[lammps-users] Dear lammps-users and developers

Comments below.


The flow group is in NVE ensemble.

The flow group is divided into divided into 15 lays. The lays are used for the statistical calculation of velocity and temperature.
The flow group is in complicated flow, and the stream velocity of different lays are different.
I want to subtract out the effect of the stream velocity to the temperature calculation of every lays.

1. I used The temp/profile or temp/com command to subtract out the effect of the stream velocity to the temperature calculation. However, I failed.
When the flow group has the stream velocity, the stream velocity will become lower and lower until zero.

Does the lammps can sovle this kind of problem?

The only way this should happen is if all the atoms in the bin acquire
exactly the stream velocity, with no additional velocity. If that is happening,
you need to figure out why - you must be driving it to do that in some manner.

2. If the temp/region command can add the new keywords to subtract out a spatially averaged velocity field before the compute of the temperature similar to the temp/profile command, this kind of problem is solved.

For example:
compute temp_1 flow temp/region liquid1 xflag yflag zflag
The new key words “xflag yflag zflag” = 0/1 for whether to exclude/include this dimension similar to the temp/profile command.

Why aren’t you just using the compute temp/profile command directly?

If you want to combine the attributes of two compute temp commands, you’ll need
to modify the source code yourself.