Hi,
I need the average weighted pressure of the particles. Using compute pressure and compute reduce of compute stress/atom I get the same result. In Liggghts this formula is used:
I am looking for something like:
using
What is the pressure Liggghts calculate with compute pressure? Why does it differ from a the pressure on the walls of the particles? Can anyone please give a hint?
Regards,
Paul
ckloss_ | Mon, 08/05/2013 - 19:45
Hi Paul,
Hi Paul,
look at the source code of fix ave/euler. Unfortunately, there is no doc yet, but I guess it's doing what you want
Best wishes,
Christoph
PaulWinkler | Sun, 08/11/2013 - 19:14
Hi Christoph,
Hi Christoph,
fix ave/euler computes cell-based averages. The cell size is a multiples of maximal cut-off. I am using periodic boundaries, so there are ghost atoms for e.g. Voronoi. Since I have just a granular but a lot of particles, cut-off is at the default value of 0.0, so the cell size would be 0? In the source code I read that number of cells should be >=1. Since I want to calculate the average of all particles, is it possible to choose cell size large enough that all particles fit in one cell?
Best wishes,
Paul
ckloss | Fri, 08/30/2013 - 15:39
Hi Paul,
Hi Paul,
>> Since I have just a granular but a lot of particles, cut-off is at the default value of 0.0
The cut-off for granular particles is the sum of the radii of the interacting pair, so the max cutoff is 2*rmax
>>average of all particles, is it possible to choose cell size large enough that all particles fit in one cell?
Should be possible, but you would need to take care to exactly align cell and domain box. If the simulation box is not completely filled with particles, then your average will be distorted
Cheers
Christoph