Dear all,
I used fix evaporate command to delete molecules in a tube sealed by a piston under a constant pressure. Although the temperature output by thermo_style seems correct, the temperature shows a distribution along the tube with an increasing trend after the deletion of liquid molecules. The temperature increases from the dead-end of the tube all the way to the sealing piston.
Is this reasonable or how should I avoid this? The code about calculation is attached below.
fix Fadd Piston aveforce ${force} 0 0
fix frezPiston Piston setforce NULL 0 0
fix WallNVE allwall nve
fix LiqNVT2 Liq nvt temp${temperature} {temperature} (150*dt)
compute T_Liq_modi Liq temp
compute_modify T_Liq_modi dynamic/dof yes
fix_modify LiqNVT2 temp T_Liq_modi
fix avg_T_Liq_modi Liq ave/time 1 {NthermoFreq} {NthermoFreq} c_T_Liq_modi
thermo ${NthermoFreq}
thermo_style custom step f_avg_T_Liq_modi atoms
run_style verlet
timestep 1
reset_timestep 0
region bath block 100.0 INF INF INF INF INF side in
fix delete_Liq Liq evaporate 5000000 4000 bath 55555 molecule yes
comm_style tiled
fix tiled_division all balance 1000 1.1 rcb
density along x
compute dens_Liq Liq chunk/atom bin/1d x lower ${binx} units box bound x 0.0 400.0
fix dens_Liq_out Liq ave/chunk 2 25000 50000 dens_Liq density/number ave one file dens_Liq.dat
temperature aloing x
compute Temp_Liq Liq chunk/atom bin/1d x lower ${binx} units box bound x 0.0 400.0
fix Temp_Liq_out Liq ave/chunk 2 25000 50000 Temp_c10 temp norm all file Temp_Liq.dat
run ${Totstep2}