LAMMPS (7 Jul 2009) # 2-d LJ flow simulation 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 20 0 10 -0.25 0.25 create_box 3 box Created orthogonal box = (0 0 -0.321089) to (25.6871 22.2457 0.321089) 2 by 2 by 1 processor grid create_atoms 1 box Created 420 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 60 atoms in group lower region 2 block INF INF 8.75 INF INF INF group upper region 2 60 atoms in group upper group boundary union lower upper 120 atoms in group boundary group flow subtract all boundary 300 atoms in group flow set group lower type 2 60 settings made for type set group upper type 3 60 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 # Couette flow velocity lower set 0.0 0.0 0.0 velocity upper set 3.0 0.0 0.0 fix 3 boundary setforce 0.0 0.0 0.0 fix 4 all enforce2d # Poisseuille 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 -1.0 0.0 #fix 6 flow addforce 0.5 0.0 0.0 #fix 7 all enforce2d # Run timestep 0.003 thermo 500 thermo_modify temp mobile dump 1 all atom 50 dump.flow run 10000 Memory usage per processor = 1.67714 Mbytes Step Temp E_pair E_mol TotEng Press Volume 0 1 0 0 0.71190476 0.5232453 571.43371 500 1.0951876 -0.33403931 0 0.44562996 3.2508527 571.43371 1000 1 -0.3731019 0 0.33880286 2.856717 571.43371 1500 1.0366879 -0.36031105 0 0.37771198 3.0202123 571.43371 2000 1 -0.41052951 0 0.30137525 2.8657415 571.43371 2500 1.1228466 -0.37043294 0 0.42892693 2.9450302 571.43371 3000 1 -0.37926849 0 0.33263627 2.5756937 571.43371 3500 1.0426371 -0.46446342 0 0.27779493 2.6309178 571.43371 4000 1 -0.43996746 0 0.2719373 2.7108953 571.43371 4500 0.97471021 -0.43234275 0 0.26155809 2.4118441 571.43371 5000 1 -0.38709789 0 0.32480687 2.6100243 571.43371 5500 1.0551901 -0.42334943 0 0.32784545 2.4333785 571.43371 6000 1 -0.45014484 0 0.26175993 2.5188073 571.43371 6500 1.0439428 -0.46442749 0 0.27876034 2.2352899 571.43371 7000 1 -0.42616126 0 0.2857435 2.4560563 571.43371 7500 1.0680429 -0.41282904 0 0.34751579 2.5532595 571.43371 8000 1 -0.44461273 0 0.26729203 2.1838508 571.43371 8500 1.0212571 -0.43065547 0 0.29638229 2.2193889 571.43371 9000 1 -0.43364252 0 0.27826224 2.4244927 571.43371 9500 1.1269004 -0.48721451 0 0.31503125 2.3601218 571.43371 10000 1 -0.50814904 0 0.20375572 2.3234126 571.43371 Loop time of 3.45458 on 4 procs for 10000 steps with 420 atoms Pair time (%) = 0.0726623 (2.10336) Neigh time (%) = 0.0228513 (0.661479) Comm time (%) = 2.63741 (76.3452) Outpt time (%) = 0.164288 (4.75566) Other time (%) = 0.55737 (16.1343) Nlocal: 105 ave 116 max 93 min Histogram: 1 1 0 0 0 0 0 0 0 2 Nghost: 40.25 ave 43 max 36 min Histogram: 1 0 0 0 1 0 0 0 0 2 Neighs: 238.75 ave 307 max 175 min Histogram: 2 0 0 0 0 0 0 0 0 2 Total # of neighbors = 955 Ave neighs/atom = 2.27381 Neighbor list builds = 967 Dangerous builds = 0