# SPH example
# Andreas Aigner (CD Lab Particulate FLow Modelling, JKU)
# andreas.aigner@jku.at

#variables
variable      mass universe 0.086 #0.001
variable      h universe 0.012 #0.0012

variable      lat equal $h/1.2 # = 0.01
variable      lathalf equal ${lat}*0.5
variable      wallpos equal 0.1+${lathalf}
variable      skin equal $h*0.25
variable      eta equal 0.01*$h*$h

variable      ins01 equal 0.1-${lat}
variable      ins05 equal 0.5-${lat}


atom_style    sph 
atom_modify   map array sort 0 0
communicate   single vel yes

boundary      f f p   #periodic in z; fixed in y-direction
newton        off

dimension	    2

units         si
lattice       sq ${lat}

region        reg block -0.021 0.521     -0.021 0.5    -0.001 0.001  units box
create_box    2 reg

region        regWallOut block 0.01 0.49   0.01 0.5   -0.001 0.001 side out units box
region        regWall intersect 2 reg regWallOut
region        insreg block ${lat} 0.1  ${lat} 0.1  -0.001 0.001 units box
region        insreg2 block 0.10001 ${ins05}  ${lat} 0.05  -0.001 0.001 units box
create_atoms  1 region insreg
create_atoms  1 region insreg2
create_atoms  2 region regWall
mass          * ${mass}

group         fluid type 1
group         wall  type 2

neighbor      ${skin} bin

fix           m1 all property/global speedOfSound peratomtype 20. 20.
fix           m2 all property/global sl peratomtype $h $h
fix           m3 all property/global artViscAlpha peratomtype 4.1666e-3 4.1666e-3
fix           m4 all property/global artViscBeta peratomtype 0. 0.
fix           m5 all property/global artViscEta  scalar ${eta}
fix           m6 all property/global tensCorrEpsilon scalar 0.2
fix           m7 all property/global tensCorrDeltaP peratomtype ${lat} ${lat}

#sph pair style
# mhu = 1e-3 (water) ~ alpha * cAB * h
# for c=20 (10*vMax) and h=0.012 --> alpha=0.004166667
# pair_style    sph kernel_style h [artVisc alpha beta cAB eta] [tensCorr epsilon]
# artifical viscosity [Monaghan and Gingold (1983)] and tensile correction [Monaghan (2000)]

pair_style 	  sph/artVisc/tensCorr cubicspline2d $h artVisc tensCorr
#pair_coeff	  1 1 sph/artVisc/tensCorr
#pair_coeff    1 2 sph/artVisc/tensCorr
#pair_coeff    2 2 none
pair_coeff    * *

#sph fixes
# density
fix           density all sph/density/continuity
fix           corr all sph/density/corr shepard every 30
set           group all meso_rho 1000

# pressure
# fix         id group style type [if Tait: B rho0 gamma] (according to Monaghan 1994)
# B = c^2*rho0/gamma
# for c=20 --> B~60000
fix		        pressure all sph/pressure Tait 60000. 1000. 7.

#wall
#region        boxw block 0. 0.5  0. 0.1  0. 0.5 units box
# fix         id group wall/region/sph region_id r0 D (repulsive force similar to Lennard-Jones potential p1=4, p2=2)
#fix           boxwall_reg all wall/region/sph boxw ${lat} 5.0
#fix         id group wall/sph args (e.g: xplane lo hi) r0 D
fix           wall all wall/sph xplane  ${wallpos} NULL ${lathalf} 1.0

# time integration
# for c=20 --> dt~1e-5
timestep      1e-5
fix           integr fluid nve/sph
fix           integrWall wall nve/sph/stationary

#gravity
fix           gravi all gravity 9.81 vector 0.0 -1.0 0.0

#2d simulation
fix           only2d all enforce2d

# set sph kernels for all fix after all fixes are defined
set        group all sphkernel cubicspline2d

#output settings, include total thermal energy
thermo_style	custom step atoms ke vol cpu
thermo          1000
thermo_modify	lost ignore norm no

run           1
dump	      dmp all custom/vtk 1000 post/sph_*.vtk id type type x y z ix iy iz vx vy vz fx fy fz vx vy vz p p rho
run           5000

unfix         wall

run           200000

