LIGGGHTS® - User Forum

Hi all!

I have encountered the following problem with the energy equation in my simulation:

I am running the simulation with a constant particle temperature (for testing purposes). At a certain point, I get some "Not a Number" (nan) errors. The simulation goes on smoothly because the governing equations of movement are not affacted, it's just not possible to postprocess the temperature and heat transfer of the particles because the arrays are corrupted.

The thermo output looks like that when the error occurs:

Hi all.

I'm trying to install the voro++ package in order to enable computation of voronoi volumes of particles. However, the link for the source code provided on the LIGGGHTS documentation page seems to be broken (http://math.lbl.gov/voro++/download). Please tell me where I can find the source code.

Thanks.

Joel

Hi,

I am facing problem of particles passing through wall. I am simulating case where, particles are rotated in a container using rotating impeller. This impeller (rotating wall) is very close (5mm) to the stationary wall of container. There are two types are particles (with 1.5mm diameter and with 7mm).

When impeller is rotated, particles pass through wall. Smaller particles escape through wall more than larger particles.

Hello everyone,

In my simulations, I am using the union command to obtain a cubical region as region domain and, subsequently a cubical simulation box:
In my code I have the following regions(s):

Hello everybody,

I am inserting some atoms in a mesh/tet region and then fixing the body as rigid.
I would like to move this rigid body but, when using fix move, I get the warning:
"One or more atoms are time integrated more than once"
that gives unexpected results on the outputs I am calculating (e.g. forces on a mesh).

fix motion bottom_atoms move linear 0.01 0.0 0.0

Hi all,
I wanna create a champs pressure harmonic on LIGGGHTS and define the pressure of a surface random. Can i do it?
I created some files cads 3D and input in LIGGGHTS, How can I do to move all CADs according to different ways (linair, wiggle...)?
Best regards!
Vu

I am gonna to use multisphere commands in LIGGGHTS-PUBLIC, since public version only support serial single processor. So whether it will caculate faster if I build LIGGGHTS-PUBLIC with dummy MPI library in STUBS, and does the compiler(g++,mpic++,icc) I choose have effect on caculating speed?

Greetings to all of you,

I was running a simulation in liggghts, and this message appears:

Mesh output: element id 100384 (line 702690) has 6 neighs, but only 5 expected

It appears several times but with other elements, and in the end, this error message appears:

ERROR: Mesh output: elements 164318 and 163297 (lines 1150228 and 1143081) are duplicate
ERROR on proc 5: Fix mesh: Bad mesh, cannot continue. You can try re-running with 'heal auto_remove_duplicates' (../surface_mesh_I.h:468)

what is the meaning of the 6 neighs, but only 5 expected?

Hi guys,

I have a question.

I am running simulations that needs to be constrained in the z axis and periodic in x and y.
Since I am working with high volume fractions (higher than 0.7), I use the particletemplate/sphere command with an initially low volume fraction, then I compress the box to higher it.
This compression has to preferrably be isotropic (https://www.comsol.nl/model/isotropic-compression-with-cam-clay-material... - for more info).

Hi all,

I am getting following error while using wall/reflect function.

ERROR: Invalid fix style: "wall/reflect" (modify.cpp:820)

The command written is

fix walls all wall/reflect xlo EDGE ylo EDGE zlo EDGE xhi EDGE yhi EDGE zhi EDGE units box

I am using liggghts 3.3.0 version.

NOTE: The idea behind using wall/reflect is to avoid particles crossing wall. The wall is already defined as granular wall using fix/gran.

Appreciate your help in resolving this.

Thanks
Tuks.