How to apply periodic boundary condition on a inclined plane

Submitted by naren on Mon, 02/23/2015 - 07:05

Dear All,

I want to study the rheology of granular particles flowing on a inclined plane. Here, i want to apply periodic boundary condition (PBC) along length and width of the inclined plane. When i applied PBC for this system, it is taking the PBC for the simulation box (cube) not for the inclined plane. Can someone please help me how can i apply PBC on a inclined plane?

Many Thanks,

Narendra

JoshuaP | Mon, 02/23/2015 - 09:34

Use the xy-plane and instead of rotating the plane just rotate the gravity vector. Hope that helps.

regards
Joshua

naren | Mon, 02/23/2015 - 13:32

But in my simulation, i am using a rough base (stationary particles). On rough base, i want to study the gravity driven flow of granular particles. Can we rotate the simulation box such that inclined plane and simulation box are on the same axis?

Any help will be much appreciated.

Thanks,
Narendra

JoshuaP | Mon, 02/23/2015 - 14:34

Ok, but why you cant just rotate the gravity vector instead of the box? Hold the box and rotate the gravity vector, than you can observe the gravity driven flow.
Try:

variable alpha equal 10
variable y equal sin(${alpha})
variable z equal cos(${alpha})
fix grav all gravity 9.81 vector 0 $y $z

where alpha is the inclination angle.

naren | Tue, 02/24/2015 - 13:06

Thanks for your time JoshuaP. Still i am unable to apply the periodic boundaries on a inclined plane. Even after changing the gravity vector, still PBC is showing on simulation box not on inclined plane. Is there any similar examples which i can follow? (or) Can we tilt the simulation box to the same angle as the inclined plane?

Again many thanks for help

Regards,
Narendra

jtvanlew | Tue, 02/24/2015 - 18:11

Is your only issue that it doesn't _look_ like it's on an inclined plane? Changing the gravity vector changes the behavior of the system to act as if inclined but obviously not the visualization of the geometry.

If you're obsessed with making it appear inclined, you could try using a triclinic region for your system such that the y-z surfaces are angled. I've never tried that so I don't know if that would be ideal but could be an option.

jon

naren | Mon, 03/02/2015 - 10:23

I was confused with the gravity vector. It is working fine now.

Thanks,
Narendra