How to simulate a poiseuille flow without adding the solid wall

Thank you for your prompt reply. What about using the “fix wall/lj126” command? It seems that this command can mimic the solid wall. Isn’t it?

Thank you for your prompt reply. What about using the "fix wall/lj126"
command? It seems that this command can mimic the solid wall. Isn't it?

please explain why it should?

as i said, your problem is that you don't consider the physics of your
problem properly. or to put it simply: what is it *exactly* that
causes the atoms near the boundary to slow down?

axel.