LIGGGHTS® - User Forum

Hi guys.

I met a problem when I was compiling LIGGGHTS on my PC(i5-3470, memory 4G ). After checking the settings with "cfdemSysTest", I began "cfdemCompLIG", it went smoothly at first, but when compiling certain **.cpp file, the screen was frozen. After long time(about 20 minutes), this situation stopped and the compling process went on, but there was no lmp_fedora_fpic in the src directory after the compiling process finished. Does anyone meet the same problem? Is that because the hardware of my PC too low?

Hi,

I am trying to simulate a system with two type of particles, the firsts are rectanuglar, and the others are normal spherical particles. The problem is that when I put all particles in my system, only rectangular particles move.
Here is my script, i home someone could help

thank you in advance for your help

Hi All,

Could anyone please discuss the reasons that particles go out of domain during simulation? The volume could increase quickly if particles are not in the domain.

Thanks!

Kun

Dear Colleagues,
My simulation ended up with an erro:
Mesh elements have been lost (multi_node_mesh_parallel_I.h:613)

Does some one know what might be the reason? Thank you

Cheers,

zilin

Dear colleagues,

Recently I am repeating a same simulation with different cores (1-128 cores ) with our HPC.

I find two things that are strange to me:

1. When the number of the cores changes, the number of the particles that are created from the input script is different, the difference is not big (a few to ten particles).

Is this a bug of the liggghts or i set wrong parameters?

I imported my stl geometry (created using solidworks) into Paraview. I found the Origin of this stl geometry was not the same as bofore being imported. Did someone come across this problem? My antoher question is how the coordinates of the CAD geometry is read in the Paraview?
Thank you,

ZYan

I want to simulate a particle inlet boundary with given solid volume fraction and velocity, i.e the solid volume fraction and velocity in this boudary region is always fixed. I defined a region above the boundary, calculated the massrate, and used the insert/rate/region command. Since I want to keep the solid volume fraction fixed, should I set the insert_every to be 1?
I found many warnings come out.

Hi everyone,

I need to make a fluid-particle simulation but I can't use CFD for the fluid because of the length scale of my particles interactions. According to this, i'm looking to make a mesoscale coupling between SPH and DEM. I know that LIGGGHTS has both models but is it possible to couple them?

Thanks in advance.

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.