Please help me check why my case can't be simulated

MFiX
#1

Please help me check why my case can’t be simulated. Running the case immediately stops, as shown in the picture, without indicating the cause of the error.The first file is a bug report.
si_2023-10-16T224315.667954.zip (24.1 MB)
SI -CGS.zip (36.5 MB)

1
1896×176 48.5 KB

#2

Hi Liuyu - thanks for the report.

It is very odd that MFiX is printing out this garbled message, I’ve never seen this particular problem before.

I found a few issues while going over this.

  1. Your bug report was a little confusing, the first ZIP file contains a project directory SI and inside it another SI subdirectory with another SI.mfx inside. And then a second zipfile SI -CGS.zip - it was not clear to me which one you meant to upload. I’m also confused by the name, CGS is the centimeter-gram-second system which is deprecated and not supported by MFiX. However I think you meant CGP - Coarse-grained particle. Not important but mildly confusing.

  2. I’m sure that at least part of the issue is the space in the directory name SI -CGS. While it would be nice if all software dealt properly with filenames and directory names with spaces in them, this is a common source of trouble. I tested this for the recent 23.3 release but it looks like the SMP solver script still needs some quotes added to it to handle the space in the name - that Starting env OMP_NUM_THREADS line shows the filenames appearing without the protective surrounding quotes that are required for space-containing filenames. I will ensure this works for the next MFiX release.

I renamed the directory SI-CGS and tried again. The simulation started but I got a popup

Error from check_data/check_solids_common_discrete.f:758
Error 2001: No interpolation scheme specified when DES_INTERP_ON
is enabled.

After setting the interpolation scheme to Square DPVM and trying again I got another message about the DES interpolation width. I set this to 0.00236 - the max particle diameter as the tooltip for that input recommends.

After fixing this there’s still a problem running SMP on Windows. The solver starts, prints its initial messages, but exits after a few seconds without any warning. As always, when SMP jobs fail, try the serial (single-CPU) solver.

Running this, I get an out-of-bounds particle warning:

Error: There exists a NORMAL particle in a GHOST cell.
Particle may have gone OUT-OF-BOUNDS.
To resolve this issue, please consider:
 a) Verify all wall boundary conditions are defined
 b) Reducing the value of the variable NEIGHBOR_SEARCH_N (Solids>DEM>Max steps between neighbor search)
 c) Increasing the particle and/or wall stiffness (Solids>DEM>Normal spring constant or Young's modulus)
Current particle location (x, y, z coordinates): 0.5321E-01,  0.1994E-01, -0.4760E-01
Current particle velocity (u, v, w components) :  4.498    ,  -80.15    ,  -52.62
#3

First of all, I apologize to you for any misunderstanding caused by my misnaming the file. Secondly, I modified it according to your suggestions, and it can run, but it is not convergent. Finally, you mentioned that it can run in version 23.3, is my case listed in version 23.2 not running?
SI-CGP.zip (31.6 MB)

#4

It fails in both 23.2 and 23.3 but 23.3 has the improved detection for particles going out of bounds.

#5

Thank you for reminding me, can you help me check why it doesn’t converge.

#6

I suggest using 23.3 and working on the particle-leaving-the-domain problem.

#7

Hello, cgw,this case is ready to run, but the reaction to generate silicon has not yet occurred. I don’t know how to solve this problem, please help me cheak it.
si_2023-10-25T215437.199499.zip (41.2 MB)

#8

Hello,this case is ready to run, but the reaction to generate silicon has not yet occurred. I don’t know how to solve this problem, could you help me check it ? Thank you very much.
si_2023-10-25T215437.199499.zip (41.2 MB)

#9

Please elaborate on what quantities you are monitoring and what you are expecting to see.

#10

I want to monitor the particle size of silicon particles to determine its growth rate, but the reaction to generate silicon did not occur, the reaction rate was zero, and the particle size of silicon did not change.

#11

First you need to fix your mesh because it doesn’t look waterproof.
Second, how fast do you expect to see a change in size? 0.17 seconds is not much to see a change. If I look at your monitor, I see a tiny change in particle size, not sure if it is significant or just round off. You should save your particle data in a vtk file and save diameter and reaction rates so you can do some trouble shooting.

#12

I expect the diameter change to be about 1.575nm/s.