region value = region-ID
region-ID = ID of region to use as insertion volume
- diam values = lo hi
- lo,hi = range of diameters for inserted particles (distance units)
- dens values = lo hi
- lo,hi = range of densities for inserted particles
+ diam values = dstyle args
+ dstyle = one or range or poly
+ one args = D
+ D = single diameter for inserted particles (distance units)
+ range args = Dlo Dhi
+ Dlo,Dhi = range of diameters for inserted particles (distance units)
+ one args = Npoly D1 P1 D2 P2 ...
+ Npoly = # of (D,P) pairs
+ D1,D2,... = diameter for subset of inserted particles (distance units)
+ P1,P2,... = percentage of inserted particles with this diameter (0-1)
vol values = fraction Nattempt
fraction = desired volume fraction for filling insertion volume
Nattempt = max # of insertion attempts per atom
@@ -53,7 +59,8 @@
Examples:
fix 3 all pour 1000 2 29494 region myblock
-fix 2 all pour 10000 1 19985583 region disk vol 0.33 100 rate 1.0 diam 0.9 1.1
+fix 2 all pour 10000 1 19985583 region disk vol 0.33 100 rate 1.0 diam range 0.9 1.1
+fix 2 all pour 10000 1 19985583 region disk diam poly 2 0.7 0.4 1.5 0.6
Description:
@@ -80,22 +87,38 @@ that the previously inserted particles fall out of the insertion
volume under the influence of gravity. Insertions continue every so
many timesteps until the desired # of particles has been inserted.
-All other keywords are optional with defaults as shown below. The
-diam, dens, and vel options enable inserted particles to have a
-range of diameters or densities or xy velocities. The specific values
-for a particular inserted particle will be chosen randomly and
-uniformly between the specified bounds. The vz or vy value for
-option vel assigns a z-velocity (3d) or y-velocity (2d) to each
-inserted particle.
+
All other keywords are optional with defaults as shown below.
+
+The diam option specifes the diameters of inserted particles. There
+are 3 styles: one, range, or poly. For one, all particles
+will have diameter D. For range, the diameter of each particle
+will be chosen randomly and uniformly between the specified Dlo and
+Dhi bounds. For poly, a series of Npoly diameters is specified.
+For each diameter a percentage value from 0.0 to 1.0 is also
+specified. The Npoly percentages must sum to 1.0. For the example
+shown above with "diam 2 0.7 0.4 1.5 0.6", all inserted particles will
+have a diameter of 0.7 or 1.5. 40% of the particles will be small;
+60% will be large.
+
+The dens and vel options enable inserted particles to have a range
+of densities or xy velocities. The specific values for a particular
+inserted particle will be chosen randomly and uniformly between the
+specified bounds. The vz or vy value for option vel assigns a
+z-velocity (3d) or y-velocity (2d) to each inserted particle.
The vol option specifies what volume fraction of the insertion
-volume will be filled with particles. The higher the value, the more
-particles are inserted each timestep. Since inserted particles cannot
-overlap, the maximum volume fraction should be no higher than about
-0.6. Each timestep particles are inserted, LAMMPS will make up to a
-total of M tries to insert the new particles without overlaps, where M
-= # of inserted particles * Nattempt. If LAMMPS is unsuccessful at
-completing all insertions, it prints a warning.
+volume will be filled with particles. For particles with a size
+specified by the diam range keyword, they are assumed to all be of
+maximum diamter Dhi for purposes of computing their contribution to
+the volume fraction.
+
+The higher the volume fraction value, the more particles are inserted
+each timestep. Since inserted particles cannot overlap, the maximum
+volume fraction should be no higher than about 0.6. Each timestep
+particles are inserted, LAMMPS will make up to a total of M tries to
+insert the new particles without overlaps, where M = # of inserted
+particles * Nattempt. If LAMMPS is unsuccessful at completing all
+insertions, it prints a warning.
The rate option moves the insertion volume in the z direction (3d)
or y direction (2d). This enables pouring particles from a
@@ -145,7 +168,7 @@ defined by the region command.
Default:
-The option defaults are diam = 1.0 1.0, dens = 1.0 1.0, vol = 0.25 50,
+
The option defaults are diam = one 1.0, dens = 1.0 1.0, vol = 0.25 50,
rate = 0.0, vel = 0.0 0.0 0.0 0.0 0.0.