Query about pressure and heat flux calculation in Poiseuille flow.

Hi all,
I am doing a Poiseuille flow simulation using two solid walls (platinum) and Argon as fluid atoms. I have two questions regarding that.

  1. To measure stress tensor across the channel (divided into many bins), I use compute stress/atom and fix ave/spatial.
    If I have to measure pressure across the same channel , will it be sufficient to add the diagonal components of stress tensor which I get from above and divide it by 3 times the volume of fluid domain? I can see from the manual that using stress/atom with compute reduce will give us global pressure value but I need to measure the pressure across the channel (at each bin).

  2. For the same case, if I have to measure heat flux across the channel, can I use the commands compute heat/flux and assign an atom_style_variable (eg., hf_x, hf_y, hf_z) and then use fix ave/spatial to average that atom_style_variable? Also, the kinetic energy contribution used by heat flux is considering the atom velocity as it is but not the streaming velocity subtracted out from it (This facility is available in compute stress/atom now). Is there any other way to measure heat flux for this case?
    Can anyone please give their comments on this?

Thanks in advance.

these are not really LAMMPS questions, but conceptual

Qs about the meaning of pressure and heat flux.

So the mail list is not ideal for that, but maybe you’ll
get lucky.