View Issue Details
|ID||Project||Category||View Status||Date Submitted||Last Update|
|0001994||OpenFOAM||Bug||public||2016-02-14 12:23||2016-02-15 18:03|
|Platform||GNU/Linux||OS||OpenSuSE||OS Version||Leap 42.1|
|Summary||0001994: MPPIC Implicit Packing Limiting|
|Description||The 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 Reproduce||The attached case illustrates the issue. Running it results in a bed of particles which continually churn.|
|Additional Information||I have a implemented a method of limiting the effect of the Implicit packing model here...|
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.
|Tags||No tags attached.|
|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|