Height depended lattice spacing

Hello all,

I’m a PhD student at the Delft University of Technology.

I’m using an OpenFOAM-LAMMPS combination called sediFoam for liquid-solid CFD-DEM simulations (I know LIGGGHTS and CFDEM exist but this code serves my needs better).

I’d like to create atoms on a lattice with a spacing that that increases along the z-dimension of my domain. Do any of you have a clever idea of how to do this? The domain is a simple rectangular box with periodic boundaries in the x and y planes walls in both the z planes.

Thanks in advance for your feedback.

Hello all,

I'm a PhD student at the Delft University of Technology.

I'm using an OpenFOAM-LAMMPS combination called sediFoam for liquid-solid
CFD-DEM simulations (I know LIGGGHTS and CFDEM exist but this code serves my
needs better).

I'd like to create atoms on a lattice with a spacing that that increases
along the z-dimension of my domain. Do any of you have a clever idea of how
to do this? The domain is a simple rectangular box with periodic boundaries
in the x and y planes walls in both the z planes.

how about something like this?

units lj
lattice sc 1.0
region box block 0.0 10.0 0.0 10.0 0.0 40.0
create_box 1 box

variable idx loop 0 10
variable spacing index 0.2
variable offset equal v_idx*v_spacing

label layer

lattice sc 1.0 origin 0.0 0.0 \(v\_idx\*v\_offset%1\.0\) region layer block INF INF INF INF (v_idx+v_idx*v_offset-0.1)
$(v_idx+v_idx*v_offset+0.1)
create_atoms 1 region layer
region layer delete

next idx
jump SELF layer

write_dump all image box.pnm type type size 1080 1920 zoom 1.8

groetjes,
      axel.

cool - this answer is so clever, I included it on this page:

http://lammps.sandia.gov/user.html

Steve