As we know Lammps doesn’t have any thermal wall model. So if one wants to have a wall with a constant temperature he should use atomistic walls.
I want to calculate thermal conductivity of a liquid confined in two solid walls (up wall and down wall).
I want to use NEMD method so i have to set the upper and lower walls in two different temperature (by temp/rescale command). then i have to calculate the energy that “fix temp/rescale” added to (or absorbed from) walls . then calculate heat flux. and calculate thermal conductivity by dividing heat flux to temperature gradient. I did the work but the result was not correct. I think the main reason could be raised from modelling walls.
I used atomistic walls, LJ potential between wall atoms and a spring with “fix spring/self” command. The reason of using an spring is to hold wall atoms about their original position. But as we know in real world there is no spring attached to atoms and the energy of springs are not real. So i think using springs cases false “flux calculation” and false “thermal conductivity” calculation.
If my gusse is true then how can i model a wall with constant temperature with Lammps while there is no “thermal wall” model provided in Lammps?