[lammps-users] how to create a shear flow

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1

Dear,

I want to simulate a polymer in shear flow. There may be three examples to create a shear flow in LAMMPS, they are in nemd,shear, flow sub-file respectively. But I don’t know which method is suitabe for my case.

What is the difference of nemd and flow except simulation method?

Thanks

2

What is flow sub-file?

Steve

3

In the folder of \Lammps-22May08\examples, there are three folder named nemd, shear and flow. That’s my meaning.

2008/9/18 Steve Plimpton <[email protected]>

4

In the folder of \Lammps-22May08\examples, there are three folders named nemd, shear and flow. That’s my meaning. Which method is suitable for me to simulate a polyelectrolyte in shear flow, which should compute the electrostatic interaction in simulation system.

2008/9/18 Steve Plimpton <[email protected]>

5

Wende,

Take a look at movies of the example simulations here:

http://lammps.sandia.gov/movies.html#flow
http://lammps.sandia.gov/movies.html#shear
http://lammps.sandia.gov/movies.html#nemd

That will give you a better idea about what the simulations do and which one best matches what you’re looking for.

None of these simple examples include electrostatic interactions. You’ll have to add that. I’d recommend that you take a look at the kspace_modify command with the slab option: http://lammps.sandia.gov/doc/kspace_modify.html

Paul

6

One additional note. If you want long-range electrostatics, then
you can't do that in a NEMD (tilted) box. So you should
do that with something like fix viscosity which is the Muller-Plathe
method.

See the howto section of the LAMMPS manual for more discussion
on these methods.

Steve