LAMMPS (5 Oct 2007) # 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 tag type x y z vx vy run 25000 Memory usage per processor = 1.33138 Mbytes Step Temp E_pair E_mol TotEng Press Volume 0 1.0005301 0 0 0.68631944 0.46180304 1142.8674 1000 1 -0.2948784 0 0.39107738 1.1626002 1268.8767 2000 1 -0.34841619 0 0.3375396 1.1178514 1300.3744 3000 1 -0.45198006 0 0.23397572 1.5104251 1319.535 4000 1 -0.4930904 0 0.19286538 1.5054789 1359.7954 5000 1 -0.49437088 0 0.19158491 1.5038965 1397.2548 6000 1 -0.4538845 0 0.23207128 1.2100734 1429.6759 7000 1 -0.46715598 0 0.2187998 1.1832386 1441.9733 8000 1 -0.4490541 0 0.23690168 1.1504605 1441.328 9000 1 -0.41648732 0 0.26946847 1.1453723 1437.0673 10000 1 -0.3776725 0 0.30828328 1.080226 1434.3847 11000 1 -0.4189651 0 0.26699069 1.0496379 1435.2496 12000 1 -0.39688957 0 0.28906621 1.0443611 1440.7218 13000 1 -0.38977976 0 0.29617602 1.0309823 1460.2618 14000 1 -0.38124839 0 0.30470739 1.0195507 1463.0566 15000 1 -0.35208681 0 0.33386897 0.93784921 1466.2431 16000 1 -0.41112084 0 0.27483495 1.0717681 1465.3625 17000 1 -0.36742687 0 0.31852892 1.0452766 1466.8819 18000 1 -0.38418683 0 0.30176896 0.94933535 1464.1674 19000 1 -0.38168345 0 0.30427234 0.97892386 1457.3935 20000 1 -0.37778426 0 0.30817153 1.0205159 1452.8383 21000 1 -0.3778136 0 0.30814218 1.07933 1449.0972 22000 1 -0.36663586 0 0.31931993 0.93798261 1452.0117 23000 1 -0.39885464 0 0.28710115 1.0286456 1449.9107 24000 1 -0.40766765 0 0.27828813 1.138272 1451.4717 25000 1 -0.36180623 0 0.32414956 0.91494742 1464.0945 Loop time of 8.50579 on 4 procs for 25000 steps with 769 atoms Pair time (%) = 0.268214 (3.15331) Neigh time (%) = 0.0587357 (0.690537) Comm time (%) = 3.79294 (44.5924) Outpt time (%) = 0.297142 (3.49341) Other time (%) = 4.08876 (48.0703) Nlocal: 192.25 ave 244 max 151 min Histogram: 1 1 0 0 0 1 0 0 0 1 Nghost: 43 ave 45 max 41 min Histogram: 1 0 0 0 0 2 0 0 0 1 Neighs: 399.25 ave 566 max 263 min Histogram: 1 1 0 0 0 0 1 0 0 1 Total # of neighbors = 1597 Ave neighs/atom = 2.07672 Neighbor list builds = 1638 Dangerous builds = 0