Using Irving-Kirkwood formalism for pressure

Hello users
I want to measure pressure for a transient flow.
In the following paper mentioned that Irving-Kirkwood formalism can be used with the peculiar velocity as the molecular velocity minus the
streaming velocity at the molecular position and averaging in short period.
“Molecular dynamics simulation of a pressure-driven liquid transport process in a cylindrical nanopore using two self-adjusting plates”
Is this possible for a transient flow?
I did not see this kind of work in any publications.
Any help for determining pressure in a transient flow will be appreciated.

You might want to elaborate on whether you want to calculate pressure (in which case see the manual - common topic on the list as well) or control some sort of pressure drop.

Yes i want to compute pressure but my system is transient and i can’t use time average ensemble for computing pressure.
I cant find any method for dealing this.
Do you know any method or someone could help?

Do you work on multi phase flows?
I am exactly working on multi phase flows with molecular dynamics and encountered with big problems for explaining my results and they need pressure magnitude to be acceptable.
Can you advice a publication that can help me for doing this?
I have a moving droplet and need to determine pressure inside that phase and outside of it.

There’s no magic bullet for converging statistics, if you don’t want to or can’t change physics, systems size, etc. The only way to do that is with more samples. I typically run multiple realizations for transient systems. You can’t rely on the ergodic hypothesis for all things.

Note that theses are just questions about how to compute expectations - not actually LAMMPS Q’s. Best of luck.