LIGGGHTS® - User Forum

Dear all,
I used to calculate lift force by Archimedes and the value is 0 0 5.13126e06(it equals to volume * density *9.81 ). The value is only at positive z direction. But today I update the CFDEM software. and i found the lift force calculated by Archimedes force model is not the same, x y z three direction all have values. Who can answer my confusing?

Thanks
xiaobaishu

Dear users,
Do anybody know how to use voronoi package? I compiled it in my liggghts, but it didn't work. I want to calculate the voidage. or is there any other command to calculate void ratio?

Hi

I was going through some tutorial in the website and found wear through a chute. Though it shows colors changing with time due to wear in the surface of the metal, the unit of wear is not there.

How much time it takes to develop a wear on a surface. Is it material dependent/time dependent/impact velocity dependent?

How do i understand the estimate of time of simulation to develop a wear on a surface. Any info regarding these will be helpful.

Thanks in advance.

Saprativ

Hi,

I want to insert cylinderical particles in my system and I've read all the discussions in the forum about multispheres. unfortunately they didn'e help me.
I'm not familiar about making molecules clumps and using fix rigid. can anyone help me about generating and inserting non-sphere particles step by step?
an example script could be very helpful.

BTW I have STL of my particle, but I'm not sure if it could be helpful!

Thanks,
SHG

Hello,
unfortunatly, I didn't find a good answer for this problem.
Is it possible to assign a temperature, when an particle is created.
Im trying to simulate the temperatur transition of two diffenent particletypes, while they are mixed. Therefore, the "fix heat/gran" command is not usable.
I know, that it ist possible to assign a velocity, but I wasn't lucky, searching for it.
It might be done with the set "region xy temperature T" command. But thats not a satisfactory solution.

I hope someone can help me.

Thanks
RobertG

Hi,

I am trying to do a problem similar to example in.mesh_tet. While executing in liggghts, I repeatedly get the error message "Set command with no atoms existing". While running the in.mesh_tet example there was no problem like this.

I am attaching my command file, model and log file.

Can anyone please help me with this problem?

Hi all,

I want to find the maximum y-coordinate of the particles in my model during the simulation run. Can someone help me or give me any clues?

Many thanks,

Su

Hello!

Hi,

I have to define a global variable in Pair_gran_hooke to be used in a compute source file. I have tried many ways but I did not succeed. How is that possible?

Thanks
Mohammad

Is there a possible way to know the number of contacts of each and every particle(may be with the wall or with the other atoms) and write the data(total number of contacts) into a new file?
I tried to follow this FORUM TOPIC but I couldnt figure it out : http://www.cfdem.com/forums/contactatom
It was printing only zeros for every ntimesteps.

Thank you.