snappyHexMesh maxGlobalCells is limited by int32 limit 2,147,483,647 (2.147 Billion)
Description of error
SnappyHexMesh crashes whenever one wants to extend the variable maxGlobalCells past the int32 upper limit of 2,147,483,647.
Here the error when trying to set it as 4,000,000,000 (4e9):
Expected integral (int32), value out-of-range on line 0: double 4000000000
I tried out setting it to 4000000000, 4e9, 4000000000L - all resulting in the same error.
What to fix
Read in the variable from the dictionary in long representation - is that possible? Elsewise read it in as double and check as double. We do not need precice checks so double check would be fine.
Who would benefit from this change
We want to make OpenFoam exa-scale ready, so this upper limit needs to be adjusted. I expect to surpass this upper limit for the exaFoam Grand Challenge CRM-HL during meshing process.