[WhiteW]

Dear all,
I'm using OpenFOAM v2012 on a computer with the Ubuntu 20.04 OS.
Now I also installed it (v2012) on a new computer with a more recent hardware, the new operative system is Ubuntu 21.10.

I'm doing some test to check the performances; however I'm registering different behaviours between the two computers.
The sequece of operations involves:
surfaceFeatureExtract
blockMesh
snappyHexMesh
decomposePar
extrudeMesh
createPatch
potentialFoam
changeDictionary
buoyantBoussinesqSimpleFoam

The resulting meshes are identical, indeed the two checkMesh logs give the same output.
All the logfiles are identical (as expected with different execution times) until the execution of potentialFoam.
The first difference I noticed is in potentialFoam: the Interpolated velocity error is 1.46919e-06 for PC1 and 0.00893802 for PC2

Finaly the buoyantBoussinesqSimpleFoam of PC2 diverges after few iterations, the maximum velocity is very high since iteration 1.
The buoyantBoussinesqSimpleFoam results in PC2 diverges also skipping the potentialFoam.

Why the results are different?
Attached are the potentialFoam and buoyantBoussinesqSimpleFoam log files.
comparison.zip

Thanks!
WhiteW