LIGGGHTS® - User Forum

Hi Chris,

I tried to reconstruct the CFD results of "twoSpheresGlowinskiMPI" case, however it seems not possible right now, due to the refined mesh generated during the run.

So i thought run the case with only 1 core will solve this issue, but with dataExchangeModel twoWayMPI the solver does not allow running on single core, even I changed the

mpirun -np $nrProcs $debugMode $solverName -parallel 2>&1 | tee -a $logpath/$logfileName

to

$solverName > $logpath/$logfileName

I need to know is there any command or tactic/solution for adding stress (psi) to the one surface/edge of a simulation domain (box) which is poured by particles?
I have attached a picture that can help you to understand me.

Thank you for your help in advance,

Sincerely,
Rasoul

Hello,
I want to simulate the flow of lubrication oil in bearings using the SPH-Method.

So I need an inner and outer ring that rotate around the origin(0,0,0) in opposite direction and several rolling elements that rotate around their own axis. And at the same time I need a rotation gravity vector, that rotates with the same angular velocity as the outer ring, using the gravity gradient command.

Hi,
I want to use periodic boundaries in order to minimize simulation time. But I don't know how to get things done correctly.

I'm trying to set up a volume of particles, then move the particle with ID 1 to a position above the volume, change it's diameter and density, and let it drop. Problem is it disappears.

I make the volume separately (create.txt), and then in the main file that (drop.txt) that file is read in and I use the following:


...
run 10

set atom 1 x 0 y 0 z 0 vx 0 vy 0 vz 0
set atom 1 diameter 0.03
set atom 1 density 4865

run 60000

Can I define a column other than the sphere in the public domain of LIGGGHTS? If yes, how? Is the multisphere function for complex geometry available in LIGGGHTS?

Hi

I asm quite novel to LIGGGHTS and I created my first simulation. I only selected to create 500 particles with radius 10 mm.

I get this error when running the simulaiton : Error too many atoms sorting bins

cheers
michele

Hi

I asm quite novel to LIGGGHTS and I created my first simulation. I only selected to create 500 particles with radius 10 mm.

I get this error when running the simulaiton : Error too many atoms sorting bins

cheers
michele

Hi Chris,

I recently modified the original cfdemSolverPiso from PISO to PIMLE (merged PISO-SIMPLE) loop, i.e. supporting adjustable timestep for CFD solver. It helps speeding up the calculation when CFD domain contains millions of cells.

In priciple the new CFD-DEM solver works fine, and if the CFD "adjustTimeStep" option is turned off, the solver is more or less same to the original one. However, there are some remaining issues:

"LIGGGHTS INSTALLATION GUIDE FOR UBUNTU 12.04 LTS, 13.04 LTS, 14.04 LTS, 15.10, LTS 16*, LTS 18*"
NOTES: 1. This documentation was written long back since when several changes have been made by LIGGGHTS developers that made the installation relatively easy. However, to have backward compatibility those outdated instructions for installation are still available but are deprecated with special notes.