LAMMPS (15 Jan 2010) # 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) 1 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 = 1.70365 Mbytes Step Temp E_pair E_mol TotEng Press Volume 0 1.0027471 0 0 0.68849216 0.463265 1142.8674 1000 1 -0.33974838 0 0.3468576 1.3038702 1270.08 2000 1 -0.39015699 0 0.296449 1.3186607 1302.3377 3000 1 -0.46396074 0 0.22264524 1.4481728 1319.6122 4000 1 -0.55168245 0 0.13492354 1.4184455 1363.9273 5000 1 -0.4779618 0 0.20864418 1.2502404 1406.5295 6000 1 -0.47676997 0 0.20983601 1.2766303 1431.8586 7000 1 -0.44544558 0 0.2411604 1.1288416 1446.72 8000 1 -0.42622152 0 0.26038446 1.1899082 1445.0314 9000 1 -0.39979278 0 0.2868132 1.0493833 1445.9286 10000 1 -0.39956916 0 0.28703682 0.97028333 1446.191 11000 1 -0.40361686 0 0.28298912 1.057903 1449.2472 12000 1 -0.37544064 0 0.31116534 1.016674 1447.5937 13000 1 -0.36653621 0 0.32006977 1.0630025 1449.401 14000 1 -0.40246924 0 0.28413674 0.99129298 1452.1357 15000 1 -0.37910159 0 0.30750439 1.0060487 1450.2039 16000 1 -0.38445099 0 0.302155 1.0408416 1452.4736 17000 1 -0.38494791 0 0.30165807 1.0526188 1457.2931 18000 1 -0.41499692 0 0.27160906 1.025714 1457.7231 19000 1 -0.38006405 0 0.30654193 1.0261829 1456.6155 20000 1 -0.36822545 0 0.31838053 0.99877348 1458.3744 21000 1 -0.36767353 0 0.31893245 1.0565706 1459.1233 22000 1 -0.38042505 0 0.30618094 0.95242531 1460.1608 23000 1 -0.35760367 0 0.32900231 0.96609857 1462.1329 24000 1 -0.38579461 0 0.30081137 0.88542206 1456.1573 25000 1 -0.37757028 0 0.3090357 1.0053932 1459.734 Loop time of 3.20272 on 1 procs for 25000 steps with 769 atoms Pair time (%) = 0.862554 (26.9319) Neigh time (%) = 0.191959 (5.99364) Comm time (%) = 0.0474339 (1.48105) Outpt time (%) = 0.293291 (9.15756) Other time (%) = 1.80748 (56.4358) Nlocal: 769 ave 769 max 769 min Histogram: 1 0 0 0 0 0 0 0 0 0 Nghost: 42 ave 42 max 42 min Histogram: 1 0 0 0 0 0 0 0 0 0 Neighs: 1622 ave 1622 max 1622 min Histogram: 1 0 0 0 0 0 0 0 0 0 Total # of neighbors = 1622 Ave neighs/atom = 2.10923 Neighbor list builds = 1631 Dangerous builds = 0