Bin size or skin value

Submitted by Inderjot Kaur on Mon, 01/17/2022 - 22:43

Hi All,
I am trying to simulate normal particle flow falling freely from hopper. I have read some articles on bin size or skin value. There is still some confusion I have. What is the optimal size of bin or skin? I read somewhere that the bin size of about ~ 4 times the particle radius would be fine. Does bin size affect the final solution?

mschramm | Tue, 01/18/2022 - 18:14

Hello,
bin size could affect the solution as you do not want a sphere to travel further than one cell each time step.
This could cause missed interactions.

I believe EDEM recommends 4-6 times smallest particle radius (I don't have a manual in front of me right now...).

Skin size is slightly more abstract.
Bins are set to equal the minimum force carry distance of your simulation (for 99.9% {I made this up...} of simulations here, this will simply be your smallest sphere's diameter) + some skin distance.
Here I put a number either equal to my smallest spheres radius or its diameter (making the bins be 4 times the radius in size).

Inderjot Kaur | Sat, 03/05/2022 - 16:23

Thanks a lot for you reply. I was successful in getting fairly good results with bin size of 4 times the particle radius. I was able to run the script with 400 micron diameter successfully. However, when I am running the same script with 200 micron particle diameter, the simulation stops without error message showing the following:

Primary job terminated normally, but 1 process returned a non-zero exit code. Per user-direction, the job has been aborted.

My problem involves filling a silo with particles under gravity. Initially it would fill the particles for some mass and terminate. I thought it might be due to time step size. I reduced the tiem step from 5e-6 to 1e-6, the simulation ran longer for more mass insertion but eventually terminated. I am suspecting that the memory of the computer might be issue or bin size. Due you have any suggestion what could possibly solve this problem as I am not able to find a solution to this?

Thanks