LIGGGHTS® - User Forum

Hi Everyone

While running my program, after some timesteps, the particles tend to move away from the outer areas as shown in figures. why is it that I am not getting a good composition?

Also the particles are not settling down properly. What should I do about that?

I am attaching my input file also

Regards
Hari

Hi everyone,

After running my program with insert/pack, in the visualisation majority of the particles tend to stick to quadrant region out of the total insertion region defined. I haven't been able to debug the mistake.

Can anyone help me?

I am attaching the input file and log file along with the pics of the result.

Regards
Hari

Dear community,

I am simulating powder particles with dipole moments in the gradient field. That are DIPOLE and MISC packages. In the 3.2 LIGGGHTS version they were cut out. Is it possible to somehow use them? Or the only way to use 3.1.0 version?

Faithfully yours,
Oksana.

Hi,

Hello,

I'm creating a simulation with CFDEMcoupling, but I think this is more of a LIGGGHTS question. My goal is to have a tube (cross-section in XY, length in Z) with a vertical fluid flow in the Z direction. I'm inserting particles in the tube, which may drift to the top. I would like to delete the particles when they get "stuck" to the top wall. I've put in two delete_atom commands, but neither seems to be working the way I expect them to (or at all). Here's the code:

in.liggghts_init

Hi everyone,
I'm trying to analyse the packing fraction after pouring steel pellets into a container. Is there an inbuilt tool in liggghts which computes packing fraction as a function of distance from the origin (or any other reference)?

Thanks for the help.

Joel

Hi all.
I'm pouring steel pellets into a container. When I set the young's modulus to 2.1 e11 , the pellets seem to go right through the wall, which I have created using fix wall/gran ( i.e. fix xwalls1 all wall/gran model hertz tangential history primitive type 1 xplane -0.1 limitForce 'on' ).
The pellets don't go through the wall if I lower the young's modulus to around 2.1 e9
Can someone explain why this is happening?

Thanks

Joel Martis

Hi all,
I'm trying to simulate pouring of particles into various containers. By default, there are only two geometries available (cuboid and cylinder) in the fix wall/gran command. How do I create more complex geometries? Is there an open source software to create stl files which I can import using fix mesh/surface? This would then enable me to create complex geometries.

Thanks for the help.

Joel Martis

I am going through installation tutorial as mentioned in "http://www.cfdem.com/installation-tutorial" but in second step where i have to install openmpi by giving command "sudo apt-get install openmpi openmpi-devel" it does not get installed. It says:

Reading package lists... Done
Building dependency tree
Reading state information... Done
E: Unable to locate package openmpi
E: Unable to locate package openmpi-devel

What should I do?

I am working on Ubuntu 14.04LTS 64bit operating system

Hello, everyone,

I am trying to add the Van der Waals forces in LIGGGHTS 3.2.1. The easiest way should be using the L-J potential. However, the L-j model is not available in the new Version of LIGGGHTS 3.2.1 any more. Could somebody tell me, how can I implement such contact loss forces in LIGGGHTS 3.2.1 without the potential, or is it possible to compile the solver with L-J potential model?

Many thanks!

Zhen