LIGGGHTS® - User Forum

Dear Liggghts developers,

is there a PDF documentation of LIGGGHTS available, that I missed somehow at this website.

The reason why I ask is, the finnie-wear.pdf looks like an extract of a larger documentation and I wanted to check the reference, which is given for the Finnie erosive wear model.

With kind regards,
Thomas Wagner.

Hi,
I want to dump force on particles with following commands but it prompts an error. The statements are:
.....
compute 2 all pair/gran/local force
.....
dump dmp3 myGroup local 1000 force,txt c_2[1] c_2[2] c_2[3]
................
When i run the simulation, the following error stops my simulation:

ERROR: Dump local compute does not calculate local array

Please anybody guide me, thanks in advance...
Best,
Ram

Hi!
How can i print the instantaneous time of my simulation in my dump file.Can anybody help?
Thanks
sajjad

Hi,
I am pouring small particles in simulation box containing one big particle, during pouring I get this message many times:
INFO: more than 255 touching neighbor atoms found, growing contact history.

After a few timesteps my system slows down and stops working. Can anybody tell me about the problem?
Thanks,
Ram

I'm running a simulation in which a bin is initially filled with equal masses of two different particle types (identical properties except radius), and then opened at the bottom to allow the particles to pour out. Can anyone help me figure out how to get the code to print out the number of each particle type remaining (or equivalently, the mass) using the thermo command?

Does anyone know of a convenient way to create a rotating pour stream? I have an application where I'd like to insert particles into a tank (roughly a cylinder along z-axis) as a fairly high speed stream coming from a nozzle (more or less a point source) inside the tank, but the nozzle rotates about the z-axis creating a ring-like spray pattern.

I'm aware of the gimbal demo simulation posted at this board, and in a pinch, that might work, but I'm afraid it might be difficult to get the right kind of dynamics coming out of the tube.

Thanks,
Chris

Hi Everyone

(I wanted to post the information below (and some more pictures) as part of the original "Wear prediction" topic, but the option to attach files was not further available. That is the reason I start this topic as a follow-up. Is there a better way?)

Further to the previous postings on this topic:

I dont think the problem is in Paraview. I did the following:
* I ran the chute_wear input file (in.chute_wear) on v1.2.1-beta and on v1.2.2-beta
* I used the output file "dump99800.vtk" from both above versions of LIGGGHTS to make attached image files that:

Hi,
Restart2data file in tools is not compatible with LIGGGHTS. It gives following error message:

eading restart file ...
WARNING Restart file version does not match restart2data version
restart2data version = 15 Jan 2010
ERROR: Invalid flag in force fields section of restart file 1747942004

I want to convert restart file into data file. Can anyone help me?

Thanks in advance...
Ram

Hi Everyone

I dont know if this problem is a post-processing or a LIGGGHTS problem. I hope this is the right forum.

I ran the "chute_wear" example in (LIGGGHTS 1.2.1). During visualizing the results in Paraview, I get an error which looks like the wear prediction function does not work right.

I show in the attached 3x files a Paraview view of the model from above (at the same timestep for all 3x files):
- "wear.png"
- "shear.png"
- "pressure.png"

Looking at "wear.png", it appears that:

Hi, Christoph,
I read some papers about Janssen's equation. I have noticed that the friction angle of wall is involved in this equation. i know there is a command to define coefficient of friction, e.g. ' fix all property/global coefficientFriction peratomtypepair 1 0.7 ' , but as i understand, this 'coefficientFriction' should be for particles, so, how could i define coefficient of friction for wall?

thanks,

adabubu