Dear LAMMPS users,
I have a system including two parallel solid walls that Argon gas atoms are confined between them. In this system, gas atoms can freely exchange energy with each other, and the wall’s atoms. I want to study the heat transfer between walls and gas. To do so, I duplicated the system in the Y-direction in order to have a symmetric simulation box (as it can be seen in the attached figure). I used fix Langevin to fix the temperature of the middle wall at 500 and the temperatures of the side walls at 300. I want to compute the heat flux between the walls while keeping their temperature fixed. As I have seen in the example provided in LAMMPS documentation, the heat added to the heat source and subtracted from the heat sink, supposed to have negative and positive signs, respectively. But as you can see, in the attached log-file in my case, they have both negative values. I highly appreciate if someone could tell me what I am doing wrong here.
###########################################Input file
region whole block 0 100 0 450 0 100 units box
create_box 2 whole
region Au_B block INF INF 10 19 INF INF units box #Bottom Wall
region Au_M block INF INF 220 233 INF INF units box #Middle walll
region Au_T block INF INF 432 442 INF INF units box #Middle walll
create_atoms 1 region Au_B
create_atoms 1 region Au_M
create_atoms 1 region Au_T
group AuBfix region Au_B_fix
group AuTfix region Au_T_fix
group AuMfix region Au_M_fix
group AuB_thermo subtract AuB AuBfix
group AuT_thermo subtract AuT AuTfix
group AuM_thermo subtract AuM AuMfix
timestep 0.001
#----------------------------------------------FORCE FIELD--------------------------------------------------------------
#-------------------------------------------------------Adding Ar atoms
