Hello developer
I am using pic method to do the fluidized bed simulation of polysilicon, and I want to detect the change of particle size, but only two of the six reactions that generated silicon did not happen. Could you please help me check what is wrong with my case?
3.4.1hopper-3D-pic.zip (77.1 MB)
Hello,developers.
Could you please help me check what is wrong with my case?
Sorry for the delay, we’ve been a bit busy preparing for the upcoming 23.3 release. We appreciate your patience.
I don’t have a complete answer yet, but the first thing I noticed is this message
DLSODA- At T (=R1) and step size H (=R2), the
corrector convergence failed repeatedly
or with ABS(H) = HMIN
appears over 100,000 times in the stderr file. I’m not sure exactly what this means, but it can’t be good! DLSODA is part of the venerable ODEPACK library that MFiX uses to solve differential equations- it is having some trouble solving the reaction system.
I cannot get your case to run at all. There is an error in get_stl_data, it’s having trouble reading the STL files. I am not sure what the issue is.
I also note that the ZIP file you uploaded has a lot of extra contents - there is another zip file inside, as well as the mfixsolver binary and the entire build subdirectory - we do not need all of this. If you use Submit bug report from the main MFiX menu, a ZIP file will be created that contains just the files that we need for troubleshooting. Can you do this and try uploading again? Perhaps there’s an issue with the file you uploaded. Thanks.
I have another question. I want to simulate a fluidized bed with a particle volume fraction of 0.6, but there are too many particles. What parameters should I adjust to reduce the particle number?
Number of particles is a function of domain size, particle size and packing density.
But particle density and diameter are also determined, I would like to use the "particle_input " in DEM method, but there are too many particles. Therefore, is there any better suggestions to achieve the volume fraction of 0.6 under certain particle density and diameter?In addition, I have uploaded the bug report above, please help me to check why the reaction of generating silicon did not happen?Thank you~
I don’t understand your question. There is no way to reduce the number of particles, if they have a fixed size and you fill a region with them to a density of 0.6, there will be a certain number of them determined by the size of the particles and the size of the region. You can’t get the same packing density with fewer particles, unless they are larger.
However you could try the CGP (Coarse-Grain Particle approach) which does not attempt to track every particle but tracks them in “bunches” instead.
Also, please do not zip up the entire project directory - use the “Submit bug report” which makes for a smaller upload.
The simulation you uploaded - hopper3_2023-09-28T213752.268480.zip - does not run for me. The IC region “bed” is overpacked - you have des_epg_clip = 0.42
The upcoming 23.3 MFiX version will print out warnings for overpacked IC regions.
Also due to the excessively large number of particles, I cannot effectively run this case - it would need a large number of CPUs to get anywhere.
– Charles
Sorry for replying to you so late. I am very sorry for the bug report I uploaded earlier. I have uploaded it again, but this is a report under volume fraction=0.045 because the simulation cannot proceed at volume fraction=0.6, please help me check why the reaction to generate silicon did not occur.
si_2023-10-10T174047.276535.zip (94.4 MB)