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IDProjectCategoryView StatusLast Update
0001994OpenFOAM[All Projects] Bugpublic2016-02-15 18:03
ReporterwillAssigned Tohenry 
PrioritynormalSeverityfeatureReproducibilityN/A
Status resolvedResolutionfixed 
PlatformGNU/LinuxOSOpenSuSEOS VersionLeap 42.1
Product Versiondev 
Fixed in Version 
Summary0001994: MPPIC Implicit Packing Limiting
DescriptionThe Implicit packing model in MPPIC is pretty good at maintaining a maximum volume fraction of particles, but it suffers from problems in simulating still beds of particles. They tend to continually scatter and churn.

This is an issue generally with MPPIC and is in part due to the extreme non-linearity of the packing force. The Explicit model handles this problem by severely limiting the applied force. This works pretty well. It would be useful to have something similar for the Implicit model.
Steps To ReproduceThe attached case illustrates the issue. Running it results in a bed of particles which continually churn.
Additional InformationI have a implemented a method of limiting the effect of the Implicit packing model here...

https://github.com/OpenFOAM/OpenFOAM-dev/compare/master...will-bainbridge:MPPICImplicitPackingModelLimiting

Essentially, all this does is calculate the required correction flux then compare it with the existing particulate flux. If the particles are already moving in the required direction, only the difference between the existing and correction flux is applied. If they are already "correcting" in excess of what is needed, nothing is done.

This stops a lot of the churning in the attached case, though the scattering behaviour is still present. I don't know what to do about that.

I have some movies of the change, but they are too big to upload. I'll generate some smaller ones in a bit. I'll have to run the case again.
TagsNo tags attached.

Activities

will

2016-02-14 12:23

manager  

silo.tar.gz (4,285 bytes)

will

2016-02-14 12:50

manager  

movieLowRes.ogv (1,765,541 bytes)

henry

2016-02-15 18:03

manager   ~0005946

Thanks for providing this development Will.

Resolved by commit 567236ef96a38cc4eb54d2ca2a8ece8a1ab0d255

Issue History

Date Modified Username Field Change
2016-02-14 12:23 will New Issue
2016-02-14 12:23 will File Added: silo.tar.gz
2016-02-14 12:50 will File Added: movieLowRes.ogv
2016-02-15 18:03 henry Note Added: 0005946
2016-02-15 18:03 henry Status new => resolved
2016-02-15 18:03 henry Resolution open => fixed
2016-02-15 18:03 henry Assigned To => henry