# water flow in nanochannel

hi dear users , for simulating of water flow in nanochannel with metal walls(poiseuille flow) i want to set
the water flow on 300K and the walls be fixed with no moving . for this perpose i must to set velocity of walls
velocity walls set 0.0 0.0 0.0 , and the flow : fix forflow flow addforce 0.5 0.0 0.0 .
so the walls group is fixed with no moving and i want to have 300K , but the output temperature in log is been shown 222K ,
i think that this is for no moving of wall group , and the 300K for flow group distributes on flow+walls group .
i want to have fixed walls with no moving + 300K temprature for all group of system(walls+flow) .
what can i do for solve the problem ? please give me propose thank all of you dears .

but the output temperature in log is been shown 222K

The default thermo output is the temp of all atoms.
If you don’t want that, then create an output with the temp
of the flow atoms. See the thermo_style custom and thermo_modify temp
commands.

Steve

hi dear users , for simulating of water flow in nanochannel with metal walls(poiseuille flow) i want to set
the water flow on 300K and the walls be fixed with no moving . for this perpose i must to set velocity of walls
velocity walls set 0.0 0.0 0.0 , and the flow : fix forflow flow addforce 0.5 0.0 0.0 .
so the walls group is fixed with no moving and i want to have 300K , but the output temperature in log is been shown 222K ,
i think that this is for no moving of wall group , and the 300K for flow group distributes on flow+walls group .
i want to have fixed walls with no moving + 300K temprature for all group of system(walls+flow) .
what can i do for solve the problem ? please give me propose thank all of you dears .
i want a fixed wall with steady temperature 300K , which of these command i should use ?

·

fix aveforce − set force on particles to average value, so they move together

·

fix setforce − set force on particles to a value, e.g. 0.0

·

fix freeze − freeze particles for use as granular walls

·

fix nve/noforce − advect particles by their velocity, but without force

·

fix move − prescribe motion of particles by a linear velocity, oscillation, rotation, variable

neither.

if you want atoms to have a temperature (i.e. move somewhat freely and
randomly) but not leave their (average) location, you need to use fix
spring/self.

axel.

“Fixed” means they don’t move. How do atoms that
don’t move have temperature?

Steve