LIGGGHTS® - User Forum

Dear all,

i'm simulating granular particles flowing through a pipe. Does LIGGGHTS provide a method to count particle-particle collisions per timestep?

Best Regards
Felix

I am just wondering that is there any way to automatically adjust the timestep in the simulation based on the size of newly generated/inserted particles. One such way is to use fix dt/reset but in that the impornat keyword is XMAX which seems difficult to produce.

Hi,

when I am trying to use the compute inertia/molecule on a molecule defined by fix rigid, I receive an error message like:
"ERROR: Invalid compute style (modify.cpp:883)"

I compiled LIGGGHTS together with the MOLECULE package and I am wondering why this would be an invalid compute style?

My files are attached to this post.

Best regards,
MiRa

Hi Colleagues,
I have problems with the .stl geometry rencently. I used SolidWorks to create
3D geometric models and then save them in .stl format as the mesh walls. However,
when I viewed the geometry with Paraview, they looked like solid. I noitced in the tutorial examples, all the geomery are surface mesh (please see the attached figures). the example.png is from the tutorial example, and the myexample.png shows my own example.

I failed to save plane/surface in the solidwork as .stl.

Hello,

I'm thinking about how to choose the optimal time increment for my simulations. I set up a very simple testcase in order to study the behaviour of contact interaction between particles and STL-geometries, defined as wall.
Video: http://www.youtube.com/watch?v=IBf3vUwHh-w
First, I calculated the timestep as provided by many posts in this forum with the formula dt = 0.2*dt_rayleigh:
r = 0.005
rho = 8000
Y = 5e6
nu = 0.3
G = Y/(2*(1+nu)) = 1923076.92

Hello,

Hi all,

I am trying to do simulation on a rotary drum, simulating the rotation by changing the gravity force. I hope you could help me. Here is my code:

atom_style granular
atom_modify map array
boundary p p p
echo screen
newton off

units si

communicate single vel yes

region reg block 0 2.4 0 0.314 0 0.314 units box
create_box 1 reg

neighbor 0.02 bin
neigh_modify delay 0

Hi,

I define a wall with the stl style, and I want to change the normal direction of this wall. Can anyone tell me how to do it ?

Thanks

I have the Ubuntu makefile for Opensuse 12.3 but the cluster system is on Suse 11. Can anyone please provide me the working makefile for Suse 11

Dear all,

i'm fairly new to LIGGGHTS and i'm simulating particles flowing trough a pipe with periodic boundary conditions in flow direction. I would like to count the particles per iteration which are passing my periodic boundary. I'm able to do so by dumping particle positions to a file and check the passing by a script.
I was wondering if there is a way to do so using LIGGGHTS?

Best regards
Felix V.