LAMMPS (7 Jul 2009) # 2d LJ obstacle flow dimension 2 boundary p s p atom_style atomic neighbor 0.3 bin neigh_modify delay 5 # create geometry lattice hex 0.7 Lattice spacing in x,y,z = 1.28436 2.22457 1.28436 region box block 0 40 0 10 -0.25 0.25 create_box 3 box Created orthogonal box = (0 0 -0.321089) to (51.3743 22.2457 0.321089) 4 by 1 by 1 processor grid create_atoms 1 box Created 840 atoms mass 1 1.0 mass 2 1.0 mass 3 1.0 # LJ potentials pair_style lj/cut 1.12246 pair_coeff * * 1.0 1.0 1.12246 # define groups region 1 block INF INF INF 1.25 INF INF group lower region 1 120 atoms in group lower region 2 block INF INF 8.75 INF INF INF group upper region 2 120 atoms in group upper group boundary union lower upper 240 atoms in group boundary group flow subtract all boundary 600 atoms in group flow set group lower type 2 120 settings made for type set group upper type 3 120 settings made for type # initial velocities compute mobile flow temp velocity flow create 1.0 482748 temp mobile fix 1 all nve fix 2 flow temp/rescale 200 1.0 1.0 0.02 1.0 fix_modify 2 temp mobile # Poiselle flow velocity boundary set 0.0 0.0 0.0 fix 3 lower setforce 0.0 0.0 0.0 fix 4 upper setforce 0.0 NULL 0.0 fix 5 upper aveforce 0.0 -0.5 0.0 fix 6 flow addforce 1.0 0.0 0.0 # 2 obstacles region void1 sphere 10 4 0 3 delete_atoms region void1 Deleted 36 atoms, new total = 804 region void2 sphere 20 7 0 3 delete_atoms region void2 Deleted 35 atoms, new total = 769 fix 7 flow indent 100 sphere 10 4 0 4 fix 8 flow indent 100 sphere 20 7 0 4 fix 9 all enforce2d # Run timestep 0.003 thermo 1000 thermo_modify temp mobile dump 1 all atom 100 dump.obstacle #dump 1 all custom 100 dump.custom id type x y z vx vy run 25000 Memory usage per processor = 1.6747 Mbytes Step Temp E_pair E_mol TotEng Press Volume 0 1.0004177 0 0 0.68689281 0.46218884 1142.8674 1000 1 -0.31542378 0 0.3711822 1.175277 1269.5736 2000 1 -0.41219854 0 0.27440745 1.1491113 1299.751 3000 1 -0.47091634 0 0.21568964 1.5138975 1319.4646 4000 1 -0.53218028 0 0.1544257 1.4947487 1368.5894 5000 1 -0.46667863 0 0.21992736 1.2479263 1416.3743 6000 1 -0.48435058 0 0.20225541 1.1547645 1435.6664 7000 1 -0.45166298 0 0.23494301 1.2360154 1436.1059 8000 1 -0.42767328 0 0.2589327 1.0669461 1445.2577 9000 1 -0.3731244 0 0.31348158 1.0759192 1437.8863 10000 1 -0.38390694 0 0.30269904 1.0086513 1433.1836 11000 1 -0.38602215 0 0.30058383 0.97948448 1433.262 12000 1 -0.39324632 0 0.29335966 1.0627957 1439.8189 13000 1 -0.38406328 0 0.3025427 1.0506023 1450.2548 14000 1 -0.39923996 0 0.28736602 1.0593743 1453.5768 15000 1 -0.39243934 0 0.29416664 1.0295791 1451.2386 16000 1 -0.39115558 0 0.2954504 0.99442342 1452.2425 17000 1 -0.37672706 0 0.30987892 1.1334027 1446.7615 18000 1 -0.39587578 0 0.2907302 1.0416836 1451.6676 19000 1 -0.37159192 0 0.31501406 0.97004312 1453.7464 20000 1 -0.37573625 0 0.31086973 1.0174394 1456.2812 21000 1 -0.37788053 0 0.30872545 0.93039844 1468.4444 22000 1 -0.38096917 0 0.30563681 1.0034608 1464.2511 23000 1 -0.37098283 0 0.31562315 0.98141206 1460.3666 24000 1 -0.37160721 0 0.31499877 0.98831948 1462.133 25000 1 -0.39191532 0 0.29469067 1.0326092 1457.8187 Loop time of 8.08862 on 4 procs for 25000 steps with 769 atoms Pair time (%) = 0.273889 (3.3861) Neigh time (%) = 0.0620313 (0.766896) Comm time (%) = 3.63789 (44.9754) Outpt time (%) = 0.321601 (3.97597) Other time (%) = 3.79321 (46.8957) Nlocal: 192.25 ave 235 max 157 min Histogram: 1 1 0 0 0 0 1 0 0 1 Nghost: 42.25 ave 46 max 38 min Histogram: 1 0 0 0 0 1 1 0 0 1 Neighs: 401.25 ave 540 max 283 min Histogram: 2 0 0 0 0 0 0 1 0 1 Total # of neighbors = 1605 Ave neighs/atom = 2.08713 Neighbor list builds = 1636 Dangerous builds = 0