LAMMPS (28 Mar 2023 - Development) dimension 2 units micro atom_style sph variable R equal 0.5 # radius of sphere micrometers variable a equal $R/5 # lattice spacing micrometers variable a equal 0.5/5 variable L equal $R*3 variable L equal 0.5*3 variable T equal 300. variable rho_0 equal 1. # density picograms/micrometer^3 variable c_0 equal 100. # speed of sound micrometers/microsecond variable mu equal 1. # dynamic viscosity picogram/(micrometer-microsecond) variable h equal $a*4.5 # kernel function cutoff micrometers variable h equal 0.1*4.5 variable mass equal $a*$a*$a*${rho_0} variable mass equal 0.1*$a*$a*${rho_0} variable mass equal 0.1*0.1*$a*${rho_0} variable mass equal 0.1*0.1*0.1*${rho_0} variable mass equal 0.1*0.1*0.1*1 variable dt equal 1e-3 # timestep microseconds variable skin equal 0.2*$h variable skin equal 0.2*0.45 region box block -$L $L -$L $L 0 $a units box region box block -1.5 $L -$L $L 0 $a units box region box block -1.5 1.5 -$L $L 0 $a units box region box block -1.5 1.5 -1.5 $L 0 $a units box region box block -1.5 1.5 -1.5 1.5 0 $a units box region box block -1.5 1.5 -1.5 1.5 0 0.1 units box create_box 2 box Created orthogonal box = (-1.5 -1.5 0) to (1.5 1.5 0.1) 2 by 2 by 1 MPI processor grid lattice sq $a lattice sq 0.1 Lattice spacing in x,y,z = 0.1 0.1 0.1 create_atoms 1 box Created 900 atoms using lattice units in orthogonal box = (-1.5 -1.5 0) to (1.5 1.5 0.1) create_atoms CPU = 0.001 seconds region sphere sphere 0 0 0 $R units box region sphere sphere 0 0 0 0.5 units box set region sphere type 2 Setting atom values ... 81 settings made for type group fluid type 1 819 atoms in group fluid group sphere type 2 81 atoms in group sphere mass * ${mass} mass * 0.001 set group all sph/rho ${rho_0} set group all sph/rho 1 Setting atom values ... 900 settings made for sph/rho pair_style sdpd/taitwater/isothermal $T ${mu} 76787 # temperature viscosity random_seed pair_style sdpd/taitwater/isothermal 300 ${mu} 76787 pair_style sdpd/taitwater/isothermal 300 1 76787 pair_coeff * * ${rho_0} ${c_0} ${h} pair_coeff * * 1 ${c_0} ${h} pair_coeff * * 1 100 ${h} pair_coeff * * 1 100 0.45 fix 1 fluid sph fix 2 sphere rigid/meso single 1 rigid bodies with 81 atoms fix 2d all enforce2d neighbor ${skin} bin neighbor 0.09 bin neigh_modify delay 0 every 1 check yes timestep ${dt} timestep 0.001 dump dump_id all atom 100 dump.lammpstrj thermo 100 thermo_style custom step time nbuild ndanger run 10000 Generated 0 of 1 mixed pair_coeff terms from geometric mixing rule Neighbor list info ... update: every = 1 steps, delay = 0 steps, check = yes max neighbors/atom: 2000, page size: 100000 master list distance cutoff = 0.54 ghost atom cutoff = 0.54 binsize = 0.27, bins = 12 12 1 1 neighbor lists, perpetual/occasional/extra = 1 0 0 (1) pair sdpd/taitwater/isothermal, perpetual attributes: half, newton on pair build: half/bin/atomonly/newton stencil: half/bin/2d bin: standard Per MPI rank memory allocation (min/avg/max) = 6.463 | 6.463 | 6.463 Mbytes Step Time Nbuild Ndanger 0 0 0 0 100 0.1 0 0 200 0.2 0 0 300 0.3 0 0 400 0.4 1 0 500 0.5 1 0 600 0.6 1 0 700 0.7 2 0 800 0.8 2 0 900 0.9 2 0 1000 1 3 0 1100 1.1 3 0 1200 1.2 3 0 1300 1.3 4 0 1400 1.4 4 0 1500 1.5 4 0 1600 1.6 5 0 1700 1.7 5 0 1800 1.8 5 0 1900 1.9 6 0 2000 2 6 0 2100 2.1 6 0 2200 2.2 7 0 2300 2.3 7 0 2400 2.4 7 0 2500 2.5 8 0 2600 2.6 8 0 2700 2.7 8 0 2800 2.8 9 0 2900 2.9 9 0 3000 3 9 0 3100 3.1 10 0 3200 3.2 10 0 3300 3.3 11 0 3400 3.4 11 0 3500 3.5 11 0 3600 3.6 12 0 3700 3.7 12 0 3800 3.8 12 0 3900 3.9 12 0 4000 4 13 0 4100 4.1 13 0 4200 4.2 14 0 4300 4.3 14 0 4400 4.4 14 0 4500 4.5 15 0 4600 4.6 15 0 4700 4.7 15 0 4800 4.8 16 0 4900 4.9 16 0 5000 5 16 0 5100 5.1 17 0 5200 5.2 17 0 5300 5.3 17 0 5400 5.4 17 0 5500 5.5 18 0 5600 5.6 18 0 5700 5.7 18 0 5800 5.8 19 0 5900 5.9 19 0 6000 6 19 0 6100 6.1 20 0 6200 6.2 20 0 6300 6.3 20 0 6400 6.4 21 0 6500 6.5 21 0 6600 6.6 21 0 6700 6.7 22 0 6800 6.8 22 0 6900 6.9 22 0 7000 7 23 0 7100 7.1 23 0 7200 7.2 23 0 7300 7.3 24 0 7400 7.4 24 0 7500 7.5 24 0 7600 7.6 25 0 7700 7.7 25 0 7800 7.8 26 0 7900 7.9 26 0 8000 8 26 0 8100 8.1 26 0 8200 8.2 27 0 8300 8.3 27 0 8400 8.4 28 0 8500 8.5 28 0 8600 8.6 28 0 8700 8.7 29 0 8800 8.8 29 0 8900 8.9 29 0 9000 9 30 0 9100 9.1 30 0 9200 9.2 30 0 9300 9.3 30 0 9400 9.4 31 0 9500 9.5 31 0 9600 9.6 31 0 9700 9.7 32 0 9800 9.8 32 0 9900 9.9 32 0 10000 10 33 0 Loop time of 13.5306 on 4 procs for 10000 steps with 900 atoms Performance: 63855371.888 ns/day, 0.000 hours/ns, 739.067 timesteps/s, 665.160 katom-step/s 98.8% CPU use with 4 MPI tasks x no OpenMP threads MPI task timing breakdown: Section | min time | avg time | max time |%varavg| %total --------------------------------------------------------------- Pair | 12.327 | 12.56 | 12.738 | 4.3 | 92.83 Neigh | 0.0043391 | 0.0044297 | 0.0045381 | 0.1 | 0.03 Comm | 0.53746 | 0.71463 | 0.94685 | 18.1 | 5.28 Output | 0.021884 | 0.02228 | 0.023428 | 0.4 | 0.16 Modify | 0.14457 | 0.14548 | 0.14643 | 0.2 | 1.08 Other | | 0.08351 | | | 0.62 Nlocal: 225 ave 228 max 222 min Histogram: 1 0 0 1 0 0 1 0 0 1 Nghost: 438.25 ave 442 max 434 min Histogram: 1 0 0 0 0 1 1 0 0 1 Neighs: 10152.2 ave 10328 max 9853 min Histogram: 1 0 0 0 0 0 0 1 1 1 Total # of neighbors = 40609 Ave neighs/atom = 45.121111 Neighbor list builds = 33 Dangerous builds = 0 Total wall time: 0:00:13