Hello Everyone,
I am trying to simulate the motion of granular particles in a microchannel incorporating the DEM collisions and Fluid-drag forces on each particle.
I wanted to ask is there a way to incorporate Brownian Motion aswell?
I have read that Fix langevin was previously used by LAMMPS that can code Brownian motion in particles but i did not find this feature in LIGGGHTS.
Alternatively i found fix rigid langevin command in LIGGGHTS can do such a thing but i am not sure how to incorporate that into script which already does time integration via fix nve/sphere.
Please guide
Regards,
Noman Yousuf
mschramm | Thu, 08/13/2020 - 23:37
velocity command using random variable?
Hello,
you could try the following:
variable brownX atom random(-1,1,randSeedX)
variable brownY atom random(-1,1,randSeedY)
variable brownZ atom random(-1,1,randSeedZ)
velocity all set v_brownX v_brownY v_brownZ
I believe this should generate a new random number each time the variable is called. Be sure to use a different seed for each variable. (I have not tried this.)
If this does not work, one should be able to alter the fix_addforce files to create one that does Brownian motion. Instead of acting on the forces, you would act on the velocities.