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) 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 -0.47091627 0 0.21568971 1.5138977 1319.4646 4000 1 -0.53350497 0 0.15310101 1.4944821 1368.5881 5000 1 -0.46292485 0 0.22368114 1.2007151 1416.2864 6000 1 -0.4840293 0 0.20257668 1.1994107 1436.0523 7000 1 -0.45403921 0 0.23256677 1.1708541 1437.7219 8000 1 -0.41159332 0 0.27501266 1.1550046 1443.6922 9000 1 -0.41547978 0 0.2711262 1.0869774 1444.7435 10000 1 -0.38872511 0 0.29788087 1.0859399 1448.9027 11000 1 -0.39658436 0 0.29002162 1.0406362 1447.3119 12000 1 -0.39586595 0 0.29074003 1.0949165 1449.8724 13000 1 -0.39435825 0 0.29224774 1.0817864 1452.2757 14000 1 -0.36990161 0 0.31670437 1.1476876 1452.7226 15000 1 -0.38474219 0 0.30186379 0.98095711 1451.4975 16000 1 -0.41415615 0 0.27244983 0.95880772 1453.0613 17000 1 -0.39042525 0 0.29618073 1.1420924 1454.0452 18000 1 -0.36705814 0 0.31954784 0.93081775 1467.6296 19000 1 -0.37593163 0 0.31067436 0.93215485 1460.1912 20000 1 -0.4112996 0 0.27530639 1.0969385 1455.308 21000 1 -0.36306488 0 0.3235411 0.98121028 1466.6771 22000 1 -0.35841364 0 0.32819234 1.0494923 1460.8771 23000 1 -0.37487432 0 0.31173166 1.0663397 1458.2961 24000 1 -0.3709832 0 0.31562279 0.98706703 1461.0666 25000 1 -0.35861879 0 0.3279872 0.98212968 1456.9008 Loop time of 7.98535 on 4 procs for 25000 steps with 769 atoms Pair time (%) = 0.271931 (3.40537) Neigh time (%) = 0.0604256 (0.756706) Comm time (%) = 3.47832 (43.5588) Outpt time (%) = 0.329306 (4.12387) Other time (%) = 3.84537 (48.1553) Nlocal: 192.25 ave 240 max 160 min Histogram: 2 0 0 0 0 1 0 0 0 1 Nghost: 43.75 ave 49 max 35 min Histogram: 1 0 0 0 0 0 1 0 1 1 Neighs: 402.25 ave 566 max 284 min Histogram: 2 0 0 0 0 0 1 0 0 1 Total # of neighbors = 1609 Ave neighs/atom = 2.09233 Neighbor list builds = 1629 Dangerous builds = 0