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IDProjectCategoryView StatusLast Update
0003929OpenFOAMBugpublic2022-11-10 14:51
ReportermaHein Assigned Tohenry  
PrioritynormalSeveritycrashReproducibilityalways
Status resolvedResolutionfixed 
PlatformUnixOSOtherOS Version(please specify)
Product Version10 
Fixed in Versiondev 
Summary0003929: interFoam freezes with empty processors
DescriptioninterFoam freezes at the first time step, when run in parallel with at least one empty processor (e.g. processor with zero cells). There is no error message, it justs keeps running after calculating the Courant number but never continues any further. In contrast, simpleFoam is able to run the exact same case in parallel.

At first, this problem can easily mitigated by adjusting the decomposeParDict, so no processor has zero cells. However, I have one case with dynamic mesh (refiner + distributor), where the distributor actually leads to a processor with zero cells during runtime and thus a crash/freeze.

Maybe this can be considered user error. However, since there is no error message it can be very hard to tackle this issue for a user.
Steps To ReproduceI have attached a simple 2D case. Just run the Allrun script.
TagsNo tags attached.

Activities

maHein

2022-11-09 10:07

reporter  

exampleCase.zip (290,691 bytes)

henry

2022-11-09 10:42

manager   ~0012869

Can you provide funding for this development?

https://openfoam.org/news/funding-2023/

maHein

2022-11-10 08:48

reporter   ~0012870

I expect this to be a bug which can be fixed easily. The error seems to come from the alphaCourantNo.H, which is called in interFoam.C. Here, in line 40 there is a if-statement checking whether the processor mesh has any internal faces:

    if (mesh.nInternalFaces())

Commenting out this line fixes the issue. So why does this case run with pimpleFoam without error? Here, the CourantNo.H is called to compute the Courant number. However, this file has no if-statement checking for internal faces, although the rest of the calculation is similar to alphaCourantNo.H.

henry

2022-11-10 08:53

manager   ~0012871

Is your organisation interested in funding OpenFOAM maintenance?

henry

2022-11-10 14:51

manager   ~0012872

Resolved in OpenFOAM-dev by commits e1c0207695f93a9a2feadb720c10ffff1cb6c9ce and f088d89127dc462266907b05a75ec021f3a40047

Issue History

Date Modified Username Field Change
2022-11-09 10:07 maHein New Issue
2022-11-09 10:07 maHein File Added: exampleCase.zip
2022-11-09 10:42 henry Note Added: 0012869
2022-11-10 08:48 maHein Note Added: 0012870
2022-11-10 08:53 henry Note Added: 0012871
2022-11-10 14:51 henry Assigned To => henry
2022-11-10 14:51 henry Status new => resolved
2022-11-10 14:51 henry Resolution open => fixed
2022-11-10 14:51 henry Fixed in Version => dev
2022-11-10 14:51 henry Note Added: 0012872