LIGGGHTS® - User Forum

Hi,

Hi,

I have been trying to simulate particle flow through what is basically a rock impeller, which runs at approximately 1800 rpm. Particle speeds can be up to around 60 m/s, and maybe 40% of particles will fly through both the impeller walls and the outer (static) wall. Both are generated from stl files.

I have tried reducing the timestep down to 1e-7, with no noticeable improvement, and have also tried reducing the mesh spacing in the stl files.

Is there anything else I can do to improve the detection rate?

I have been trying to add a new plasticity contact model to the LIGGGHTS code. I have the formulation down but this model requires I keep track of the plastic deformation between particle-particle and particle-wall contacts. It should work similarly to the shearing array that is present in the code. However, I have been unable to add the array properly.

Hi everyone

I have written a small piece of code that converts the dump file to vtk. It works through cmd/comsole in windows and takes the standard fields in dump file i.e. id type type x y z ix iy iz vx vy vz fx fy fz omegax omegay omegaz radius. A recompilation after modifying the source code can be done if the field are different than specified.

Dear colleagues,
Do you know if it is possible to exclude ( or disable) those particles (i.e. particles in a sellected cube) from the calculation. Thank you in advace for your
help.
Cheers
ZYan

Hello all,

I was trying to install liggghts source code following the steps provided on the web. The first steps run as in the tutorial but I had problem with "Set symbolic link for LIGGGHTS" command.

Here is some commands I used and their outcomes :

which mpirun
/usr/bin/mpirun

which mpic++
/usr/bin/mpic++

mpic++ -v
gcc version 4.8.2 (Ubuntu 4.8.2-19ubuntu1)

cd /home/"user"/LIGGGHTS-PUBLIC/src
sudo make clean-all
sudo make make fedora

Hi LIGGGTHS USER, Hi Chris,

as a commercial DEM code user, I have done realistic particle simulation several years ago. However, it's difficult to modify or add new contact model for commercial software. So I want to implement this job with LIGGGHTS. I have few question concerning the proper "atom_style" for rigid body:

Test example: three non-spherical particles drop under gravity. Their initial positions are (0 0 1), (0 0 1.5), (0 0 2.0) receptively.

1) Method 1: only "atom_style sphere" is used.

Hello, So I am running simulations of a simple agitator in a bucket (see agitator pic). I am interested in calculating the torque of a spinning agitator but my results seem odd when I use tangential history on the gran/wall and pair_style fix. When I plot the f_agitator_post[6] (from everything I read, it seems that this would be the torque acting on the agitator body in the z-direction), the values jump between positive and negative 2 N-m (see tangent_history_chart). This result seems rather odd because the blade is only spinning in one direction.

Hello all,

attached to this post there are scripts I made internal heat transfer in multispherical particles the changes involve:

Hi,

I'm trying to compute the forces in one axis that acts on a mesh, while the mesh moves through particles.
My attempt was the following:
###########################################
compute forcez all wall/gran/local force
compute actforce all reduce sum c_forcez[3]

thermo_style custom c_actforce
thermo 1000
thermo_modify lost ignore norm no
compute_modify thermo temp dynamic yes
###########################################