calculating the momentum flux

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1

Dear all

in order to calculate the flux I used to integrate the velocity profile manually.
Is there a way to directly compute it?

thanks
Fahim

2

There is no context to your question.
Flux of what?

Steve

3

momentum flux

Fahim

4

I still don't know what you're talking about.
If you are using the fix viscosity command to
do Muller-Plathe, then it tallies the momentum
flux. You measure the velocity gradient by using
fix ave/spatial and the ratio gives you viscosity.
The doc page explains it.

Steve

5

thanks Steve
suppose I want to sum over all atoms velocities in a specific direction (e.g. x-component of velocities, vx), then time averaging on the resultant quantity.

Best,
Fahim

6

this will do http://lammps.sandia.gov/doc/fix_ave_spatial.html

see the examples …