Keep asking the list, especially if its a documented example. I have never run this case.
I took a look at the nemd simulation. I do not actually want to deform my box.
The output read that I had to use a triclinic box. Changing my box style to prism deforms the box; however I would like to keep the box rectangular.
I did, however, experiment with the fix viscosity command. Is there perhaps a way to use that command to obtain slip and no slip? From what I can tell, my liquid is indeed obtaining a shear force from the wall.
My code is:
2d friction simulation
dimension 2
boundary p s p
units lj
atom_style atomic
neighbor 0.3 bin
neigh_modify delay 5
create geometry
lattice hex 0.9
region box block 0 40 0 10 -0.25 0.25
create_box 4 box
mass 1 1
mass 2 1
mass 3 1
mass 4 1
atom regions
region lo-fixed block INF INF INF 1 INF INF
region hi-fixed block INF INF 9 INF INF INF
region noboundary union 2 lo-fixed hi-fixed side out
region circle sphere 20 5 0 1.5
region nocircle sphere 20 5 0 1.5 side out
#region nocircle sphere 20 5 0 3 side out
region flow intersect 2 noboundary nocircle
create 2 surfaces with asperities
create_atoms 1 region lo-fixed
create_atoms 1 region hi-fixed
create_atoms 3 region circle
create_atoms 2 region flow
#delete_atoms porosity flow 0.01 482793
LJ potentials
pair_style lj/cut 1.2
pair_coeff * * 1.0 1.0 1.2
group lo-fixed region lo-fixed
group hi-fixed region hi-fixed
group boundary union lo-fixed hi-fixed
group mobile region flow
group circle region circle
initial velocities
compute new mobile temp/partial 0 1 0
velocity mobile create 0.1 482748 temp new
velocity hi-fixed set 3.0 0.0 0.0 sum yes
velocity lo-fixed set -3.0 0.0 0.0 sum yes
fixes
fix 1 all nve
fix 2 boundary setforce 0.0 0.0 0.0
fix 3 circle temp/rescale 200 0.1 0.1 0.02 1.0
#fix_modify 3 temp new
fix 4 mobile temp/rescale 200 1.0 6.0 0.02 1.0
fix 5 all viscosity 100 x z 20
Run
timestep 0.0015
thermo 100
thermo_modify temp new
dump 1 all atom 500 dump.friction
dump 2 all image 100 image.*.jpg type type &
zoom 1.6 adiam 1.2
dump_modify 2 pad 6
run 100000
I took a look at the nemd simulation. I do not actually want to deform my box.
The output read that I had to use a triclinic box. Changing my box style to prism deforms the box; however I would like to keep the box rectangular.
Your box will remain rectangular with proper remapping. The deformation is merely a means to induce momentum transfer between period images. Such systems are “shear-periodic.” Lees-Edwards boundary conditions are intuitively easier to understand, and equivalent. Check them out.
I did, however, experiment with the fix viscosity command. Is there perhaps a way to use that command to obtain slip and no slip?
You need to ask the question of what you are trying to do. Whats the point of obtaining a result you don’t understand or necessarily require.
From what I can tell, my liquid is indeed obtaining a shear force from the wall.
Read that fix documentation more carefully.
If you can pose some well-framed specific questions, I or someone else can answer your questions more directly. But if all you’re looking to do is replicate phenomenological behaviour specific to some system, I implore you to read my previous responses on slip behaviour more carefully, and do the ground work.
Lammps is usually not intended to replicate phenomonology. You can always get a result from physically irrelevant hacking. It is a tool to simulate physical systems, where phenomological behaviour may develop as a result of physically relevant system parameters and interaction models.