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IDProjectCategoryView StatusLast Update
0003509OpenFOAMBugpublic2020-11-21 19:51
ReporterQiangAssigned Tohenry 
Status closedResolutionsuspended 
PlatformWSLOSUbuntuOS Version18.04
Product Versiondev 
Fixed in Version 
Summary0003509: Phase mass/volume imbalance of the VoF family solvers due to using AMI
DescriptionI have tested the VoF family solvers under almost all versions of OF and found when the AMI approach with a baffle inside the fluid is employed, like mixerTank2D case, the phase mass/volume imbalance or mass loss problem will take place. With every timestep, it loses a certain amount of fluid, for the attachment case, the fluid volume loss fraction, only after running 12.5 seconds, had reached 37.34%. The level of liquid in the tank has dropped remarkably in the condition of having not any outlet due to this volume/mass loss.

Through monitoring the weightedSum(phi) of the patch AMI1 and AMI2 found this phase volume/mass loss possibly comes from the inconsistent interpolation when two patches slides and couples with each other. how to forcefully keep balance when interpolation may be a key problem.
TagsNo tags attached.



2020-06-14 20:08


mixerTankAMI3D_forBugReport.tar.gz (11,163 bytes)


2020-06-14 20:10


Volume evolution.PNG (101,189 bytes)
Volume evolution.PNG (101,189 bytes)
weightedSum(phi) difference between AMI1 and AMI2.PNG (613,946 bytes)


2020-06-14 20:13


AMI1.dat (177,600 bytes)
AMI2.dat (183,932 bytes)
volFieldValue.dat (35,141 bytes)


2020-06-14 20:34

manager   ~0011394

Yes this is a well known problem with the current AMI implementation and has been reported several times. If you search for AMI you will see the previous discussions on this issue.


2020-06-17 18:17

reporter   ~0011395

Sure. I have reviewed the most of related items from this tracking system and CFD-online forum. I saw there were still a lot of struggles to try to solve this issue, although it had a long history. And I found the pimpleDyMFoam with AMI and VoF family solvers with MRF have already had some improvements to keep the mass/volume conversion, but the issue on VoF solvers with AMI is still there about several years and across the several versions.

In addition, it seems to even turn worse and worse, the following figure gives a comparison between two old snapshots of dev-490a29719073e724 by released on Sep. 06, 2018 and dev-fa9cccf11df67a1f on Jun. 11, 2020. Maybe, it is a hint what you have changed, thus it turn worse.

By the way, could you of have any plan to fix this ill in the near future, or if possible, could you give some hints or clues on how to fix it? Finally, thank you very much.


2020-06-17 19:35

manager   ~0011396

This is a particularly tricky problem to solve and requires funding for development and maintenance:


2020-06-22 09:22

reporter   ~0011401

Thank you for all the replies.

Honestly, this bug has resulted in many abnormal results when the VoF solvers with AMI were employed and thus incurred the OF creditworthiness loss. Of course, I can understand your demand for funding to struggling OF. If possible, in the future once I get a financial aid, I will attend the Maintenance Plans.

On this bug, I have spent several days to find a workaround to forcefully keep mass balance when using AMI interpolation, I still need some additional tests to guarantee the validity of this remedy.

Whatever, thank you very much for sharing the excellent OF codes with the community.


2020-11-21 19:51

manager   ~0011704

Pending funding

Issue History

Date Modified Username Field Change
2020-06-14 20:08 Qiang New Issue
2020-06-14 20:08 Qiang File Added: mixerTankAMI3D_forBugReport.tar.gz
2020-06-14 20:10 Qiang File Added: Volume evolution.PNG
2020-06-14 20:10 Qiang File Added: weightedSum(phi) difference between AMI1 and AMI2.PNG
2020-06-14 20:13 Qiang File Added: AMI1.dat
2020-06-14 20:13 Qiang File Added: AMI2.dat
2020-06-14 20:13 Qiang File Added: volFieldValue.dat
2020-06-14 20:34 henry Note Added: 0011394
2020-06-17 18:17 Qiang File Added: mass_loss_comparison_across_different_OFversion.PNG
2020-06-17 18:17 Qiang Note Added: 0011395
2020-06-17 19:35 henry Note Added: 0011396
2020-06-22 09:22 Qiang Note Added: 0011401
2020-11-21 19:51 henry Assigned To => henry
2020-11-21 19:51 henry Status new => closed
2020-11-21 19:51 henry Resolution open => suspended
2020-11-21 19:51 henry Note Added: 0011704