Hello LIGGGHTERS,
Recently, I tried to simulate bin flow tutorial existing in the forum. By examination of the results, I noticed that the my output might not be coherent with real physic of the system. I have attached two images to this post which shows there are regular spaces between certain value of particles while they fall through the bin. The images correspond to 1st time step and 2nd time step.
I suspicious about the input script. Do you think this problem can be related to insert_every value?
fix ins all insert/rate/region seed 32452843 distributiontemplate pdd nparticles 150000 particlerate 150000 insert_every 1000 &
overlapcheck yes vel constant 0. 0. -1.0 region factory ntry_mc 10000
Thanks you for sharing your comments with me in advance.
| Attachment | Size |
|---|---|
 first_time_step.jpg | 113.59 KB |
| 2nd_time_step.jpg | 206.82 KB |
richti83 | Wed, 02/06/2019 - 08:13
Do you mean the vertical gap
Do you mean the vertical gap in the middle ? This is due the processor boundary as the insert command can not "see" the particles allready inserted by the other processor. You can change processors 1 1 * to only devide the simulation domain in z-direction.
Or do you mean the gaps between the horizontal layers ? They result from the fact that particles starts at discrete timesteps with an initial velocity and than accelerate due gravity. This is expected behaviour. Keep in mind that the insert methods only achieve a voidfraction of approx. 30% so the filling process itself is not comparable to real world.
emahvelati | Wed, 02/06/2019 - 17:54
Insert_every value
Dear richti83,
Thanks for your explanation. Actually. I meant both gaps, vertical and horizontal ones. I did few simulations even in serial mode without decomposition and I observed the same gaps. I also deactivated the processor part in LIGGGHTS input script.
As I pointed out in the post, I was suspicious about the insert_every value . I just changed its value to 500 which means each 500 time steps, it inserts the particles in the way that it still respect to particle rate. It removed the gaps which can be more realistic.