump 1 all custom ${dumpfreq} ${name}.dump &
# id type mass diameter x y z
#dump 2 all image 4000 image.*.jpg type type &
# axes yes 0.8 0.02 view 60 -30 zoom 3.0 &
# box no 0.0 axes no 0.0 0.0
#dump_modify 2 pad 6
thermo_style custom step cpu atoms ke
thermo_modify flush yes lost warn
# Initial run to fill up the cone
run 20000
unfix ins
run 150000
# remove "plug" - need to redefine cylinder region & union
region cylreg delete
region hopreg delete
region cylreg cylinder z ${xc} ${yc} ${radconelo} &
${zcyllo} ${zconelo} side in units box &
open 1 open 2 #Bottom & top are open
region hopreg union 2 cylreg conereg
unfix hopper3
fix hopper3 all wall/gran/region hertz/history &
${kn} ${kt} ${gamma_n} ${gamma_t} ${coeffFric} 1 region hopreg
run 100000
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